Abstract
Abstract: Cerrenaceae is a small family of polypores and hydnoid fungi in the order Polyporales (Basidiomycota). The family consists of white-rot fungi, some of which are serious tree pathogens. Combining morphological evidence with a phylogenetic dataset of six genetic markers, we revise generic concepts in the family and propose a seven-genus classification system for the family. Two genera are introduced as new: the monotypic Acanthodontia for Radulodon cirrhatinus, and Lividopora for the Rigidoporus vinctus complex. We re-introduce the name Somion for the Spongipellis delectans complex. Other recognized genera in the family are Cerrena, Irpiciporus, Pseudolagarobasidium, and Radulodon. New species introduced are Irpiciporus branchiformis from Tanzania, Lividopora armeniaca, and L. facilis from Southeast Asia, and Somion strenuum from East Asia. We provide nomenclatural comments on all the names combined to the above Cerrenaceae genera and typify Cerrena unicolor, C. zonata, Polyporus carneopallens (= L. vincta), Somion occarium, and S. unicolor. The genus Hyphoradulum belongs to Cystostereaceae (Agaricales), and we transfer the type species H. conspicuum to Crustomyces. Our study highlights the importance of integrating different basidiocarp types in analyses when revising genus classification in macrofungi.
Citation: Miettinen O, Vlasák J, Larsson E, Vlasák J Jr., Seelan JSS, Hernawati, Levicky Q, Larsson K-H, Spirin V (2023). A revised genus-level classification for Cerrenaceae (Polyporales, Agaricomycetes). Fungal Systematics and Evolution 12: 271–322. doi: 10.3114/fuse.2023.12.14
Keywords: hydnoid fungi, hyphal system, new taxa, pathogenic fungi, polypore, root rot disease, systematics, taxonomy
INTRODUCTION
A phylogenetic framework became available to mycologists in the 1990s with the onset of easy and low-cost DNA sequencing. Its impact has step by step penetrated fungal systematics and classification. Hibbett et al. (2007) established a classification system at the order level and above. Justo et al. (2017) extended the phylogeny-based classification to the family level in the order Polyporales, which is dominated by macrofungal basidiocarp types, polypores and crusts (corticioid fungi). Family concepts in this scheme are monophyletic groups defined by their genetic similarity; morphology was not – and one could argue cannot be – a leading principle when designing fungal classification at the higher levels.
Yet DNA-based phylogenetics does not liberate us from considering morphological or ecological characters in taxonomy. Most species can be and are being defined by morphological or ecological traits. Some of the families might be characterized morphologically, others not; but between the family and species level there is a space, genus-level and intermediary ranks, where morphology and phylogenetics both can and should define classification. The question how to define monophyletic genera so that they would be morphologically identifiable whenever possible is an important consideration when revising classification. Each family is likely to represent a unique dilemma in this sense, and it is becoming evident that only suboptimal solutions exist in some cases, thus is the level of morphological plasticity in fungi.
The subject of our paper is one of the families Justo et al. (2017) established, the Cerrenaceae. This small family includes wood decomposers and tree pathogens. Basidiocarp morphology varies from polypores such as Antrodiella p.p., Cerrena, Rigidoporus p.p., and Spongipellis p.p. (Fig. 1) to hydnoid fungi such as Pseudolagarobasidium and Radulodon (Fig. 2). When establishing the genus, Justo et al. did not elaborate on how the family might be delimited morphologically or how to classify species diversity within it. Here we have studied most of the species complexes and all the genera in the Cerrenaceae, and propose a genus classification for the family. This task exemplifies the problem of balancing morphological signal with phylogenetics – in essence between the extremes of many small genera or a few larger ones. As we will show below, neither solution is perfect. Both solutions would create a situation where morphological genus definition is difficult, and yet one of them has to be implemented to avoid non-phylogenetic genera.
Fig. 1.
Poroid members of the Cerrenaceae. A. Cerrena albocinnamomea (Niemelä 6372). B. Cerrena unicolor (Miettinen 16901). C. Cerrena zonata (Miettinen 13798). D. Lividopora benetosta (Miettinen 18135). E. Somion occarium (Overall, K(M) 159049). F. Somion strenuum (holotype). G. Somion tomsovskyi (Vlasák Jr., JV 1307/8). Scale bars = 1 cm.
Fig. 2.
Hydnoid and irpicoid representatives of Cerrenaceae. A. Acanthodontia cirrhatina (Miettinen 13717). B. Irpiciporus pachyodon (Spirin 13785). C. Radulodon erikssonii (Miettinen 10977). D. Pseudolagarobasidium subvinosum in herbarium (Wu 8609). Scale bars = 1 cm.
If polypores and hydnoid fungi would be viewed in isolation, one could arrive at two classification systems that do a good job creating monophyletic, morphologically easy-to-recognize genera within the Cerrenaceae. However, these two schemes would not be mutually compatible (phylogenetically logical). We argue that genus taxonomy should be revised in overview papers such as Justo & Hibbett (2011), Miettinen et al. (2012), Chen et al. (2021), Savchenko et al. (2021) and Li et al. (2022) to mention a few good examples from corticioid fungi and polypores. These papers are based on large, multi-marker, and taxonomically inclusive datasets. In contrast, many current taxonomic papers treat each case in isolation and routinely erect new genera for newly-discovered clades in the most recent phylogram without the benefit of a wider perspective.
Following is a short introduction to currently recognized genera in the Cerrenaceae.
Antrodiella is a polypore genus that historically included dimitic white-rot species with small pores and spores. Miettinen et al. (2012) suggested a narrower, monophyletic concept for the genus, a concept that was adopted by some subsequent authors (Yuan 2014, Westphalen et al. 2019) but not all (Ryvarden 2018, 2020a). Antrodiella sensu stricto belongs to the Steccherinaceae. In his paper on Chinese Antrodiella, Yuan (2014) showed that A. albocinnamomea and A. zonata are related to Cerrena and transferred them to Cerrena, though without wider consideration of genus classification in the Cerrena clade (Cerrenaceae). We show in this paper that A. multipileata also belongs to the Cerrenaceae.
Cerrena, as currently recognized, is a small polypore genus perhaps best known for Cerrena unicolor, a wide-spread temperate species in the northern hemisphere. Cerrena unicolor has two relatives (C. cystidiata and C. ‘gilbertsonii’). As mentioned, Yuan (2014) also included two former Antrodiella species in the genus as C. albocinnamomea and C. zonata. In our experience, Cerrena unicolor is a phytopathogen, and Dai et al. (2007) list C. zonata as a heartwood rotter of living trees. Cerrena unicolor has been studied for its enzymatic capabilities (Janusz et al. 2007, Elisashvili et al. 2010, Lisova et al. 2010, Hartikainen et al. 2016, Janusz et al. 2018), as has C. albocinnamomea (Yuan et al. 2012).
Pseudolagarobasidium contains nine temperate to tropical species with thin, hydnoid basidiocarps. The current genus concept derives from Hallenberg et al. (2008) and Nakasone & Lindner (2012). Two species are known to be tree pathogens, causing root rot (Jang & Chen 1985, Wood & Ginns 2006), while others have been reported as endophytes and saprotrophs (Hallenberg et al. 2008).
Radulodon contains several light-coloured hydnoid species. Nakasone & Lindner (2012) narrowed the genus concept by excluding a set of species, and we continue here, leaving two temperate species and a recently described species from the Eastern Himalayas (Wang & Dai 2022). Radulodon spp. are apparently saprotrophs of angiosperms.
Rigidoporus in the traditional sense is a highly polyphyletic genus. Species placed under it are found in two orders (Hymenochaetales and Polyporales) and within the Polyporales in several families, the largest of which is the Meripilaceae (Justo et al. 2017, Wu et al. 2018). Justo et al. (2017) showed that the Rigidoporus vinctus complex belongs to the Cerrenaceae. It is clear that Rigidoporus in the strict sense is not related, and consequently a better-fitting genus has to be found for the R. vinctus complex. This species group includes effused polypores mostly found in the tropics. Several species (previously called varieties) are known as tree pathogens in the tropics and New Zealand (“red root-rot”, Setliff & Mesner 1971, Setliff 1972b, Hood & Dick 1988). They have also been detected as endophytes of rubber (Martin et al. 2015). We revise this species complex here.
Spongipellis is a small genus of polypores comprising about 10 species. Its current concept was introduced by Bondartsev & Singer (1941), but their concept has been shown to be polyphyletic and their species concepts outdated (Tomšovský 2012, Dvořák et al. 2014). Spongipellis in the strict sense is related to Meripilaceae, whereas the species complexes S. delectans and S. pachyodon are in the Cerrenaceae (Justo et al. 2017, Kotiranta et al. 2017). The genus name Irpiciporus is available for the S. pachyodon species complex and has been put in use recently (Wang & Dai 2022). Species of the S. delectans complex have been reported to be serious tree pathogens of oaks (Ljubarsky 1934, Černý 1979, Dai et al. 2007). Wang & Dai (2022) recently described the genus Pseudospongipellis for the S. delectans complex. We re-introduce here the older genus name Somion for this clade. Nakasone & Ortiz-Santana (2022) added several species.
In this paper, we comment on all names combined to Cerrena, Irpiciporus, Pseudolagarobasidium, and Radulodon. For Spongipellis nomenclature, see Spirin et al. (2022), who focused on Spongipellis sensu stricto. We comment further on Spongipellis names here, including all names we know are associated with the Cerrenaceae, but provide no exhaustive checklist for this genus.
MATERIALS AND METHODS
We studied 152 specimens from the following fungaria: H, O, BPI, CFMR, DAOM, FH, FLOR, GB, K, NY, PC, PRM, and W (Thiers 2023). JV refers to the personal fungarium of Josef Vlasák. The basic mountant used in microscopic descriptions is Cotton Blue (CB). We measured 30 basidiospores per specimen and 20 hyphae for each hyphal type for each specimen used in making the descriptions. When presenting measurements of basidiospores, 5 % extreme values from both ends of variation are given in parentheses. For hyphal measurements, the 20 % tails are placed in parentheses. The following abbreviations are used in descriptions below: L – mean spore length, W – mean spore width, Q – L/W ratio, n – number of measurements per specimens. For more details on microscopic routine, consult Miettinen et al. (2018).
DNA extractions were performed as described in Miettinen et al. (2012), Spirin et al. (2013), and Gutaker et al. (2017). The nuclear ribosomal internal transcribed spacer (ITS) region was amplified by PCR and sequenced using primers ITS1, ITS2, ITS5, ITS4, and LR22; nuclear large subunit or 28S (LSU) with CTB6, LR5 and LR7; and mitochondrial small subunit or 16S (mtSSU) with MS1 and MS2 (White et al. 1990, Vilgalys lab 1992 https://sites.duke.edu/vilgalyslab/rdna_primers-For-Fungi, Garbelotto et al. 1997); mitochondrially encoded ATP synthase membrane subunit 6 (ATP6) with ATP6-1, -3, and -4 (Kretzer & Bruns 1999); DNA-directed RNA polymerase II largest subunit RPB1 encoding gene (RPB1) with rpb1-gAf and rpb1-fCr (Matheny et al. 2002); and translation elongation factor 1-alpha (TEF1) with EF1-983F (Rehner & Buckley 2005) and EFgr (Rehner, GCAATGTGGGCRGTRTGRCARTC). Sanger sequencing was mostly conducted at Macrogen (Korea and Netherlands) and the Academy of Sciences of the Czech Republic (České Budějovice, Czech Republic). Also, Illumina NextSeq data were used to retrieve markers from partial genome sequences for a few specimens as described in Viner et al. (2021). Newly created sequences were submitted to GenBank (Sayers et al. 2022, Table 1).
Table 1.
List of specimens with DNA sequences used in this study. Codes refer to INSDC or UNITE accession numbers. Newly produced sequences are printed in bold. Asterisk (*) denotes cultures as the origin of the sequences. Abbreviation of provinces/states follows ISO 3166-2.
| Species | Specimen / culture* | Country (province/state) | GenBank accession numbers | |||||
|---|---|---|---|---|---|---|---|---|
| ITS | LSU | mtSSU | ATP6 | RPB1 | TEF1 | |||
| Acanthodontia cirrhatina | holotype | Malaysia | OR262205 | — | — | — | — | — |
| Miettinen 13717 | Indonesia (SB) | OR262179 | OR262179 | — | OR296385 | OR296392 | OR296407 | |
| Cerrena albocinnamomea | Miettinen 10511 | China (JL) | OR262168 | OR262168 | OR295446 | OR296382 | — | OR296402 |
| holotype of C. aurantiopora | South Korea | FJ821532 | — | — | — | — | — | |
| — | KC485522 | KC485539 | — | — | — | — | ||
| Cerrena cystidiata | Brazil | MZ649034 | MZ649034 | — | — | — | — | |
| Cerrena ‘gilbertsonii’ | D. Vlasák (JV 1609/29) | Guadeloupe | OR262202 | — | — | — | OR296399 | — |
| Vandevender 94-144 | Mexico | OR262171 | OR262171 | OR295447 | — | — | — | |
| Cerrena multipileata | J. Vlasák (JV 1407/63) | Costa Rica | OR262201 | OR262201 | — | — | OR296398 | — |
| Ryvarden 43881 | Costa Rica | OR262155 | OR262155 | OR295442 | — | — | — | |
| Kout (JV 0611/A36) | Guatemala | OR262203 | — | — | — | — | — | |
| Cerrena sp1 | China | KX527879 | — | — | — | — | — | |
| China | MK247953 | — | — | — | — | — | ||
| China | MT908560 | — | — | — | — | — | ||
| Vietnam | MT269762 | — | — | — | — | — | ||
| Vietnam | MT269763 | — | — | — | — | — | ||
| Cerrena sp2 | China | OP022000 | — | — | — | — | — | |
| Indonesia | KJ654531 | — | — | — | — | — | ||
| Taiwan | MN592928 | — | — | — | — | — | ||
| Cerrena unicolor | Antarctica | HM589361 | — | — | — | — | — | |
| Argentina (TF) | MH019790 | — | — | — | — | — | ||
| Canada (ON) | MH855029 | — | — | — | — | — | ||
| China (XJ) | OM100740 | OM083972 | ON417068 | — | ON424672 | ON424825 | ||
| China | JQ798288 | — | — | — | — | — | ||
| China | MW467890 | — | — | — | — | — | ||
| Czech Republic | FJ821536 | — | — | — | — | — | ||
| Finland | FN907915 | FN907915 | — | — | — | — | ||
| Italy | MK581063 | — | — | — | — | — | ||
| Japan | LC415531 | — | — | — | — | — | ||
| Uotila 47558 | Kyrgyzstan | OR262167 | — | — | — | — | — | |
| Serbia | MW485440 | — | — | — | — | — | ||
| South Korea | MN294859 | — | — | — | — | — | ||
| Sweden | JN710525 | JN710525 | JN710663 | JN710614 | — | JX109891 | ||
| Turkey | MK120293 | — | — | — | — | — | ||
| United Kingdom | MZ159683 | — | — | — | — | — | ||
| USA (MA) | KP135304 | KP135209 | — | — | KP134874 | — | ||
| Uzbekistan | MT526291 | — | — | — | — | — | ||
| Cerrena zonata | Genevieve Gates 39555 | Australia (TAS) | OR262160 | OR262160 | — | — | — | — |
| Bhutan | UDB0780153 | — | — | — | — | |||
| Miettinen 9773 | China (YN) | OR262157 | OR262157 | — | — | — | — | |
| Miettinen 9889/OMC 13* | China (YN) | OR262158 | OR262158 | OR295443 | OR296380 | OR296390 | OR296401 | |
| Miettinen 13798 | Indonesia (SB) | OR262166 | OR262166 | — | — | — | — | |
| Japan | LC631683 | — | — | — | — | — | ||
| New Zealand | HQ533016 | — | — | — | — | — | ||
| South Korea | MN294861 | — | — | — | — | — | ||
| Vietnam | OP985107 | — | — | — | — | — | ||
| Crustomyces albidus | holotype | China (YN) | ON117191 | ON117175 | — | — | — | — |
| Crustomyces isabellinus | Vietnam | ON117185 | ON117170 | — | — | — | — | |
| Crustomyces laminiferus | Costa Rica | EU118622 | — | — | — | — | — | |
| Crustomyces sp. | China | ON117190 | ON117174 | — | — | — | — | |
| Crustomyces subabruptus | France | MF183941 | — | — | — | — | — | |
| Spirin 4826 | Russia (LEN) | OR262177 | — | — | — | — | — | |
| Crustomyces tephroleucus | holotype | China (HI) | MF290417 | MF290415 | — | — | — | — |
| Cymatoderma sp. | USA (FL) | KY948826 | KY948872 | — | — | KY948971 | — | |
| Cymatoderma africanum | Niemelä 8803 | Mozambique | OR236211 | OR236211 | OR295457 | OR296389 | — | OR296425 |
| Cymatoderma caperatum | Venezuela | JN710529 | JN710529 | JN710666 | JN710617 | — | — | |
| Cystostereum crassisporum | holotype | China (GX) | ON117193 | ON117179 | — | — | — | — |
| Cystostereum murrayi | Germany | MH855588 | MH867098 | — | — | — | — | |
| Cystostereum submurrayi | holotype | China (JX) | ON117192 | ON117177 | — | — | — | — |
| Effusomyces thailandicus | Thailand | ON117194 | ON117180 | — | — | — | — | |
| Hyphoradulum conspicuum | holotype | Czech Republic | OR262206 | — | — | — | — | — |
| Irpiciporus branchiformis | holotype | Tanzania | OR262193 | OR262193 | — | — | — | OR296421 |
| Irpiciporus mollis | Dollinger 770 | USA (FL) | OR262192 | — | — | — | — | OR296420 |
| USA (MA) | KP135302 | KP135288 | — | — | KP134875 | — | ||
| J. Vlasák (JV 0709/174) | USA (VA) | OR359379 | OR359379 | — | — | — | OR387174 | |
| USA | DQ249277 | AY629322 | AFTOL705 | EU339271 | — | DQ028599 | ||
| Irpiciporus pachyodon | Heilmann-Clausen 07-286 | Bulgaria | OR262165 | OR262165 | — | — | — | — |
| J. Vlasák (JV 9311/1) | Czech Republic | OR262191 | OR262191 | — | — | — | OR296419 | |
| Kotlaba (JV 1611/1) | Czech Republic | OR253988 | OR253988 | OR295456 | OR296388 | OR296395 | OR296422 | |
| Czech Republic | HQ728293 | HQ729003 | — | — | — | — | ||
| Italy | AY849307 | — | — | — | — | — | ||
| Irpiciporus sinuosus | holotype | China (YN) | KX161649 | KX161658 | — | — | — | OM982699 |
| Thailand | MK589288 | — | — | — | — | — | ||
| Irpiciporus sp. | Ecuador | KX161650 | KX161659 | — | — | — | — | |
| Lividopora armeniaca | isotype | Malaysia | KY953211 | KY953211 | OR291311 | OR296404 | KY953212 | OR296384 |
| Lividopora benetosta | Cameroon | KJ831816 | — | — | — | — | — | |
| Cameroon | KJ831817 | — | — | — | — | — | ||
| Cameroon | KJ831819 | — | — | — | — | — | ||
| Cameroon | KJ831837 | — | — | — | — | — | ||
| Cameroon | KJ831838 | — | — | — | — | — | ||
| China (GD) | KU904221 | — | — | — | — | — | ||
| China (HI) | KX013197 | — | — | — | — | — | ||
| China (HK) | KU194316 | — | — | — | — | — | ||
| Härkönen K778 | China (HN) | OR262204 | — | — | — | — | — | |
| Härkönen K8 | China (HN) | OR262170 | — | — | — | — | — | |
| Miettinen 10225 | China (YN) | OR262178 | — | — | — | — | — | |
| French Polynesia | MZ996950 | — | — | — | — | — | ||
| French Polynesia | MZ996951 | — | — | — | — | — | ||
| French Polynesia | MZ996952 | — | — | — | — | — | ||
| India | OM033590 | — | — | — | — | — | ||
| Miettinen 8823.2 | Indonesia (RI) | OR262156 | — | — | — | — | — | |
| Indonesia (RI) | KJ654526 | — | — | — | — | — | ||
| Indonesia (RI) | KJ654534 | — | — | — | — | — | ||
| Miettinen 9166.5 | Indonesia (PA) | OR262162 | OR262162 | OR295445 | OR296381 | — | — | |
| Miettinen 9176.2 | Indonesia (PA) | OR262163 | — | — | — | — | — | |
| Malaysia | HQ400710 | — | — | — | — | — | ||
| Hallenberg 15301 | New Zealand | OR262161 | — | — | — | — | — | |
| ICMP 18224* | New Zealand | OR262169 | — | — | — | — | — | |
| New Zealand | MN007016 | — | — | — | — | — | ||
| Papua New Guinea | KR015166 | — | — | — | — | — | ||
| Papua New Guinea | KR015237 | — | — | — | — | — | ||
| Papua New Guinea | KR016181 | — | — | — | — | — | ||
| Philippines | MK817568 | — | — | — | — | — | ||
| Philippines | MT597859 | — | — | — | — | — | ||
| Miettinen 18035 | Puerto Rico | OR262175 | OR262175 | OR295450 | — | — | — | |
| Miettinen 18135 | Puerto Rico | OR262176 | — | — | — | — | OR296406 | |
| Taiwan | MZ423082 | — | — | — | — | — | ||
| Thailand | LC269928 | — | — | — | — | — | ||
| Thailand | MG545057 | — | — | — | — | — | ||
| Lividopora facilis | isotype | Indonesia (RI) | OR262154 | OR262154 | OR295441 | OR296379 | — | OR296400 |
| Lividopora subvincta | holotype | Zimbabwe | OR262197 | — | — | — | — | — |
| Savchenko 171129/1309A | Kenya | OR262196 | — | — | — | — | — | |
| CFMR ECS-194-R* | Tanzania | KY948734 | KY948873 | OR295449 | — | KY948953 | — | |
| Lividopora vincta | Gazis et al. NHB39* | Brazil (PA) | OR262173 | — | — | — | — | — |
| J. Vlasák (JV 1704/102) | Costa Rica | OM669884 | — | — | — | — | — | |
| Mexico | KU747939 | — | — | — | — | — | ||
| Gazis et al. MS512* | Peru | OR262172 | OR262172 | — | — | — | — | |
| Peru | KJ831895 | — | — | — | — | — | ||
| Peru | KJ831906 | — | — | — | — | — | ||
| Peru | KJ831912 | — | — | — | — | — | ||
| Peru | KJ831915 | — | — | — | — | — | ||
| Peru | KJ831927 | — | — | — | — | — | ||
| Peru | KJ831935 | — | — | — | — | — | ||
| Peru | KJ831950 | — | — | — | — | — | ||
| Peru | KJ832036 | — | — | — | — | — | ||
| Miettinen 17916/OMC 1567* | USA (FL) | KY948735 | KY948874 | — | — | KY948954 | OR296405 | |
| Panus conchatus | Finland | JN710579 | JN710579 | JN710695 | JN710643 | — | — | |
| Puerto Rico | OM337524 | OM337524 | — | — | JACDTX010000312 | JACDTX010000141 | ||
| Panus lecomtei | USA (AZ) | KP135328 | KP135233 | — | — | KP134877 | — | |
| Parvodontia austrosinensis | China (GX) | ON117195 | ON117183 | — | — | — | — | |
| Pseudolagarobasidium acaciicola | China | MK247443 | — | — | — | — | — | |
| China | MT814716 | — | — | — | — | — | ||
| India (AP) | KR149461 | — | — | — | — | — | ||
| India | HQ323693 | — | — | — | — | — | ||
| India | JX886000 | — | — | — | — | — | ||
| India | KP297894 | — | — | — | — | — | ||
| India | MK163558 | — | — | — | — | — | ||
| South Africa | DQ517882 | EU569321 | — | — | — | — | ||
| South Africa | DQ517883 | — | — | — | — | — | ||
| Thailand | KF673346 | — | — | — | — | — | ||
| Pseudolagarobasidium baiyunshanensis | China (GD) | MT428549 | MT428547 | — | — | — | — | |
| China (GD) | MT428550 | MT428548 | — | — | — | — | ||
| Pseudolagarobasidium belizense | isotype | Belize | JQ070173 | — | — | — | — | — |
| Gazis et al. VPB197* | Brazil (PA) | OR262174 | OR262174 | OR295448 | OR296383 | OR296391 | OR296403 | |
| China (GD) | KM278016 | — | — | — | — | — | ||
| Pseudolagarobasidium sp. | China | MK790683 | — | — | — | — | — | |
| China | MK790684 | — | — | — | — | — | ||
| China | MK790685 | — | — | — | — | — | ||
| India | KM053237 | — | — | — | — | — | ||
| Thailand | MK589289 | — | — | — | — | — | ||
| Vietnam | KM234009 | — | — | — | — | — | ||
| Pseudolagarobasidium venustum | holotype of P. pallens | Brazil (RS) | MZ649030 | MZ649030 | — | — | — | — |
| Brazil (RS) | MZ649031 | MZ649031 | — | — | — | — | ||
| Brazil (SP) | MZ649033 | — | — | — | — | — | ||
| Carranza 120929 | Costa Rica | OR262150 | OR262150 | — | — | — | — | |
| K.H. Larsson 11363 | Costa Rica | OR262151 | OR262151 | — | — | — | — | |
| K.H. Larsson 10040 | Puerto Rico | OR262152 | OR262152 | — | — | — | — | |
| Radulodon americanus | USA (MN) | JQ070174 | — | — | — | — | — | |
| USA (MT) | JQ070175 | — | — | — | — | — | ||
| Radulodon casearius | China (YN) | MK404494 | — | — | — | — | — | |
| USA (FL) | KY948752 | KY948871 | — | — | KY948943 | — | ||
| Radulodon erikssonii | Pennanen 3794 | Finland | OR262200 | — | — | — | — | OR296426 |
| Pennanen 3886 | Finland | OR262199 | — | — | — | — | — | |
| Norway | KY415963 | KY415963 | KY415964 | KY415971 | — | — | ||
| Sweden | MH864059 | — | — | — | — | — | ||
| Martini (GB 0181279) | Switzerland | OR359377 | OR359377 | — | — | — | — | |
| Radulodon yunnanensis | holotype | China (YN) | OM971916 | OM971936 | — | — | — | OM982705 |
| China (YN) | OM971915 | OM971897 | — | — | — | OM982704 | ||
| China (YN) | OM971917 | OM971898 | — | — | — | OM982706 | ||
| Somion delectans | India | MG719295 | — | — | — | — | — | |
| India | MT126488 | — | — | — | — | — | ||
| USA | MH856070 | — | — | — | — | — | ||
| USA (KY) | MN430947 | — | — | — | — | — | ||
| USA (MD) | HQ728301 | — | — | — | — | — | ||
| USA (MD) | KY948750 | — | — | — | — | — | ||
| CFMR FP-101579-Sp* | USA (MD) | OR262198 | — | — | — | — | — | |
| USA (MI) | KP135301 | KP135287 | — | — | KP134876 | — | ||
| USA (MS) | HQ728299 | — | — | — | — | — | ||
| J. Vlasák (JV 0809/62) | USA (NH) | OR262183 | OR262183 | — | — | — | OR296411 | |
| J. Vlasák Jr (JV 1507/22) | USA (PA) | OR262182 | OR262182 | — | — | — | OR296410 | |
| USA (PA) | HQ728297 | — | — | — | — | — | ||
| USA (PA) | HQ728298 | — | — | — | — | — | ||
| USA (PA) | HQ728300 | HQ729007 | — | — | — | — | ||
| Somion formosanum | ATCC MYA-262*, ex-holotype | Taiwan | JQ070094 | JQ070165 | — | — | OR296396 | OR296423 |
| Somion litschaueri | Austria | HQ728304 | — | — | — | — | — | |
| Austria | HQ728306 | HQ729009 | — | — | — | — | ||
| Austria | UDB0802574 | — | — | — | — | — | ||
| China (BJ) | FJ789779 | — | — | — | — | — | ||
| China | MH425279 | — | — | — | — | — | ||
| China | OM971907 | — | — | — | — | — | ||
| China | OM971912 | — | — | — | — | — | ||
| J. Vlasák (JV 1309/1) | Czech Republic | OR262189 | OR262189 | — | — | — | OR296417 | |
| Czech Republic | HQ728303 | — | — | — | — | — | ||
| Czech Republic | HQ728305 | — | — | — | — | — | ||
| Czech republic | HQ728307 | — | — | — | — | — | ||
| Czech Republic | HQ729014 | HQ729014 | — | — | — | — | ||
| Russia (PRI) | UDB0780498 | — | — | — | — | — | ||
| J. Vlasák (JV 1309/7) | Slovakia | OR262190 | OR262190 | — | — | — | OR296418 | |
| — | MH860539 | — | — | — | — | — | ||
| Somion occarium | epitype | Czech Republic | OR262180 | OR262180 | — | — | — | OR296408 |
| J. Vlasák (JV 1310/23) | Czech Republic | OR262181 | OR262181 | — | — | — | OR296409 | |
| Czech Republic | HQ728294 | HQ729004 | — | — | — | — | ||
| Czech Republic | HQ728295 | HQ729005 | — | — | — | — | ||
| Czech republic | HQ728296 | — | — | — | — | — | ||
| K.H. Larsson 14261 | Sweden | OR262194 | — | — | — | — | — | |
| — | AJ006670 | — | — | — | — | — | ||
| Somion strenuum | holotype | Russia (KHA) | OR262186 | OR262186 | OR295451 | — | OR296394 | OR296414 |
| Dai 3041 | China (LN) | KY415961 | KY415961 | KY415966 | KY415969 | — | — | |
| Miettinen 10546 | China (LN) | OR262164 | OR262164 | — | — | — | — | |
| China (LN) | KY415961 | — | — | — | — | — | ||
| Spirin 6112 | Russia (KHA) | OR262187 | OR262187 | — | — | — | OR296415 | |
| Somion tomsovskyi | J. Vlasák Jr (JV 1209/55) | USA (AZ) | OR236210 | OR236210 | OR295455 | OR296387 | — | OR296413 |
| J. Vlasák Jr (JV 1307/8) | USA (AZ) | OR262184 | OR262184 | — | OR296386 | OR296393 | OR296412 | |
| USA (AZ) | KY948751 | — | — | — | KY948942 | — | ||
| Somion unicolor | France | FJ349625 | — | — | — | — | — | |
| USA (AZ) | HQ728302 | — | — | — | — | — | ||
| USA (GA) | OL142241 | — | — | — | — | — | ||
| USA (LA) | HQ728312 | — | — | — | — | — | ||
| USA (MI) | HQ728311 | — | — | — | — | — | ||
| USA (MO) | HQ728310 | — | — | — | — | — | ||
| J. Vlasák Jr (JV 1304/1) | USA (NJ) | OR262188 | OR262188 | — | — | — | OR296416 | |
| J. Vlasák Jr (JV 1708/10) | USA (NJ) | OR262195 | OR262195 | — | — | OR296397 | OR296424 | |
| USA (VA) | HQ729011 | HQ729011 | — | — | — | — | ||
| USA (WI) | HQ728308 | — | — | — | — | — | ||
| USA (WI) | HQ728309 | — | — | — | — | — | ||
We compiled eight sequence datasets for phylogenetic analysis. Selection was based on ITS and LSU sequence similarity searches for each Cerrenaceae species in GenBank (using BLAST; Altschul et al. 1997) and UNITE (Nilsson et al. 2018) implemented in PlutoF (using BLAST and species hypothesis annotation; Abarenkov et al. 2010). We referred to Justo et al. (2017) when selecting the outgroup (the closest relative Panaceae) for the family-level dataset. For the other datasets (genus-level trees), which were compiled mainly for species delimitation, we used mid-point rooting without an outgroup. Since genetic distances between genera are generally large, including outgroup sequence with a divergent ITS sequence would have decreased the number of homologous (alignable) characters significantly, reducing species resolution.
We aligned the sequences with PRANK v. 170427 (Löytynoja 2021) or the MAFFT online service with E-INS-I (Katoh et al. 2017), each marker individually, and adjusted them manually in PhyDE v. 0.9.7.1 (Müller et al. 2010). We excluded characters from the 6-marker dataset manually when judged as non-homologous. The datasets, with the final alignment length and the number of parsimony informative sites calculated in MEGA v. 7 (Kumar et al. 2016) are as follow: i) a 6-marker dataset of Cerrenaceae (1 091 parsimony informatic characters/5 228 total characters), ii) Cerrena ITS (72/618), iii) Irpiciporus ITS (32/588), iv) Irpiciporus ITS+TEF1 (63/1 604), v) Lividopora ITS (39/604), vi) Pseudolagarobasidium ITS (61/564), vii) Radulodon ITS (11/597), viii) Somion ITS (32/542), ix) Somion ITS+TEF1 (138/1 684), and x) Cystostereaceae ITS (93/708). The 6-marker dataset of the Cerrenaceae contained nrDNA
ITS and LSU, mtSSU, ATP6, TEF1 and RPB1. Two of the markers are mitochondrial (mtSSU and ATP6), and all, except for ITS and LSU, independently evolving. To reduce gaps in the alignment, data within five species were fused so that for Cerrena ‘gilbertsonii’, GenBank OR296399 was used for RPB1 while the rest of the markers were from Vandevender 94-144 (GenBank OR262171, etc.); GenBank KP134874 was used for RPB1 of Cerrena unicolor while the rest were from the collection Larsson (GenBank JN710525, etc.); GenBank KP134876 for RPB1 of Somion delectans while the rest of the markers were from the collection Vlasák Jr. JV 1507/22 (GenBank OR262182, etc.); GenBank KY948942 for RPB1 of Somion tomsovskyi while the rest of the markers were from Vlasak JV 1209-55 (GenBank OR236210, etc.); and GenBank OR296426 for TEF1 of Radulodon erikssonii while the rest were from Hofton 09820 (GenBank KY415963, etc.). In all these cases, the ITS similarity was > 99.5 %. Thus compiled, marker data were missing for 27 % of the maximum 180 marker sequences. At the level of genera, only one marker sequence out of 54 (mtSSU of Acanthodontia) was missing.
Models for the phylogenetic analyses were selected for each marker and dataset by AICc ModelTest-NG v. 0.2.0 (Darriba et al. 2020). We inferred phylogenies with MrBayes v. 3.2.7a (Ronquist et al. 2012) and RAxML-NG v. 1.1.0 (Kozlov et al. 2019). Bootstrap support values for the RAxML maximum likelihood analyses were calculated from 1 000 replicas. MrBayes v. 3.2.7a was run with three parallel runs of 8 chains each for 2–4 million generations, sampling every 10 000 generations. Good convergence (standard deviation of split frequencies < 0.01) was reached in all cases and the standard 25 % burnin was used when compiling the consensus tree. All computations were run at the CSC – IT Centre for Science (Espoo, Finland) computing environment. The alignments, with model information included in their nexus blocks, are available at PlutoF (doi: 10.15156/BIO/2938061).
RESULTS
The 6-marker phylogenetic estimate confirms the Cerrenaceae as a well-supported family (Fig. 3). It resolves three main clades within the family: Somion containing Spongipellis delectans and relatives, Irpiciporus-Radulodon and Cerrena-Pseudolagarobasidium. Individual marker phylogenies mostly confirm this, but TEF1 and RPB1 do not support monophyly of the Irpiciporus-Radulodon clade (Supplementary Figs S1–S5).
Fig. 3.
Bayesian consensus phylogram of the Cerrenaceae based on four nuclear (ITS, nLSU, RPB1, TEF1) and two mitochondrial (mtSSU, ATP6) genetic markers. Decimal support values denote posterior probabilities, while values over 50 % denote bootstrap support. The INSDC accession numbers for each leaf refer to ITS. Leaves with asterisk (*) contain data of several specimens (see Material and Methods). Countries (and states) of origin are denoted with ISO 3166 codes.
How should genera in the family be delimited in the light of this information? Our analysis provides several possible solutions in balancing morphology with phylogenetic information. We have assumed here that phylogenetic distance must be reflected in genus limits. Thus, we consider all clades of equal phylogenetic distance consistently as genera within the family, requiring all clades above a threshold be treated equally when deciding on their generic status. Under this condition, and by maximizing morphological distinctiveness and minimizing nomenclatural change, we have divided the family into seven genera, two of them newly described: Acanthodontia gen. nov., Cerrena, Irpiciporus, Lividopora gen. nov., Pseudolagarobasidium, Radulodon, and Somion (Table 2). ITS-based trees of all the genera (except the monotypic Acanthodontia) are provided in the taxonomy section.
Table 2.
Morphological comparison of accepted genera in the Cerrenaceae.
| Genus | Basidiocarp | Hymenial surface | Hyphal system | Cystidia | Spores | Other |
|---|---|---|---|---|---|---|
| Acanthodontia | Effused-reflexed, whitish | Regular long spines | Dimitic but dominated by generatives, gen.hyphae slightly thick-walled, uniform, neatly arranged | Tramal cystidia slightly thick-walled, bend into hymenium | Slightly thick- walled, with guttula | Subhymenium well developed |
| Cerrena | Effused to reflexed, whitish to brown-gray | Regularly poroid to irpicoid | Dimitic | Hymenial thin- walled, staining cystidia | Thin-walled, no guttula | — |
| Lividopora | Effused, red to brown to gray | Regularly poroid, small-pored | Dimitic | 1) Encrusted skeletocystidia, 2) hymenial thin-walled stained cystidia | Thin-walled, no guttula | Clamps absent |
| Pseudolagarobasidium | Effused, whitish tobrownish-grayish, thin | Hydnoid with short blunt teeth to irpicoid | Monomitic & microbinding hyphae | 1) Tramal cystidia slightly thin-walled, bend into hymenium, 2) hymenial thin-walled, staining cystidia | Thin-walled, no guttula | — |
| Radulodon | Effused, whitish | Regular spines | Monomitic, messy, hyphae thin- to slightly thick-walled | Hymenial cystidia, thin-walled | Slightly thick- walled, with guttula | — |
| Irpiciporus | Effused-reflexed to reflexed, relatively thin, whitish | Irpicoid to sinuous pores | Monomitic, neat, hyphae slightly thick-walled, uniform | None | Slightly thick- walled, with guttula | Subhymenium almost nonexistent; basidia long (> 20 μm) |
| Somion | Reflexed, thick, context duplex, whitish | Pores regular to sinuous | Monomitic, neat, with a mix of thin-and thick-walled hyphae | None | Thick-walled, with guttula | Subhymenial cells differentiated; basidia short (mostly <x 20 μm) |
Cerrena-Pseudolagarobasidium clade
The 6-marker phylogeny supports dividing the Cerrena- Pseudolagarobasidium clade into three to four parts: Cerrena unicolor and relatives, Cerrena zonata and relatives, Rigidoporus vinctus and relatives, and Pseudolagarobasidium (Fig. 3). When analyzed individually (Supplementary Figs S1–S5), only RPB1 (Supplementary Fig. S4) produces a similar topology as the 6-marker dataset (supporting a clade containing C. unicolor and C. zonata). However, also the ITS+LSU and ATP6 datasets support division into the above-mentioned four subclades, albeit with a different branching order (Supplementary Figs S1, S3). The rest of the markers, mtSSU and TEF1, fail to recover the four clades (Supplementary Figs S2, S5). None of the individual marker phylogenies contradicts the 6-marker phylogeny, and differences are due to the lack of support for most nodes.
The resulting phylogeny leaves us with four well-supported options in delimiting genera in the Cerrena-Pseudolagarobasidium clade. First, phylogenetically perhaps the simplest solution would be to include all species in this clade in one genus (Cerrena). All the species in this clade share some morphological characters: dimitic hyphal structure, thin-walled, ellipsoid, middle-sized spores, and thin-walled hymenial cystidia (“gloeocystidia”). They are all aggressive wood-rotters, and there are tree pathogens in all the subclades. Species in the clade grow fast on malt agar and are enzymatically active (Nobles 1948, Westhuizen 1963, Setliff 1972a, Maekawa 2002, Wood & Ginns 2006). However, morphological differences of basidiocarps between the extremes are still quite significant (see below), and one large genus would be at odds with the current traditions of defining polypore and corticioid genera morphologically.
Second, the genus could be divided into hydnoid and nearmonomitic Pseudolagarobasidium on one hand, and dimitic polypores of Cerrena and Rigidoporus vinctus on the other. Thus delimited, Cerrena would be better morphologically defined, but still quite heterogenous. This option would induce minimal name changes.
The third option is to divide the clade into three genera: hydnoid, effused, nearly monomitic Pseudolagarobasidium, dimitic Cerrena with clamped hyphae and irregular/dentate pores (including C. unicolor and C. zonata subclades), and dimitic but simple septate Rigidoporus vinctus coll. with encrusted skeletocystidia and regular, small pores. Thus defined, the three groups are distinct and easy to separate from each other. We consider this the best solution currently and describe here the genus Lividopora for the R. vinctus subclade.
Lastly, the fourth option would be to divide the clade into four genera: Cerrena sensu stricto (C. unicolor and relatives), a new genus for C. zonata and relatives, Lividopora, and Pseudolagarobasidium. This option, too, has merits. Morphologically, there are some differences between the C. unicolor and C. zonata clades: more pronounced pigmentation in Cerrena sensu stricto, duplex context, more distinct gloeocystidia in the C. zonata subclade, and subtle differences in hyphal structure. However, these characters (except duplex context) are subject to gradation. In our experience, they are not as informative phylogenetically as, for instance, the presence of skeletocystidia or type of septation, which are more reliable and easier to interpret among polypores. Furthermore, as shown under taxonomy part of Cerrena, diversity in the C. zonata clade exceeds the currently described species and our material. Hence, a genus description for this clade would be outdated from the start – a clear argument for sticking to larger genera. Finally, if the Cerrena-Pseudolagarobasidium clade would be divided into four genera, and we would define all similarly distant clades in the family as separate genera, the Somion clade (Spongipellis delectans and relatives) would also be split into two, morphologically very similar sister genera, which we think is unnecessary.
Radulodon-Irpiciporus clade
The Radulodon-Irpiciporus clade is divided phylogenetically into three subclades: Radulodon sensu typi, R. cirrhatinus, and Irpiciporus. This clade is morphologically fairly homogenous: basidiocarps are light-coloured, hydnoid or irpicoid, (nearly) monomitic with clamps, hymenial cells relatively large, and spores slightly thick-walled. Placing these species in one genus would be a good option from this perspective. Phylogenetically the three parts are distant, however. Considering our genus concepts in the Cerrena-Pseudolagarobasidium clade, i.e., division of that clade into several genera, the three parts of the Radulodon-Irpiciporus clade must be considered separate genera. We describe here a monotypic genus Acanthodontia for Radulodon cirrhatinus. Despite similarities, there are some differences between the genera: Acanthodontia and Radulodon are fully hydnoid whereas Irpiciporus are irpicoid to poroid; cystidia and rare skeletal hyphae are found in Acanthodontia and Radulodon. The latter two differ for instance in their hyphal structure and nature of skeletal hyphae (Table 2).
Somion clade
Spongipellis delectans and its relatives form a distinct clade and clearly merit recognition at the genus level. They are monomitic polypores with clamps and loose structure, thick-walled spores and big, light-coloured caps, somewhat similar to Spongipellis sensu stricto, which belongs to a different family, Meripilaceae (Spirin et al. 2022). Wang & Dai (2022) reached similar conclusion about this clade’s generic status and described Pseudospongipellis. We adopt the genus name Somion as the correct name for this clade. Somion delectans and its European sibling S. occarium are phylogenetically distinct from the rest of the species, but since morphological differences are small, we see no reason to split this genus further.
Taxonomy
Acanthodontia Miettinen & Spirin, gen. nov. MycoBank MB 849641.
Type species: Acanthodontia cirrhatina (Hjortstam & Spooner) Miettinen & Spirin
Etymology: Derived from ἄκανθος (Greek, noun), thorn, and -odon derived from the Greek word for sharp teeth, ὀδοντιάω.
Pileate, sessile, white to cream basidiocarps with long spines underneath. Hyphal system dimitic with clamps in all septa of generative hyphae, but skeletal hyphae found in context and subiculum only, otherwise monomitic and dominated by slightly thick-walled generative hyphae, in trama subparallel. Long, slightly thick-walled sack-like cystidia embedded in trama and hymenium. Basidiospores ellipsoid, mid-sized, smooth, slightly thick-walled, with a large guttule, cyanophilous.
Acanthodontia cirrhatina (Hjortstam & Spooner) Miettinen & Spirin, comb. nov. MycoBank MB 849642. Figs 2, 4.
Fig. 4.
Microscopic structures of Acanthodontia cirrhatina (Miettinen 13717). Subicular skeletal and generative hyphae, trama and hymenium, cystidia, and spores.
Basionym: Radulodon cirrhatinus Hjortstam & Spooner, Kew Bull. 45: 312, 1990.
Typus: Malaysia, Sabah, Danum Valley, on a fallen log, 30 Nov. 1985, Spooner 295* (holotype K(M) 62575, studied).
Basidiocarp resupinate to half-resupinate, caps white, with a rough but hairless upper surface, projecting up to 2 cm; resupinate patches up to 10 cm wide. Hymenophore consists of regular conical spines, 4–15 mm long and 2 per mm, white to cream when fresh with reddish brownish tints upon drying. Subiculum white, uniform, 0.5–1 mm thick, cap context 1–2 mm thick, up to 7 mm at the base. Margin distinct, often with a 1–2 mm wide zone of sterile subiculum visible.
Hyphal system dimitic, but skeletal hyphae rare and concentrated in cap context, clamps present. Generative hyphae homogenous, slightly thick-walled, (2.2–)2.8–4.4(– 5.8) μm diam in subiculum, (2.4–)3.0–4.2(–5.3) μm in trama. Subiculum structure similar to context, but skeletal hyphae fewer. Context a loose, interwoven structure with segments of skeletal hyphae here and there, (2.0–)2.4–3.1(–3.9) μm diam. Tramal hyphae subparallel, structure rather loose; a distinct subhymenial layer consisting of strongly interwoven hyphae, 20–50 μm thick. Cystidia clavate, tramal or rarely subhymenial in origin, bending into hymenium, projecting up to 10 μm, slightly thick-walled basally when young, thickwalled and cyanophilous when old, often with constrictions when old, occasionally tapering but always blunt, sometimes with a deep root, 38–135 × 9–17 μm (up to 70 μm long without the root). Similar, swollen cells embedded in context. Basidia clavate, some constricted, (14–) 16–26 × 5.5–6.8 μm, with 4 sterigmata. Basidiospores ellipsoid, slightly thick-walled (walls 0.2–0.3 μm), uniguttulate, slightly to distinctly cyanophilous, 4.0–5.1(–5.2) × (3.4–)3.5–4.2(–4.3) μm, L = 4.69 μm, W = 3.79 μm, Q = 1.21–1.26. μm, Q = 1.21–1.26.
Distribution and ecology: The two known finds are from lowland rainforests in insular Southeast Asia, viz. Borneo and Sumatra.
Notes: Acanthodontia cirrhatina is easy to identify by its long spines, effused-reflexed basidiocarps and tramal cystidia that penetrate the hymenium. This monotypic genus is morphologically quite similar to its sister taxon, Irpiciporus. The phylogenetic distance to Irpiciporus is sufficiently large and consistent throughout genetic markers that A. cirrhatina should warrant its own genus. They share very similar cyanophilous spores, hymenium, and the tramal construction of loosely arranged, subparallel hyphae. Basidiocarp habit is also quite similar, but the A. cirrhatina hymenophore consists of regular, slender, conical spines, whereas Irpiciporus spp. have poroid to irpicoid hymenophore. Microscopically, skeletal hyphae and cystidia of Acanthodontia are lacking in basidiocarps of Irpiciporus. Subhymenial layer appears more visible and thicker than in Irpiciporus spp.
The next closest kin, Radulodon spp., form fully effused, thinner basidiocarps. Microscopically, the interwoven, messy-looking hyphal structure is different, and skeletal hyphae are much narrower. Cystidia are a shared character between the two genera, and along with the hydnoid hymenophore the reason why A. cirrhatina was described in Radulodon.
Nakasone (2001) studied the type specimen and accurately described skeletal hyphae; later she considered the species monomitic with sclerified segments of generative hyphae (Nakasone & Ortiz-Santana 2022). In our view, those segments and hyphae should be called skeletal hyphae. They are found in old cap context, and do not dominate structure anywhere. Another slightly younger specimen (Miettinen 13717) has so few skeletal hyphae that we found them only after specifically looking for them in context. Vegetative mycelial mats associated with the latter specimen are dominated by narrow skeletal hyphae with occasional thin-walled branches that branch at right angles, reminiscent of (but not fully similar to) the microbinding hyphae documented by David (1969) in Irpiciporus pachyodon.
Cerrena Gray, A natural arrangement of British plants 1: 649. 1821.
Type species: Boletus unicolor Bull.
Pileate to resupinate polypores with cream, brownish to grey basidiocarps with a cottony context. Pores mid-sized, irregular in old specimens, in some species irregular already when young. Hyphal system dimitic with clamps; intermediary hyphae and branching skeletal hyphae may be present. Hyphae CB(+), IKI-, KOH-, CRB lilac. Hymenial, thin-walled cystidia with a stained inclusion (“gloeocystidia”) present, though may be absent in young specimens. Basidiospores ellipsoid, mid-sized, with thin or distinct walls. Aggressive white rotters.
Notes: Cerrena can remind of other polypore genera with pilei and dimitic hyphal structure, such as Antrodiella, Funalia, and Trametes. However, thin-walled hymenial cystidia are not present in Funalia or Trametes, and the latter genus is distinctly trimitic. Furthermore, ellipsoid spores are rare in Trametes and not known from Funalia. In Antrodiella sensu stricto, thin-walled hymenial cystidia (“gloeocystidia”) may be present in older basidiocarps, but spore and basidial size is consistently smaller and so is mostly pore size.
Two subclades can be distinguished in Cerrena as we define it (Fig. 3): the Cerrena unicolor complex (incl. C. cystidiata and C. ‘gilbertsonii’) with brownish-greyish basidiocarps, and the C. zonata complex (incl. C. albocinnamomea and C. multipileata) with light-colored basidiocarps. The latter complex was placed in Antrodiella (Dai & Niemelä 1997, Nuñez & Ryvarden 2001, Ryvarden 2015), until Yuan (2014) moved some of them to Cerrena solely on phylogenetic grounds. We considered two separate genera for these clades, but we decided against splitting. Microscopically, the larger Cerrena is quite homogenous. Irregular pores are also shared by all species. Colour difference of basidiocarps is also not a clear separating character: C. albocinnamomea, as the name implies, turns brownish when old, and young specimens of C. unicolor are white. ITS data (Fig. 5) show that more species than described here are present, forming a third clade, but we have no information about their morphology. All these arguments support a larger genus. Duplex context is a unique character for the C. unicolor clade within the genus.
Fig. 5.
Bayesian consensus phylogram of Cerrena spp. based on ITS sequences. For each leaf, the GenBank accession number, the species name (as available), and the ISO 3166 country code of the country of origin are shown.
When Gray (1821: 649) described Cerrena, he accepted only one species, Cerrena cinerea (Pers.) Gray. He mentioned Sistotrema cinereum Pers. and Boletus unicolor Sowerby (= B. unicolor Bull.) as synonyms of the aforementioned species. Both are available for typification of the genus (ICN Shenzhen art. 10.2). The lectotypification is traditionally assigned to Murrill (1903: 91), who chose Daedalea unicolor (Bull.) Fr. as the genus type. Later he mentioned S. cinereum as the type (Murrill 1908). Recent changes in the International Code of Nomenclature suppress typifications by Murrill (art. 10.5, 10.7). The next oldest typification we could trace is by Bondartsev (1953: 45), who selected “Cerrena unicolor (Bull.) Murrill” as the type species.
Fries (1821, 1828) considered Sistotrema cinereum Pers. a synonym of Daedalea unicolor (Bull.) Fr. The latter name is thus sanctioned. Fries also accepted Daedalea cinerea as a separate species, but with a different identity than S. cinereum, even though he considers part of Persoon’s concept of S. cinereum to belong to his D. cinerea. Formally, the identity of D. cinerea Fr. is not relevant for the typification of Cerrena. To conclude, the correct, sanctioned name for the type species of Cerrena is C. unicolor (Bull.) Murrill.
The relationship of Cerrena and Trametes has been a subject of discussion due to their morphological similarity (Ryvarden 1991). The two genera are not closely related as DNA phylogenies reveal. Bipolar mating system (Westhuizen 1963, Nobles 1965), broad ellipsoid spore shape (rare in Trametes), and less clearly trimitic hyphal system are some of the characters that separate Cerrena from Trametes.
The hyphal system in Cerrena unicolor does not readily fit into terminology of hyphal system types. Gilbertson & Ryvarden (1986) and Bernicchia (2005), for instance, call it trimitic and Niemelä (2005) di-trimitic. The context and lower trama consist of long, straight, wide skeletal hyphae intermixed with generative and narrower, winding, and occasionally branching skeletal hyphae (“binding hyphae”). The structure appears trimitic initially, but it is not as distinct as in Trametes, where skeletal and binding hyphae can usually be separated with ease. In the case of Cerrena, the distinction between the two “types” is not clear-cut, and intermediary hyphae occur – sometimes a single hypha may turn from skeletal to “binding”. In his detailed study Westhuizen (1963) finds two types of hyphae but points out that clamps are found on the thick-walled hyphae. He goes on to define this species monomitic. We have also observed that thick-walled clamps at the start/end of skeletal segments are rather common (not so in Trametes). In our view, the hyphal structure in C. unicolor is best described as dimitic, with some intermediary hyphae and branching of skeletal hyphae.
Cerrena albocinnamomea (Y.C. Dai & Niemelä) H.S. Yuan, Mycol. Progr. 13: 362. 2013. [2014]. Fig. 1.
Basionym: Antrodiella albocinnamomea Y.C. Dai & Niemelä, Mycotaxon 64: 70. 1997.
Synonym: Cerrena aurantiopora J.S. Lee & Y.W. Lim. Mycologia 102: 212. 2010.
Typus: China, Jilin, Antu, Changbaishan, on stump of Acer, 5 Sep. 1993, Dai 1063 (holotype of Antrodiella albocinnamomea H).
Notes: For description, see Dai & Niemelä (1997). This temperate East Asian species with resupinate basidiomes can be mistaken for Antrodiella. The cottony subiculum and sterile, even fimbriate margin, relatively large size of basidiomes and a bit larger spore size separate it from Antrodiella sensu stricto. The hymenial cystidia, although present, can be rare and difficult to find.
Cerrena cystidiata Rajchenb. & Meijer, Mycotaxon 38: 176. 1990.
Typus: Brazil, Paraná, São José dos Pinhais, Reserva Biológica Cambuí, dead and standing Sebastia connersoniana, 22 May 1988, de Meijer 1169 (holotype BAFC 31626).
Notes: Westphalen & Motato-Vásquez (2022) provide a sequence they have labelled as C. cystidiata from the south of Brazil, where the type was collected. They do not mention if they have compared it with the type, nor do they provide a description. The sequence is unique and closely related to C. ‘gilbertsonii’ and C. unicolor (Fig. 5). It is not out of the question that C. ‘gilbertsonii’ sensu Ryvarden could be found in Brazil as well, so comparison with the type is needed to confirm if the Brazilian specimen or C. ‘gilberstonii’ actually belong to this species. Looking at the protologue, we cannot readily point to any clear differences to separate C. cystidiata from C. ‘gilbertsonii’.
Cerrena ‘gilbertsonii’ Ryvarden, nom. prov. Fig. 6.
Fig. 6.
Spores of Cerrena gilbertsonii and C. unicolor. Other hyphal structures, gloeocystidia, swollen skeletal hyphal ends, context skeletal hyphae, belong to Cerrena unicolor (Uotila 47588).
Typus: Mexico, Sonora, Alamos area, Rio Cuchujaqui, El Guyabo crossing, on Croton cf. niveus, 14 Mar. 1994, Vandevender 94-144 (holotype ARIZ, isotype O* studied).
Notes: When Ryvarden (2012) first described this species, he omitted holotype herbarium information, making the description invalid from a nomenclatural perspective (ICN Art. 40.7). In Ryvarden (2015) he amended his description with the holotype information to validate the name, but without supplying a digital identifier, which is required since 2013 (ICN Art. F.5.1). Thus, the name remains invalid. Since the identity of C. cystidiata vs. C. ‘gilberstonii’ is unclear, we refrain from validating the name, but use it as nomen provisorum to denote a good species separate from C. unicolor.
Cerrena ‘gilbertsonii’ is very close to C. unicolor phylogenetically and morphologically. As Ryvarden (2012) describes, usually its basidiocarps are smaller and thinner and more hydnoid than those of C. unicolor. However, variation in C. unicolor is considerable and equally hydnoid specimens are found in the latter species as well. Its basidiocarps may also be small and thin. Judging by the few samples we have seen, the upper surface is consistently brown and hairs shorter than in C. unicolor, whose caps are initially much lighter in colour and never as evenly brown. Ryvarden (2015) mentions the presence of gloeocystidia as a separating character. Gloeocystidia are also found in C. unicolor, and they are notoriously unreliable as a character for identification, being sometimes absent and highly dependent on basidiocarp age. Spore shape and size, however, seem to be reliable microscopic characters: spores in C. unicolor are narrower (on average about 3 μm, Q > 1.5) than in C. ‘gilbertsonii’ (width about 3.5 μm, Q < 1.5; Table 3, Fig. 6).
Cerrena multipileata (C.L. Leite & J.E. Wright) Miettinen, comb. nov. MycoBank MB 849643.
Basionym: Antrodiella multipileata C.L. Leite & J.E. Wright,
Mycotaxon 41: 167. 1991.
Typus: Brazil, Santa Catarina, Florianópolis, Morro da Lagoa da Conceicão, 27 Jul. 1998, Leite & Furlani 251 (holotype FLOR 10633, studied).
Notes: This species is an American counterpart of C. zonata from Asia. We have not been able to find morphological differences between the two species, but it should be said we have limited material of C. multipileata at hand. Our sequenced specimens of A. multipileata are not from the type area in South Brazil but rather from Central America. ITS sequences differ slightly (7 bp, 1.3 %) between the two species. For the time being, we retain C. multipileata as a distinct, geographically defined species.
Cerrena unicolor (Bull.) Murrill, North American Flora 9(2): 124. 1908. Figs 1, 6.
Basionym: Boletus unicolor Bull., Herbier de la France 9: t. 408. 1789; sanctioned as Daedalea unicolor (Bull.) Fr., Syst. Mycol. 1: 336. 1821.
Synonyms: Polystictus prosector Lloyd, Mycological Writings 7(67): 1147. 1922. See MycoBank for additional synonyms.
Typus: Lectotype of Daedalea unicolor designated here, plate 408 of Bulliard (1789) cited in the sanctioning work (Fries 1821), MBT 10014555.
Notes: Cerrena unicolor is a variable species, abundant in the boreal zone and rather frequent in the temperate zone. For a description, see Ryvarden & Melo (2016).
It would appear that the northern specimens are on average more robust and less irpicoid than the southern ones. ITS variation (Fig. 5) does not suggest more than one species in Eurasia. The same species is also found in North America. Nuñez & Ryvarden (2001) list C. cystidiata for East Asia, though it is unclear if their description is based on Asian material (the species was described from South America). Our sequenced specimen from Kyrgyzstan fits their description yet it represents C. unicolor. As mentioned under ‘C. gilbertsonii’, gloeocystidia are not a reliable character for separating species in this complex. The type of Polystictus prosector from China is a similar, thin, small-pored specimen with many gloeocystidia, and for the time being we consider it a synonym of C. unicolor.
We have not been able to locate a proper typification for the species Daedalea unicolor. Ryvarden (1991) selected a neotype (his “lectotype” from 1850 must be considered a neotype), but a neotype should only be selected if no original material is in existence (ICN art. 9.8). The illustrations cited in the protologue and the sanctioning work are part of such original material and, in the absences of specimens, must be used for lectotypification (art. 9.4). Thus, we select here the plate 408 of Bulliard (1789) cited in the sanctioning work (Fries 1821) as the lectotype of D. unicolor (Bull.) Fr. The current species concept of C. unicolor in Europe and the lectotype illustrations are clear enough that we see no need for an epitype.
Murrill (1903) did not accept Cerrena as a good genus, and therefore his 1903 combination of C. unicolor is invalid (ICN art. 33.1). In Murrill (1908: 124) he does accept Cerrena and this should be considered the correct publication for the valid combination.
Cerrena zonata (Berk) H.S. Yuan, Mycol. Progr. 13: 363. 2013. [2014]. Figs 1, 7.
Fig. 7.
Cerrena zonata (Miettinen 9773). Context hyphae, tube trama and hymenium, hymenial cystidia and spores.
Basionym: Irpex zonatus Berk., Hook. J. Bot. 6: 168, 1854.
Synonyms: Irpex consors Berk., J. Linn. Soc. Bot. 16: 51. 1877.
Cerrena consors (Berk.) K.S. Ko & H.S. Jung, FEMS Microbiol. Lett. 170: 185. 1999.
Irpiciporus consors (Berk.) Murrill, Mycologia 1: 166. 1909.
Irpiciporus japonicus Murrill, Mycologia 1: 166. 1909.
Typus: Nepal, Ilam district, 8 Nov. 1848, Hooker (lectotype of Irpex zonatus designated here K(M) 147643, MBT 10014532, studied).
Notes: This species is easy to recognize by its pilei with an irpicoid hymenophore combined with dimitic structure with clamps and cystidia. Ryvarden (1992) provided a description and compiled a comprehensive treatise on the nomenclature. He studied types of I. zonatus and eight other species described from Australia, Indian Himalayas, Japan, and New Zealand. He found them to represent the same taxon, for which the oldest name is I. zonatus. Ryvarden gives a good description of the species, and we trust his concept of the species. Our ITS dataset (Fig. 5) contains sequences of this species among others from New Zealand, Australia, Sumatra, Vietnam, Bhutan, Japan, and Chinese Himalayas, and these specimens show little ITS variation, supporting the conclusion about one wide-spread species, excluding Neotropics, where the sister species C. multizonata is found.
In his otherwise comprehensive paper, Ryvarden (1992) did not lectotypify I. zonatus. Also Maas Geesteranus (1974: 503) left the matter open, and in his type studies Ryvarden (1977) does not deal with the species. Berkeley’s species description seems to mention two specimens, one from Sikkim and another from East Nepal collected by Hooker: “Sikkim; East Nepal. November 8. (Dr. Hooker.)” (Berkeley 1854). There are two specimens marked as syntypes in Kew, one from Sikkim, another from East Nepal, collected on 8 November. The envelope from Sikkim contains only remnants of context glued to paper, but the latter is a good-sized specimen. We designate here the specimen “East Nepal, November 8”, K(M) 147643 as the lectotype of Irpex zonatus. The lectotype is sterile and mouldy, but recognizable. According to Hooker’s travel journal, it was collected between “Jummanoo” [Jamuna?] and “Sakkiazung” [Sakhejung?] villages, in today’s Ilam district of Nepal (Hooker 1854).
Irpiciporus Murrill, Bull. Torrey Bot. Club 32: 471. 1905.
Basidiocarps annual or biennial, sessile, effused-reflexed or completely resupinate, light-coloured, watery in fresh condition, rather tough after drying. Context duplex, with softer upper and more compact lower layer. Pores range from regular angular when young, splitting to irregular pores in some species, to incomplete, becoming dentate or spathulate in others. Hyphal structure monomitic, loose, homogenous, hyphae clamped and slightly cyanophilous, thin- to thick-walled, subparallel in trama. Basidia long-clavate, 20–45 × 5–8 μm, four-spored, with guttulate contents. Basidiospores broadly ellipsoid to subglobose, slightly thick-walled (wall 0.2–0.3 μm thick), with a central oil-drop, slightly to distinctly cyanophilous. Causes a white rot of living and dead dicot trees.
Genus type: Irpex mollis Berk. & M.A. Curtis
Notes: Irpiciporus spp. have completely monomitic basidiocarps, but David (1969) has shown that when cultured I. pachyodon produces microbinding hyphae similar to Pseudolagarobasidium and Radulodon. She does not report similar hyphae for Somion occarium (as “Spongipellis delectans”).
We accept here five Irpiciporus species, but from available DNA data it is evident that at least one additional species also belongs to the core Irpiciporus (Fig. 8). Zhao et al. (2017) published a sequence under the name Tyromyces xuchilensis from Ecuador (Ryvarden 44669, studied, GenBank KX161650). This sequence belongs to Irpiciporus in the close vicinity of I. sinuosus – but not to T. xuchilensis (see Excluded taxa). It might belong to Tyromyces irpiceus, which is possibly a species of Irpiciporus as indicated by Corner (1989) himself. Irpiciporus sinuosus and the Ecuadorian material have regularly poroid hymenophore unlike the other species, which are truer to the genus name in having an irpicoid hymenophore of splitting pores. Otherwise, basidiocarp configuration, colouration, and micromorphology are very similar among all the species in the genus.
Fig. 8.
Bayesian consensus phylograms of Irpiciporus spp. based on ITS and ITS+ TEF1 datasets. Countries (and states) of origin are denoted with ISO 3166 codes.
Nakasone & Ortiz-Santana (2022) combined three hydnoid species in the genus. We accept one of those species (Irpiciporus revolubilis) in Irpiciporus, but we show here that Irpiciporus africanus (Ipulet & Ryvarden) Nakasone belongs to Hypochnicium rather than to the Cerrenaceae. We treat the third species (I. decolorans) as insufficiently known (see Excluded taxa).
After describing the genus, Murrill used Irpiciporus as a replacement for Irpex. From Irpiciporus sensu Murrill, only the type species is in the Cerrenaceae, and the rest of the species are a variable set of unrelated irpicoid polypores (Donk 1974). All names combined to Irpiciporus are commented either as recognized species or synonyms or under Excluded taxa.
Irpiciporus branchiformis Miettinen & Spirin, sp. nov. MycoBank MB 849644. Fig. 9.
Fig. 9.
Irpiciporus microscopic structures. Tube trama, hymenium and spores of I. branchiformis (holotype), and spores of I. mollis (Vlasák, JV 0808/45), I. pachyodon (Vlasák, JV 9311/1) and I. revolubilis (holotype).
Typus: Tanzania, Tanga, Lushoto, Mazumbai Forest Res., -4.8075° : 38.5032° ± 300 m, alt. 1 500–1 600 m, lower montane rainforest, fallen log of Ocotea usambarensis, 17 Apr. 1991, Saarimäki 869 (holotype H 7200355).
Etymology: Branchiformis (Lat., adj.), reminiscent of fish gills, in reference to the irpicoid caps of the species.
Basidiocarps annual or biennial, sessile, pilei projecting up to 3 cm. Upper surface pubescent, azonate, cream coloured. Edge of pileus sharp, fertile, concolourous with pileal surface. Hymenial surface more or less concave, cream coloured to pale ochraceous; pores incomplete, shallow, present only in marginal areas, 2–3 per mm, quickly becoming dentate to spathulate and finally transforming to flattened, sharp-pointed spines, 2–3 per mm. Section: context cream coloured, soft, indistinctly fibrillose, up to 0.5 mm thick; hymenial layer soft, concolourous or slightly paler than hymenial surface, up to 0.7 cm thick.
Hyphal structure monomitic, all septa with clamp connections. Context hyphae slightly thick-walled, interwoven to subparallel, (3.0–)3.8–4.4(–5.3) μm diam. Tramal hyphae thin- to slightly thick-walled, subparallel, (2.9–)3.1–4.1(–4.6) μm diam. Subhymenial hyphae not differentiated from tramal ones. Basidiospores slightly thick-walled, subglobose to more rarely broadly ellipsoid, (4.4–)4.7–6.0(–6.2) × 4.0–5.2(–5.3) μm, L = 5.3 μm, W = 4.67 μm, Q = 1.11–1.16.
Distribution and ecology: The species is so far known only from two localities in East Africa (Tanzania), inhabiting decorticated wood of angiosperms.
Notes: Irpiciporus branchiformis differs from two other irpicoid species of the genus (I. mollis and I. pachyodon) in having fragile, thinner basidiocarps, more densely arranged pores/spines, and smaller basidiospores (Table 3).
Table 3.
Spore measurements of studied specimens of the Cerrenaceae.
| Species / specimen | Length | L | Width | W | Q | n |
|---|---|---|---|---|---|---|
| Acanthodontia cirrhatina | 4.0–5.1(–5.2) | 4.69 | (3.4–)3.5–4.2(–4.3) | 3.79 | 1.24 | 65/2 |
| holotype | (4.0–)4.2–4.9(–5.0) | 4.48 | (3.4–)3.5–4.1 | 3.71 | 1.21 | 30 |
| Miettinen 13717 | (4.2–)4.6–5.2 | 4.86 | 3.4–4.2(–4.3) | 3.87 | 1.26 | 35 |
| Cerrena gilbertsonii | (4.5–)4.7–5.4(–5.6) | 5,00 | (3.2–)3.3–4.0(–4.7) | 3.68 | 1.36 | 64/2 |
| isotype | 4.5–5.4 | 4.94 | 3.2–3.8(–3.9) | 3.52 | 1.40 | 34 |
| Vlasák (JV 1609/29) | (4.6–)4.7–5.6 | 5.05 | (3.5–)3.6–4.1(–4.7) | 3.87 | 1.31 | 30 |
| Cerrena multipileata | (3.5–)3.7–5.0(–5.4) | 4.16 | (2.4–)2.5–3.1(–4.4) | 2.79 | 1.49 | 93/3 |
| de Meijer 2623 | (3.9–)4.0–5.2(–5.4) | 4.49 | (2.5–)2.7–3.2 | 2.88 | 1.56 | 30 |
| Ryvarden 43881 | (3.6–)3.7–4.7 | 4.11 | 2.4–3.1(–4.4) | 2.76 | 1.49 | 32 |
| Vlasák (JV 1407/63) | 3.5–4.5(–5.0) | 3.90 | 2.4–3.0 | 2.73 | 1.43 | 31 |
| Cerrena unicolor | (3.9–)4.2–5.6(–6.2) | 4.86 | (2.5–)2.6–3.3(–3.8) | 2.93 | 1.66 | 150/5 |
| Miettinen 16729 | (4.4–)4.6–5.2(–5.5) | 4.83 | (2.6–)2.7–3.2 | 2.97 | 1.63 | 30 |
| Niemelä 30 Jun. 1970 | 4.0–5.3(–5.4) | 4.83 | 2.5–3.1(–3.2) | 2.84 | 1.70 | 30 |
| Niemelä 5352 | (3.9–)4.2–5.3(–5.5) | 4.80 | 2.5–3.0 | 2.74 | 1.75 | 30 |
| Niemelä 6098 | 4.1–6.0(–6.2) | 4.82 | 2.6–3.3(–3.4) | 2.90 | 1.66 | 30 |
| Uotila 47588 | (4.2–)4.4–5.8(–6.2) | 5.03 | (2.8–)2.9–3.7(–3.8) | 3.19 | 1.58 | 30 |
| Cerrena zonata | (3.7–)4.0–5.5(–6.4) | 4.66 | (2.5–)2.6–3.4(–3.6) | 2.95 | 1.58 | 103/3 |
| Gates s.n. | (4.0–)4.2–5.2(–5.5) | 4.62 | 2.6–3.6 | 2.93 | 1.58 | 30 |
| Miettinen 13798 | 3.7–4.7(–4.8) | 4.24 | (2.5–)2.6–3.2 | 2.86 | 1.48 | 33 |
| Miettinen 9773 | 4.3–5.7(–6.4) | 5.04 | 2.8–3.4(–3.5) | 3.05 | 1.65 | 40 |
| Irpiciporus branchiformis | (4.4–)4.7–6.0(–6.2) | 5.30 | 4.0–5.2(–5.3) | 4.67 | 1.14 | 62/2 |
| holotype | (4.4–)4.6–5.7(–5.8) | 5.17 | 4.0–5.1(–5.2) | 4.65 | 1.11 | 32 |
| Niemelä 5937 | (4.6–)4.8–6.1(–6.2) | 5.43 | (4.0–)4.1–5.2(–5.3) | 4.69 | 1.16 | 30 |
| Irpiciporus mollis | (4.8–)5.1–6.2(–6.3) | 5.45 | (4.0–)4.3–5.3(–6.0) | 4.84 | 1.13 | 121/4 |
| lectotype | 5.1–6.2(–6.3) | 5.60 | (4.2–)4.3–5.6(–6.0) | 4.97 | 1.13 | 30 |
| Vlasák (JV 0108/115) | (5.0–)5.2–6.0(–6.2) | 5.54 | (4.3–)4.4–5.2 | 4.87 | 1.14 | 30 |
| Vlasák (JV 0709/174) | (4.8–)5.0–5.9(–6.1) | 5.34 | (4.2–)4.3–5.2(–5.3) | 4.72 | 1.13 | 30 |
| Vlasák (JV 0808/45) | (5.0–)5.1–5.8(–5.9) | 5.34 | (4.0–)4.2–5.3(–5.5) | 4.80 | 1.11 | 31 |
| Irpiciporus pachyodon | (5.2–)5.5–6.5(–7.4) | 6.02 | (4.2–)4.5–5.6(–6.4) | 5.09 | 1.18 | 122/4 |
| Heilmann-Clausen 07–286 | (5.4–)5.5–6.3(–6.5) | 5.87 | (4.3–)4.4–5.3(–5.6) | 4.94 | 1.19 | 30 |
| Melo 327 | 5.4–6.8(–6.9) | 6.02 | (4.7–)4.8–5.6(–6.1) | 5.21 | 1.15 | 30 |
| Spirin 13785 | (5.2–)5.3–6.3(–6.8) | 6,00 | (4.2–)4.4–5.4(–5.6) | 4.94 | 1.22 | 30 |
| Vlasák (JV 9311/1) | (5.6–)5.8–7.2(–7.4) | 6.17 | (4.6–)4.8–5.7(–6.4) | 5.25 | 1.18 | 32 |
| Lividopora armeniaca | (3.7–)3.8–4.6(–4.8) | 4.10 | 3.3–4.0(–4.2) | 3.61 | 1.14 | 38 |
| Lividopora benetosta | (3.2–)3.4–4.6(–4.9) | 3.94 | (2.9–)3.0–3.9(–4.3) | 3.46 | 1.14 | 220/8 |
| Hallenberg 15301 | 3.7–4.4 | 4.10 | 3.2–3.8(–3.9) | 3.48 | 1.18 | 30 |
| Härkönen K778 | 4.0–4.8(–4.9) | 4.43 | 3.0–3.9(–4.1) | 3.62 | 1.22 | 20 |
| Lloyd 5042 | 3.6–4.3 | 4.02 | 3.1–3.8 | 3.44 | 1.17 | 10 |
| Miettinen 10394,1 | 3.8–4.6 | 4.14 | 3.3–3.9 | 3.60 | 1.15 | 5 |
| Miettinen 13647,1 | (3.3–)3.5–4.8(–4.9) | 4.03 | (3.0–)3.1–4.2(–4.3) | 3.63 | 1.11 | 32 |
| Miettinen 13891 | 3.7–4.6 | 4.08 | 3.3–3.8 | 3.59 | 1.14 | 20 |
| Miettinen 18035 | 3.2–3.8(–3.9) | 3.52 | (2.9–)3.0–3.5 | 3.21 | 1.10 | 34 |
| Miettinen 18135 | (3.4–)3.5–4.1(–4.2) | 3.82 | (3.1–)3.2–3.8(–4.0) | 3.48 | 1.10 | 30 |
| Miettinen 8823,2 | 3.5–4.2 | 4.04 | 3.0–3.5 | 3.24 | 1.25 | 5 |
| Miettinen 9023,2 | 3.7–4.3 | 3.91 | 3.2–3.8 | 3.46 | 1.13 | 24 |
| Miettinen 9166,5 | 3.6–4.2(–4.6) | 3.90 | 2.9–3.7 | 3.34 | 1.17 | 30 |
| Miettinen 9978,2 | 3.6–3.9 | 3.70 | 3.3–3.6 | 3.48 | 1.06 | 8 |
| Lividopora facilis | 3.2–4.0 | 3.50 | 2.5–3.0 | 2.69 | 1.30 | 33 |
| Lividopora subvincta | (3.4–)3.6–4.6(–5.2) | 4.02 | (2.6–)2.9–3.4(–3.5) | 3.13 | 1.28 | 90/3 |
| holotype | (3.6–)3.7–4.6 | 4.02 | (2.8–)2.9–3.3 | 3.10 | 1.30 | 30 |
| Savchenko 171124/1505 | (3.4–)3.5–4.2 | 3.87 | 2.9–3.5 | 3.17 | 1.22 | 30 |
| Savchenko 171129/1309X | (3.5–)3.6–5.1(–5.2) | 4.18 | (2.6–)2.8–3.4(–3.5) | 3.14 | 1.33 | 30 |
| Lividopora vincta | (3.2–)3.3–4.2(–4.5) | 3.80 | (2.8–)2.9–3.4(–3.5) | 3.13 | 1.21 | 62/2 |
| Lowe (CFMR L-13218-Sp) | (3.6–)3.7–4.2(–4.5) | 3.95 | 2.9–3.4(–3.5) | 3.22 | 1.23 | 30 |
| Miettinen 17916,1 | (3.2–)3.3–4.0(–4.3) | 3.65 | 2.8–3.3(–3.5) | 3.06 | 1.20 | 32 |
| Somion delectans | (5.8–)6.0–7.3(–7.6) | 6.60 | (5.0–)5.1–6.6(–6.8) | 5.64 | 1.17 | 90/3 |
| isotype | (5.8–)6.0–7.4(–7.6) | 6.59 | (5.0–)5.1–6.7(–6.8) | 5.66 | 1.16 | 30 |
| Thaxter 799 | 6.0–7.2(–7.3) | 6.61 | (5.1–)5.2–6.7 | 5.72 | 1.16 | 30 |
| Vlasák 1507/22 | (6.0–)6.1–7.2(–7.3) | 6.61 | (5.0–)5.1–6.5(–6.6) | 5.55 | 1.19 | 30 |
| Somion litschaueri | (6.6–)6.8–8.6(–9.1) | 7.71 | (4.9–)5.2–7.0(–7.7) | 6.00 | 1.28 | 120/4 |
| holotype | (6.8–)6.9–8.6(–9.1) | 7.77 | (4.9–)5.0–7.2(–7.7) | 6.14 | 1.27 | 30 |
| Vampola 198 | 6.6–8.1(–8.2) | 7.28 | (5.4–)5.5–6.3(–6.4) | 5.94 | 1.23 | 30 |
| Vlasák (JV 1309/1) | (6.7–)7.0–8.8(–8.9) | 7.69 | (5.0–)5.1–6.3(–6.6) | 5.79 | 1.33 | 30 |
| Vlasák (JV 1309/7) | (6.8–)7.3–8.8(–9.1) | 8.08 | (5.3–)5.4–7.0(–7.1) | 6.16 | 1.31 | 30 |
| Somion occarium | (5.3–)6.0–7.2(–7.6) | 6.60 | (3.9–)4.3–5.5(–6.2) | 5.02 | 1.31 | 120/4 |
| holotype | (5.3–)5.8–7.1(–7.5) | 6.47 | (4.2–)4.3–5.6(–6.2) | 5.06 | 1.28 | 60 |
| Vampola 149 | 6.0–7.5(–7.6) | 6.78 | (3.9–)4.0–5.5(–5.6) | 4.94 | 1.37 | 30 |
| Vlasák 0511/8 | (5.9–)6.0–7.2(–7.3) | 6.68 | (4.4–)4.6–5.3(–5.6) | 5.03 | 1.33 | 30 |
| Somion strenuum | (5.0–)5.2–6.4(–7.2) | 5.90 | (4.1–)4.2–5.3(–6.0) | 4.80 | 1.23 | 120/4 |
| Miettinen 10456 | (5.1–)5.2–6.3(–7.1) | 5.89 | (4.1–)4.2–5.2(–5.7) | 4.69 | 1.26 | 30 |
| Spirin 10989 | (5.0–)5.1–6.8(–7.2) | 5.75 | (4.1–)4.2–5.6(–6.0) | 4.82 | 1.19 | 30 |
| Spirin 6112 | (5.2–)5.4–6.3(–6.4) | 6.03 | (4.1–)4.2–5.5(–5.7) | 4.90 | 1.23 | 30 |
| Spirin 7330 | (5.2–)5.3–6.5(–6.8) | 5.94 | (4.1–)4.2–5.3(–5.4) | 4.77 | 1.25 | 30 |
| Somion tomsovskyi | (6.4–)6.8–8.3(–8.7) | 7.50 | (5.1–)5.5–6.8(–7.1) | 6.11 | 1.23 | 60/2 |
| Vlasák Jr. (JV 1209/55) | (6.4–)6.8–8.2(–8.7) | 7.47 | (5.2–)5.4–6.9(–7.1) | 6.05 | 1.23 | 30 |
| Vlasák Jr. (JV 1307/8) | 6.8–8.3(–8.6) | 7.55 | (5.1–)5.5–6.8(–7.1) | 6.18 | 1.22 | 30 |
| Somion unicolor | (5.2–)5.3–7.1(–7.3) | 6.13 | (4.0–)4.2–5.4(–5.9) | 4.78 | 1.28 | 90/3 |
| Lewis DAOM 9080 | (5.3–)5.8–7.2(–7.3) | 6.38 | (4.1–)4.2–5.5(–5.6) | 4.77 | 1.34 | 30 |
| Vlasák (JV 1708/10) | 5.2–6.7(–6.8) | 5.88 | (4.0–)4.1–5.4(–5.9) | 4.82 | 1.22 | 30 |
| Vlasák Jr. (JV 1304/1) | (5.4–)5.5–6.9(–7.0) | 6.11 | (4.1–)4.2–5.3(–5.8) | 4.74 | 1.29 | 30 |
Irpiciporus mollis (Berk. & M.A. Curtis) Murrill, Bull. Torrey Bot. Club 32: 471, 1905. Fig. 9.
Basionym: Irpex mollis Berk. & M.A. Curtis, Hooker’s J. Bot. 1: 236, 1849.
Typus: USA, South Carolina, Santee River, unknown collection date, leg. Ravenel, herb. Curtis 1729 (lectotype K(M) 64592, studied – selected by Murrill 1905: 471).
Basidiocarps annual or biennial, sessile or effused-reflexed, rarely completely resupinate, pilei projecting up to 3 cm. Upper surface pubescent, azonate, cream coloured to pale ochraceous, in oldest parts almost smooth. Edge of pileus sharp, fertile, concolourous with pileal surface. Hymenial surface more or less concave, cream coloured to pale ochraceous, in very old basidiocarps brownish; pores incomplete, shallow, present only in marginal areas, 1–2 per mm, quickly becoming dentate to spathulate and finally transforming to flattened, sharp-pointed spines, about 1 per mm. Section: context cream coloured, in old herbarium specimens pale ochraceous, watery in fresh condition, firm, distinctly fibrillose and sometimes indistinctly zonate when dry, up to 2 cm thick; hymenial layer tough, concolourous with or slightly paler than hymenial surface, up to 1.5 cm thick.
Hyphal structure monomitic; all septa with clamp connections. Context hyphae very thick-walled, interwoven to subparallel, (4.3–)5.2–6.2(–6.7) μm diam. Tramal hyphae slightly to distinctly thick-walled (lumen wide to capillary), subparallel, (2.8–)3.4–4.3(–5.2) μm diam. Subhymenial hyphae thin- to slightly thick-walled, some short-celled and inflated, 3–5 μm diam. Basidiospores slightly thick-walled, broadly ellipsoid to subglobose, (4.8–)5.1–6.2(–6.3) × (4.0–)4.3–5.3(–6.0) μm, L = 5.45 μm, W = 4.84 μm, Q = 1.11–1.14.
Distribution and ecology: Widely distributed in the eastern part of North America, reaching Florida at the southernmost limit of its distribution. Occurs on many angiosperm tree species, and Gilbertson & Ryvarden (1987) report it from living trees, but we have not been able to find any reference that it would be pathogenic. It also grows on dead trees.
Notes: This species was originally described from South Carolina (Berkeley & Curtis 1849) and recognized as such until Kotlaba & Pouzar (1957) placed it among the synonyms of the European species I. pachyodon. However, both morphological and DNA data confirm that they are different species, whose distribution areas do not seem to overlap. Irpiciporus mollis is distributed in the eastern part of USA and Canada (Gilbertson & Ryvarden 1987, as S. pachyodon). According to Murrill (1905) and Maas Geesteranus (1974), Irpex crassus Berk. & Curtis and Irpex crassitatus Lloyd are conspecific with I. mollis. Ryvarden (2020b) lists further junior synonyms.
Irpiciporus pachyodon (Pers.) Kotl. & Pouzar, Česká Mykol. 11: 156. 1957. Figs 2, 9.
Basionym: Hydnum pachyodon Pers., Mycol. Europaea 2: 174. 1825.
Synonym: Hydnum schestunovii Nikol., Notulae Syst. Sect. Cryptogam. Inst. Bot. 6: 38. 1949 (fide Nikolaeva 1964).
Typus: France, Delastre (lectotype of Hydnum pachyodon L 910.263– 1321 – selected and studied by Maas Geesteranus 1974: 491).
Basidiocarps annual or biennial, effused-reflexed to completely resupinate, pilei projecting up to 5 cm. Upper surface pubescent, azonate, cream coloured to pale ochraceous, in oldest parts almost smooth. Edge of pileus sharp to rather blunt, fertile, concolourous with pileal surface. Hymenial surface more or less concave, cream coloured or yellowish, in very old basidiocarps pale ochraceous; pores incomplete, shallow, present only in marginal areas, 0.5–1 per mm, quickly becoming dentate to lamellate and finally transforming to flattened, sharp-pointed spines, 0.5–1 per mm. Section: context almost white to cream coloured, tough in fresh condition, compact when dry, up to 3 cm thick; hymenial layer tough, concolourous with or slightly paler than hymenial surface, up to 2 cm thick.
Hyphal structure monomitic; all hyphae with clamp connections. Context hyphae thin- or only slightly thick-walled, easily collapsing, interwoven to subparallel, (4.7–)4.9–6.0(– 6.8) μm diam. Tramal hyphae thin- or slightly thick-walled, subparallel, (3.0–)3.3–4.1(–4.5) μm diam. Subhymenial hyphae thin-walled, some short-celled and slightly inflated, 3.0–4.5 μm diam. Basidiospores slightly thick-walled, broadly ellipsoid to subglobose, (5.2–)5.5–6.5(–7.4) × (4.2–)4.5–5.6(–6.4) μm, L = 6.02 μm, W = 5.09 μm, Q = 1.15–1.22.
Distribution and ecology: Irpiciporus pachyodon is a temperate European species inhabiting mostly living oak trees (Ryvarden & Melo 2014). It has also been reported from Caucasus (Nikolaeva 1964).
Notes: Irpiciporus pachyodon is the European counterpart of North American I. mollis. Morphological differences between these species are subtle: tramal hyphae of I. pachyodon are slightly narrower than in I. mollis and not so thick-walled, and its basidiospores are slightly larger.
Irpiciporus revolubilis (Hjortstam & Ryvarden) Nakasone, Lilloa 59 (Suppl.): 97. 2022. Fig. 9.
Basionym: Radulodon revolubilis Hjortstam & Ryvarden, Syn. Fungorum 23: 88. 2007.
Typus: Venezuela, Aragua, Parque National Henri Pittier, Rancho Grande Research Station, on decayed hardwood, 14 Apr. 1999, Ryvarden 41417 (holotype O, studied).
Basidiocarps annual, effused, up to 5 cm in longest dimension. Margin sharply compact, delimited, up to 1 mm, detaching and rolling in dry basidiocarps. Hymenial surface cream coloured to pale ochraceous; hymenophore irpicoid, spines sharp to rather blunt, 3–5 per mm, partly fusing together and forming dentate or spathulate projections. Section: context cream-colored, soft, up to 0.5 mm thick; hymenial layer soft, concolourous with or slightly paler than hymenial surface, up to 0.3 cm thick.
Hyphal structure monomitic, all septa with clamp connections. Context hyphae slightly to distinctly thick-walled, interwoven to subparallel, (3.4–)4.1–5.0(–5.6) μm diam. Tramal hyphae slightly to distinctly thick-walled, predominantly subparallel, (2.5–)2.7–4.1(–5.1) μm diam. Subhymenial hyphae not differentiated from tramal ones. Basidiospores slightly thick-walled, ellipsoid to broadly ellipsoid, more rarely subglobose, (4.2–)4.3–5.0(–5.1) × (3.3–)3.5–4.3(–4.4) μm, L = 4.63 μm, W = 3.98, Q = 1.17.
Notes: We agree with Nakasone & Ortiz-Santana (2022) that this species belongs to Irpiciporus. It has the smallest spores among the species in the genus and reminds closely of the African I. branchiformis.
Irpiciporus sinuosus Y.C. Dai & Chao G. Wang, Mycol. Progr. 21(73): 8. 2022.
Typus: China, Yunnan, Puer, Laiyanghe Forest Park, angiosperm, 6 Jun. 2011, Dai 12234 (holotype BJFC 010517).
Notes: This species has well-developed pores, even though they start to split soon (Zhao et al. 2017). It is the first truly poroid species confirmed to belong to Irpiciporus.
Lividopora Miettinen, gen. nov. MycoBank MB 849645.
Type species: Lividopora facilis Miettinen
Etymology: Derived from lividum (Lat., adjective), livid, refers to the greyish (dull) tint of the basidiocarps.
Resupinate annual to short-lived perennial polypores with reddish to grey colours, leathery tough when fresh, drying hard, with a distinct margin. Pores regular, mid-sized to small (5–15 per mm) thin-walled and entire. Brown, black or red basal layer present. Hyphal system dimitic, clamps absent, weakly to moderately cyanophilous, IKI-, KOH-, CRB lilac. Skeletal hyphae interwoven but not agglutinated, with a visible narrow lumen, generative hyphae slightly thick-walled, dominating in lower tube trama. The overall impression of hyphal structure is messy. Two main types of cystidia: tramal encrusted skeletocystidia are clavate, abundant and conspicuous, embedded or penetrating hymenium; thin-walled, often mamillate, slightly projecting, sack-like hymenial cystidia also present, often with a stained plasma and could be called gloeocystidia. In addition to these, encrusted and naked hyphidia in hymenium. Basidia with four sterigmata, barrel-like to clavate. Basidiospores ellipsoid to subglobose, smooth, mid-sized, thin-walled or with distinct walls, devoid of guttulae.
Notes: Incorporation of ITS sequences from public nucleotide databases in our analyses (Fig. 10) shows that two Lividopora species are widespread, L. benetosta in the Paleotropics and Caribbean, and L. vincta in the Neotropics. We could not find public sequences of the other three species. Both L. benetosta and L. vincta show some ITS variation, but differences are small, giving no reason to recognize more species in the genus.
Fig. 10.
Bayesian consensus phylogram of Lividopora spp. based on ITS sequences. Countries (and states) of origin are denoted with ISO 3166 codes.
Species of Lividopora are similar microscopically, and in many cases macroscopic characters of the basidiocarp such as colour (Fig. 11) and pore size are more useful for identification. Geographic origin too is of help, since all but one species seem to be restricted to some part of the tropics. However, young specimens, for instance in the Caribbean where both L. benetosta and L. vincta occur, can be very difficult or even impossible to identify with certainty by their morphology.
Fig. 11.
Species of Lividopora. A. L. armeniaca (holotype). B. L. benetosta, young basidiocarp (Miettinen 18133). C. L. benetosta, old basidiocarp (Miettinen 13011.3). D. L. facilis (holotype). E. L. subvincta (Savchenko 171124/1505). F. L. vincta (Vlasák 1704/102). Scale bars = 1 cm.
Table 4 provides key identification characters. For cultural characters and further morphological characters of the group, we recommend Setliff (1972a, b). He notes that L. vincta coll. produce clamps in culture.
Table 4.
Comparison of morphological characters of Uvidopora spp.
| Species | Encrusted cystidia (L and W in μm) | Pore size (60 % mid range) | Spores (L and W in μm) | Color | Tramal skeletal hyphae (μm in diameter, 60 % mid range) | Other |
|---|---|---|---|---|---|---|
| L. armeniaca | Narrow, L = 23, W = 7.2 | 10-12 | Subglobose, L = 4.10, W = 3.61, Q = 1.14 | Orange when fresh, dries brick | Yellowish, narrow, 2.5-3.0 | — |
| L. benetosta | Most very broad and short (Q < 2), L = 34, W = 14.9 | 8-13 | Subglobose, L = 3.94, W = 3.46, Q = 1.14 | Faded reddish when young, brownish- grayish when old | Yellow to brown, wide, 3.0-4.0 | Gloeocyst?dia commonly > 10 μm wide |
| L. facilis | Narrow, L = 21, W = 9.7 | 5-6 | Ellipsoid, L = 3.5 μm, W = 2.69 μm, Q = 1.30 | Faded reddish, dries brown | Almost hyaline, narrow, 2.8-3.3 | — |
| L. subvincta | Broad and long, L = 32, W = 11 | 9-11 | Ellipsoid, L = 4.02 μm, W = 3.13 μm, Q = 1.28 | Dark gray | Brown, wide, 3.2-4.2 | — |
| L. vincta | Broad and long, L = 47, W = 14.6 | 9-11 | Ellipsoid, L = 3.80, W = 3.13, Q = 1.21 | Reddish | Yellowish, wide, 3.7-4.5 | — |
Skeletocystidia (Figs 12, 13) appear first as thin-walled, swollen hyphal ends with sparse encrustation, often in hymenium, though rooted in trama. At this stage, they may appear similar to the permanently thin-walled hymenial cystidia (“gloeocystidia”). Later in development the skeletocystidia become thick-walled and obtain a coarse and thick crystal cover that finally obscures view to the hyphae inside the cystidia. The two types are easy to distinguish in slides, even though, pending on developmental stage, the thin-walled “gloeocystidia” may be rare or only found in some parts of the basidiocarp. Cystidial encrustation is very persistent, visible even in otherwise destroyed (old, mouldy, or sterile) specimens.
Fig. 12.
Lividopora facilis basidiome hyphal structures (subiculum, trama, and encrusted cystidia) and spores of the five Lividopora species treated here.
Fig. 13.
Cystidia of Lividopora spp.
Lividopora spp. have been included in Rigidoporus by Ryvarden (1972b) and Corner (1987) as R. vinctus and R. hypobrunneus (= L. benetosta below). Even though not closely related, the two genera share morphological characters such as cyanophilous simple-septate hyphae in basidiocarps, ellipsoid to subglobose spores, short and broad, barrel-like hymenial cells, and heavily encrusted, thick-walled club-like tramal cystidia. Their main difference is in the hyphal structure, which is distinctly dimitic in Lividopora spp. and monomitic or indistinctly dimitic in Rigidoporus spp. The structure of trama is different: hyphae are parallel in most Rigidoporus spp. and related Physisporinus spp. but interwoven in Lividopora. Spores of Rigidoporus are cyanophilous and usually slightly thick-walled, whereas in Lividopora spp. they are thin-walled and acyanophilous.
Ryvarden (1972b) considered the hyphal system of L. vincta monomitic, consisting of apparent skeletal hyphae or their segments, but with transitions to generative hyphae. He softened his stand later, settling for “apparently dimitic” (Gilbertson & Ryvarden 1987). Intermediary hyphae are not a rare phenomenon in dimitic polypores. In our view, the intermediary hyphae are not prevalent in Lividopora, and for all practical purposes (normal morphological examination and functionality for the fungus), the structure may be called dimitic.
Lividopora armeniaca Miettinen & J. S. Seelan, sp. nov. MycoBank MB 849646. Figs 11–13.
Typus: Malaysia, Sabah, Ranau. Kinabalu Park, Timpohon peak trail, 6.02775° 116.54527°, alt. 1 880 m, upper montane rainforest, on a fallen crown of a dicot (24 cm diam, decay stage 3/5), 14 Jun. 2013, Miettinen 16136 & Seelan (holotype SNP33533, isotype H 7200338*).
Etymology: Armeniacus (Lat., adj.), apricot-coloured, refers to basidiocarp colour.
Basidiocarps resupinate, apricot-coloured when fresh, drying dull reddish brown, patches up to 7 × 3 cm and 2 mm thick. Consistency hard woody when dry, curving inwards upon drying, detaching from wood. Pores thin-walled, regular, angular, mouths smooth, (10–)11–12(–13) per mm, up to 1.2 mm long. Subiculum cream-colored, in contrast to darker tubes, 0.2–0.6 mm thick. Basal layer in dry state a dark, reddish waxy film, orange when fresh.
Hyphal structure dimitic, clamps absent. Generative hyphae thin- to slightly thick-walled, frequently septate, uniform except in basal layer, 2.0–3.0(–3.6) μm diam. Subiculum dominated by skeletal hyphae, interwoven, winding, yellowish to hyaline, tissue rather loose; basal layer about 20 μm, strongly agglutinated, brown, (2.7–)3.3–4.2(–4.5) μm diam, with a distinct lumen third to sixth of the total cell width. Tramal tissue dense, hyphae interwoven to subparallel, dominated equally by slightly thick-walled generative hyphae and slightly yellowish skeletal hyphae (2.1–)2.5–3.0(–3.5) μm diam, towards tube mouths by generative hyphae. Cystidia: Tramal skeletocystidia abundant, often bending into hymenium, (7–)15–30(–47) × (5.3–)6.3–8(–12) μm, L = 23.0 μm, W = 7.2 μm (n = 37). Thin-walled hymenial cystidia rather narrow, clavate, few mamillate, heavily but finely encrusted, 11–40 × 4.7–8.8 μm, W = 6.1 μm (n = 13). Basidia barrel-like, 8–10 × 4.2–5.5 μm. Basidiospores broadly ellipsoid, thin-walled, (3.7–)3.8–4.6(–4.8) × 3.3–4.0(–4.2) μm, L = 4.10 μm, W = 3.61 μm, Q = 1.14.
Distribution and ecology: Known from dead wood from a montane rainforest in Sabah, North Borneo.
Notes: The type specimen reminded of a thin Rigidoporus microporus specimen when fresh. Lividopora benetosta may look similar, for differences see Table 4. The type is well developed but does not contain any old parts. This should be taken into account when interpreting cystidial characters, which are age-dependent in Lividopora.
Lividopora benetosta (Berk.) Miettinen, comb. nov. MycoBank MB 849647. Figs 1, 11–13.
Basionym: Polyporus benetostus Berk., Bot. J. Linn. Soc. 16: 52. 1877.
Synonyms: Poria fulvobadia Pat., J. Bot. (Morot) 11: 340. 1897.
Poria fumosa Bres. & Pat., Mycological Writings 1(6): 49. 1901.
Poria porphyrophaea Bres., Hedwigia 56: 296. 1915.
Poria hypobrunnea Petch, Ann. Roy. Bot. Gard. (Peradeniya) 6: 137, 1916.
Poria vincta var. cinerea (Bres.) Setliff, Mycologia 64: 695. 1972, pro parte.
Typus: French Polynesia, Tahiti, on bark, 24 Sep. 1875, Challenger Expedition (holotype of Polyporus benetostus K(M) 192246, ex herb. Berkeley, studied). Vietnam, Thanh Hóa, 20 Apr. 1892, Bon 5294 (lectotype of Poria fulvobadia FH 290623 – selected by Ryvarden (1983), studied). Samoa, Lloyd 5042 (lectotype of Poria fumosa BPI US0318515 – selected by Stevenson & Cash 1936: 1940, isotype FH 290621 studied). Philippines, Mindanao. Zamboanga, San Ramon, 12 May 1904, Copeland 743 (lectotype of Poria porphyrophaea NY 00742723 – selected by Ryvarden 1988). Sri Lanka, Gangaruwa, Dec. 1913, Petch 3930 (lectotype of Poria hypobrunnea K(M) 56199 – selected by Setliff (1972b), studied).
Basidiocarps resupinate, annual or more rarely lasting for 2–3 growth seasons, juvenile fruiting bodies nearly white, quickly attaining reddish-greyish colour ranging from nearly orange, purplish or pinkish to brick-colour with a grey overlay, later dark brown or grey; colours fade after drying, patches from a few cm to a couple of dm, 0.5–2(–4) mm thick. Old basidiocarps curving and bone-hard when dry, tough leathery when fresh. Pores regular, rounded, thin-walled, (7–)9–13(–16) per mm, median 8–15 so quite variable between specimens. Subiculum cream coloured when young, brown when old, cottony, topped by a brown, agglutinated basal layer, which is also visible between annual layers, 0.2–0.5 mm. Margin abrupt, very narrow, if any sterile part at all, sometimes a narrow beige or cream-colored band of younger growth in contrast to darker old pores.
Hyphal structure dimitic, clamps absent. Generative hyphae slightly thick-walled, yellowish, (1.5–)2.0–3.4(–4.2) μm diam. Subiculum dominated by interwoven brownish skeletal hyphae, (2.4–)3.0–4.3(–5.4) μm diam with a usually distinct lumen, 1/4 to 1/6 of total width. Tramal tissue dense, interwoven, difficult to study but not agglutinated, lower trama dominated by generative hyphae or equally by skeletal hyphae, (2.0–)3.0–4.0(– 4.8) μm diam. Cystidia: Skeletocystidia abundant and persistent, embedded in trama, heavily encrusted, encrustation commonly short but wide, (12–)20–45(–155) × (8–)11.5–18(–26), L = 33.6 μm, W = 14.9 μm (n = 134/15), width up to 17 μm when naked; in slides it is typical to see only large ellipsoid crystal clumps and not the root of the cystidia. Hymenial gloeocystidia mamillate, varying in number but often numerous, broad and conspicuous, (10–)14–19.5(–31) × (5–)9–11.2(–16), W = 10.1 μm (n = 44/11). Basidia clavate to barrel-shaped, 7.5–17 × 4.6–6.5 μm. Basidiospores broad ellipsoid to subglobose, (3.2–)3.4–4.6(–4.9) × (2.9–)3.0–3.9(–4.3) μm, L = 3.94 μm, W = 3.46 μm, Q = 1.10– 1.22.
Distribution and ecology: Widely distributed in tropical and subtropical areas in the Old World and Pacific, in the southern hemisphere reaching Australia and New Zealand. In the Neotropics known from the Caribbean. Basidiocarps develop on dead wood of various angiosperms but known also for attacking living trees.
Notes: Hymenophore colour changes drastically with age from light-coloured to brown or grey. Specimens have a pink or purple tinge combined with dull greyness, except in senescent specimens that lose all reddish colour. Microscopically, subglobose spores and wide but short cystidial encrustation are characteristic. Young specimens, where cystidial characters and grey colour are not well developed, might be difficult to tell apart from L. vincta.
Lividopora benetosta is a very common species in old world tropics. Poria vincta var. cinerea of Setliff (1972a, b) is largely based on L. benetosta, but also on L. subvincta and possibly other species as well. Corner (1987) adopted Poria hypobrunnea for this species. Corner’s description and the type of this species fit well our concept of L. benetosta. However, Poria hypobrunnea is just one name in a long list of synonyms of Lividopora benetosta, and one of the most recent ones.
The reports on Acacia heartwood rot caused by Rigidoporus hypobrunneus (Lee & Noraini Sikin 1999) probably refer to L. benetosta as defined here. Data by Martin et al. (2015) on endophytic fungi shows that L. benetosta is rather common on living rubber trees (Hevea brasiliensis) in Cameroon, and we speculate that it could be a pest of rubber plantations.
Lividopora facilis Miettinen, sp. nov. MycoBank MB 849648. Figs 11, 12.
Typus: Indonesia, Riau, Indragiri Hulu, Bukit Aluran Babi, -0.83541° : 102.2278° ± 140 m, alt. 150 m, secondary, half-open forest on moist, level ground, fallen branch on the ground (Anthocephalus?, 3 cm diam, decay stage 2/5), 29 Jun. 2004, Miettinen 8742* (holotype BO, isotype H 7200351).
Etymology: Facilis (Lat., adj.), easy, referring to easy identification of this species.
Basidiocarps resupinate, greyish pinkish or faded brick colour, like a dull version of Steccherinum collabens, in senescent parts light ochraceous brown, patches of 2–5 × 1–2 cm, 0.4–1 mm thick. Consistency tough, woody when dry. Pores rather regular in size, thin-walled, rounded angular; mouths whitish pruinose due to projecting hyphal ends, 5–6(–7) per mm. Subiculum very thin, white, lighter in colour than pores, ≤ 0.1 mm thick. A thin basal layer with a reddish-brownish colour present.
Hyphal structure dimitic, clamps absent. Generative hyphae uniform, thin- to slightly thick-walled, (1.5–)1.8–2.8(–3.2) μm diam. Subiculum dominated by interwoven, faintly yellowish to hyaline skeletal hyphae, (2.5–)2.6–3.3(–5.0) μm diam, their lumen visible and 1/6–1/3 of total width, tissue rather loose. A very tightly packed basal layer of 20–40 μm composed of slightly thick-walled generative hyphae is found next to the substrate. Tramal hyphae interwoven to subparallel, skeletal hyphae (2.4–)2.8–3.3(–3.9) μm diam, tissue rather dense but not agglutinated. Dominance of skeletal hyphae fades towards tube mouths, which are nearly monomitic. Cystidia: Encrusted hyphal ends in trama, occasionally bending into hymenium, when young slightly thick-walled generative hyphal ends that later develop into larger thick-walled skeletocystidia, (7–)12.5– 27.6(–55) × (6–)8.7–10.8(–14) μm, L = 20.8 μm, W = 9.7 μm (n = 24), up to at least 10 μm wide without encrustation. The second type of cystidia (“gloeocystidia”) often mamillate, 9.4–20 × 5–8, μm W = 6.3 μm (n = 18), projecting up to 10 μm beyond hymenium. Basidia clavate to cylindrical, 8.5–14 × 4.3–5.5 μm. Basidiospores thin-walled, ellipsoid, 3.2–4.0 × 2.5–3.0 μm, L = 3.5 μm, W = 2.69 μm, Q = 1.3.
Distribution and ecology: Known from dead dicot wood from a secondary lowland rainforest in Sumatra.
Notes: Larger pores and clearly narrower spores separate L. facilis from other Lividopora species.
Lividopora subvincta (Ryvarden) Miettinen, comb. nov. MycoBank MB 849649. Figs 11–13.
Basionym: Rigidoporus subvinctus Ryvarden, Syn. Fungorum 40: 105. 2020.
Synonym: Poria vincta var. cinerea (Bres.) Setliff, Mycologia 64: 695. 1972. pro parte.
Typus: Zimbabwe, Manicaland, Vumba, Leopard rock, angiosperm, 14 Mar. 1995, Ryvarden 37098* (holotype of Rigidoporus subvinctus O-F- 76331, studied).
Basidiocarps resupinate, annual to biennial, dark grey, patches of a few cm to dm, 0.5–2 mm thick. Consistency hard when dry, curving inwards upon drying. Pores regular, round, (7–)9–12(–14) per mm. Subiculum brown, in younger parts cream coloured, basal layer a thin, waxy black line, visible between annual layers, 0.2 mm. Margin abrupt or an up to 1 mm wide light-coloured sterile zone.
Hyphal structure dimitic, clamps absent. Generative hyphae slightly thick-walled, (1.9–)2.2–2.8(–3.4) μm diam. Subiculum dominated by interwoven, brown skeletal hyphae, basal layer with partly parenchymatic tissue, apparently consisting of both skeletal and generative hyphae, skeletal hyphae (3.4–)3.7–4.8(– 5.6) μm diam, with a distinct lumen 1/3–1/6 of total width. In trama skeletal hyphae similar to subicular hyphae, interwoven, dominant in upper trama, (2.4–)3.2–4.2(–5.0) μm diam; generative hyphae dominate close to tube mouths. Cystidia: Skeletocystidia abundant, encrusted heavily, ranging from mid-sized to broad, usually encrustation long, (9.5–)23–42(–58) × (6.8–)9.4–12(–17) μm, L = 31.6 μm, W = 11.0 μm, (n = 75/3), up to at least 9.5 μm in width without encrustation. Stained thin-walled hymenial cystidia variable in numbers, may be locally abundant close to tube mouths, round, partly mamillate, (13–)14–18.3(–40) × (5.5–)6.8–8.2(–8.8) μm, W = 7.4 μm (n = 27/3). Basidia clavate to barrel-shaped, 8.8–10 × 5.4–6 μm. Basidiospores broad ellipsoid to subglobose, with distinct walls and no guttulae, (3.4–)3.6–4.6(–5.2) × (2.6–)2.9–3.4(–3.5) μm, L = 4.02 μm, W = 3.13 μm, Q = 1.22–1.30.
Distribution and ecology: Known from Kenya, Tanzania, and Zimbabwe from Cupressus and dicot wood; tree pathogen causing root rot.
Notes: This species is dark already when young unlike the other African species of Lividopora, L. benetosta. Basidiocarps are darker than in L. benetosta also when older. According to Ryvarden (2020a), this species is different from “Rigidoporus vinctus” by having two types of cystidia, while the latter has only one type. This is incorrect, as we have shown here that all Lividopora, including L. vincta, have two types of cystidia. His concept of R. vinctus may be mixed (including some Meripilaceae), but he quite correctly likened the two species when describing L. subvincta. Microscopic differences include slightly narrower spores in L. subvincta (Q > 1.2) and shortly but widely encrusted skeletocystidia in L. benetosta as opposed to long encrustation in L. subvincta.
Setliff & Mesner (1971) report this species as Poria vincta var. cinerea as a tree plantation pest from Mt. Meru, Tanzania. We sequenced a Tanzanian strain of Setliff (ECS-194-R) very likely associated with this study. Later their concept of the aforementioned variety included also L. benetosta, as can be deduced from their list of studied specimens (Setliff 1972b).
Lividopora vincta (Berk.) Miettinen, comb. nov. MycoBank MB 849650. Figs 11–13.
Basionym: Polyporus vinctus Berk., Ann. Mag. Nat. Hist. 9: 196. 1852.
Synonym: Polyporus carneopallens Berk., Hooker’s J. Bot. Kew Gard. Misc. 8: 235, 1856.
Typus: Dominican Republic, Santo Domingo, unknown collection date, Sallé 34 (holotype of Polyporus vinctus K(M) 167866, studied). Brazil, Amazon, Rio Uaupés, Ipanoré (“Panuré”), on dead trees, Feb. 1853, Spruce 178 (lectotype of Polyporus carneopallens designated here K(M) 192248, MBT 10014556, studied; isolectotype FH 00290615, studied).
Basidiocarps resupinate, orange reddish or pinkish when fresh, drying duller reddish ochraceous, 1–2.5 mm thick. Consistency hard when dry. Pores regular, rounded, (7–)8–10(–12). Subiculum ochraceous, 0.2–1 mm thick, basal waxy, red to black layer present, 20–100 μm thick. Margin cream coloured.
Hyphal structure dimitic, clamps absent. Generative hyphae slightly thick-walled, CB(+), (1.7–)2.2–3.0(–3.8) μm diam. Subiculum dominated by interwoven, yellowish skeletal hyphae, loose to rather tight, (2.3–)3.1–4.6(–5.4) μm diam, with a distinct lumen of 1/3–1/6 total width. Basal layer monomitic, composed of agglutinated, thick-walled generative hyphae, (3.2–)3.7–4.7(– 5.0) μm diam. Tramal skeletal hyphae interwoven, (2.0–)3.7– 4.6(–5.9) μm diam, dominate in upper trama, less so towards tube mouths where hyphae are subparallel, tissue dense but not agglutinated. Cystidia: Skeletocystidia clavate, large and heavily encrusted, (17–)31–60(–105) × (7–)9.8–20(–23) μm, L = 46.1 μm, W = 14.8 μm (n = 94/5), up to 12.5 μm in width when naked. Thinwalled hymenial cystidia clavate to mamillate, (10–)14–40(–46) × (4.6–)7.0–9.5(–12.4) μm, W = 8.2 μm (n = 34/5). Basidia not seen, basidioles 7.5–10.5 × 4.5–5.3. Basidiospores broad ellipsoid, with thin to distinct walls, (3.2–)3.3–4.2(–4.5) × (2.8–)2.9–3.4(–3.5) μm, L = 3.80 μm, W = 3.13 μm, Q = 1.20–1.23.
Distribution and ecology: Found in tropical and warm temperate Americas. Endophyte DNA data of Martin et al. (2015) show that L. vincta appears to be common on living Hevea brasiliensis in natural forests in Brazil and Peru.
Notes: The name Rigidoporus vinctus has been interpreted confusingly in the literature and herbaria, and we know from our own experience that it covers many species. Part of the material under this name belongs to Meripilaceae, and part of it to Lividopora.
The distributions of L. benetosta and L. vincta overlap at least in the Caribbean. Lividopora vincta is lighter in colour than L. benetosta, its spores are narrower and its cystidia are long, not short and wide as often seen in L. benetosta (Table 4).
There is some ITS variation in L. vincta (Fig. 10), and it would be interesting to see a more in-depth study of this species with more specimens and several markers. It may yet turn out to be a species complex, but ITS variation is small and gradual enough to be the result of geographic spread of sequenced specimens or quality issues.
Pseudolagarobasidium J.C. Jang & T. Chen, Trans. Brit. Mycol. Soc. 85: 374. 1985.
Type species: Pseudolagarobasidium subvinosum (Berk. & Broome) Sheng H. Wu
Notes: Hallenberg et al. (2008) showed that Pseudolagarobasidium, a genus of hydnoid wood-inhabiting resupinate fungi, is related to Cerrena. Nakasone & Lindner (2012) gave a taxonomic treatment of the genus recently, and good illustrations of Pseudolagarobasidium species can be found in Maekawa & Hasebe (2002) and Wood & Ginns (2006). Nakasone & Ortiz-Santana (2022) expanded the genus so that in their view it includes 11 species. We have shown here that Acanthodontia cirrhatina does not belong to Pseudolagarobasidium, as they suggested, and we exclude Hyphoradulum conspicuum from the genus.
The genus would require a revision with properly sequenced material to ascertain the real species number. In particular, the paleotropical Pseudolagarobasidium species should be revised, and historical names should be checked against newly described species. It would appear there are several closely related species parasitic on Fabaceae. Currently, the six species listed below have been sequenced and described reliably enough that we conclude that they belong to the genus. They are listed below. For two of them, only LSU data is available, making integrative species-level comparison within the genus problematic at present. We consider the remaining names as insufficiently known taxa.
Our ITS-based tree of all publicly available sequences (Fig. 14) represents nominally four species (P. acaciicola, P. baiyunshanensis, P. belizense, and P. pallens). We find it difficult to interpret these results. Species number may vary between three and seven. We suggest future papers utilize another marker beside ITS to delimit species.
Fig. 14.
Bayesian consensus phylogram of Pseudolagarobasidium spp. based on ITS sequences. Red circles denote type specimens. Countries (and states) of origin are denoted with ISO 3166 codes.
Thin-walled hymenial cystidia just like those shared by other genera of the Cerrena clade are found in the genus. Pseudolagarobasidium species are also dimitic and their blunt, raduloid (“subporoid”) hymenophore reminds of old, irpicoid Cerrena a lot. However, hyphal structure in Pseudolagarobasidium is mostly monomitic and skeletal hyphae are found only in the basal part of the basidiocarp. These skeletal hyphae are furthermore peculiar “microbinding hyphae”, i.e. narrow and regularly branching, quite unlike the regular, rarely branching skeletal hyphae in Cerrena.
Accepted species with DNA sequences available
Pseudolagarobasidium acaciicola Ginns, Canad. J. Bot. 84: 752. 2006.
Note: Even though Wood & Ginns (2006) do not mention sequence accession numbers, they published ITS sequences of two paratypes (GenBank DQ517882, DQ517883), complemented with a LSU (GenBank EU569321) by Hallenberg et al. (2008).
Pseudolagarobasidium baiyunshanense M.L. Han, L.S. Bian & Q. An, Phytotaxa 483: 171. 2021.
Pseudolagarobasidium belizense Nakasone & D.L. Lindner,
Fungal Diversity 55: 158. 2012.
Pseudolagarobasidium subvinosum (Berk. & Broome) Sheng H. Wu, Acta Bot. Fenn. 142: 113. 1990. Fig. 2.
Basionym: Hydnum subvinosum Berk. & Broome, J. Linn. Soc., Bot. 14(73): 60. 1873 [1875].
Synonym: Pseudolagarobasidium leguminicola J.C. Jang & T. Chen, Trans. Brit. Mycol. Soc. 85: 374. 1985.
Typus: Sri Lanka, Peradeniya, Nov. 1867, no. 180 (holotype of Hydnum subvinosum K). Taiwan, Hua-Ling, Fung-Ping, Leucaena leucocephala, Feb. 1983, Jang & Chen (holotype of Pseudolagarobasidium leguminicola TAI 9020).
Notes: This species is distinctive enough that we trust the conclusion of Nakasone & Lindner (2012) that the generic type P. leguminicola and P. subvinosum belong to the same species, or at least are closely related. An LSU sequence (GenBank EU569319) was published by Hallenberg et al. (2008).
Pseudolagarobasidium pronum (Berk. & Broome) Nakasone & D.L. Lindner, Fungal Diversity 55: 162. 2012.
Notes: Hallenberg et al. (2008) provide an LSU sequence (GenBank EU569320) based on a Taiwanese specimen of Wu identified as P. calcareum, a species described from the southern part of Australia. This LSU sequence clearly belongs to Pseudolagarobasidium. We have studied Wu’s Taiwanese collection of P. calcareum, the same one studied by Nakasone & Lindner (2012), and it is very similar to P. belizense and thus a true Pseudolagarobasidium. Nakasone & Lindner (2012) concluded that this species is a synonym of P. pronum, which was described from Sri Lanka. Now that species diversity in the genus has increased, also the identity of P. calcareum against P. pronum should be re-assessed. We have not studied the types involved. If they belong to separate species of Pseudolagarobasidium, an affinity of Taiwanese material to Sri Lankan P. pronum appears more likely than to the South Australian P. calcareum.
Pseudolagarobasidium venustum (Hjortstam & Ryvarden) Nakasone & D.L. Lindner, Fungal Diversity 55: 165. 2012.
Basionym: Radulodon venustus Hjortstam & Ryvarden, Mycotaxon 74: 250, 2000.
Synonym: Pseudolagarobasidium pallens Motato-Vazq. & Westphalen, Phytotaxa 555: 163. 2022.
Typus: Brazil, São Paulo, Reg. Santos, Cananeia, Ilha do Cardoso, on bark of palm, 2 Feb. 1987, Hjortstam 16838 (holotype of of Radulodon venustus K(M) 77909, studied).
Notes: Our sequenced material from Costa Rica and Puerto Rico agrees well with the type. The sequences are near identical with the Brazilian material that Westphalen & Motato-Vásquez (2022) described as P. pallens. They cited as main differences yellow to orange colour and smaller spores of P. venustum, though apparently without studying the type of P. venustum. The protologue of P. venustum states that the colour is at first whitish and later straw-coloured. Their statement about colour probably refers to Nakasone & Lindner (2012), who studied the type but also included other specimens in their description, none of which was sequenced, and whose identity we cannot confirm. Spores are of equal width and a bit longer in P. pallens than reported for the type of P. venustum. Spore length can vary, and we think it is highly likely P. pallens is conspecific with P. venustum. Both were described from the same area in southern Brazil.
Radulodon Ryvarden, Canad. J. Bot. 50: 2073. 1972.
Genus type: Radulodon americanus Ryvarden
Notes: Nakasone & Lindner (2012) showed that most species of Radulodon sensu lato belong to Pseudolagarobasidium instead. As currently recognized, the genus contains 3–4 boreal to temperate species, depending on whether R. americanus is recognized as a separate species. The differences in ITS sequences within the genus are small (Fig. 15).
Fig. 15.
Bayesian consensus tree of Radulodon spp. based on ITS sequences. Countries (and states) of origin are denoted with ISO 3166 codes.
Phylogenetically, Radulodon is a sister genus to Irpiciporus (Fig. 3). We have retained the genus here, though alternatively it would be possible to include it in Irpiciporus. Our reasons relate to the overall generic arrangement of the Cerrenaceae – even though sister taxa, the two are genera are genetically distant (see Results). We suspect our dataset is lacking a lot of species diversity around Radulodon, and hence minimal nomenclatural change is justified until wider genetic and morphological datasets may indicate otherwise.
As defined here, Radulodon is characterized by rather thin, hydnoid basidiocarps as opposed to larger, effused-reflexed found in Acanthodontia and Irpiciporus. Microscopically, cystidia and dense, interwoven subhymenial structure are characteristic. Cystidia are found in Acanthodontia also, but its hyphal structure is consistently looser and more regular as in Irpiciporus, which lacks cystidia. The differences are small, however.
Radulodon casearius (Morgan) Ryvarden, Canad. J. Bot. 50: 2075. 1972.
Basionym: Hydnum casearium Morgan, J. Cincinnati Soc. Nat. Hist. 10: 11, 1887.
Typus: USA, Ohio, Cincinnati, Carya, unknown collection date, A. P. Morgan (holotype BPI US0324642, C. G. Lloyd herb. 16737 – selected by Stevenson & Cash 1936: 74).
Notes: See Nakasone (2001) for a description. Smaller spores separate it from the other species of the genus. This species is known from south temperate United States so far.
Radulodon erikssonii Ryvarden, Canad. J. Bot. 50: 2075. 1972. Fig. 2.
Typus: Norway, Oslo, Sørkedalen, Populus tremula, 24 Oct. 1968, Ryvarden (lectotype O – selected by Nakasone (2001), studied; isotypes in DAOM, L).
Notes: See Eriksson et al. (1981) for a description. ITS sequences of Radulodon americanus and R. erikssonii are nearly identical (2 bp difference in our set of seven sequences). Morphologically, material from North America and Eurasia are indistinguishable; the characters outlined by Ryvarden (1972a) do not separate these species (presence of cystidia, basidiocarp thickness). North temperate to boreal distribution with a continental preference and Populus tremula/tremuloides as a host also join the two. Hence, we consider it likely that R. americanus and R. erikssonii are synonyms, but we would like to see this confirmed with more extensive sampling and several genetic markers. The two species were described in the same paper, but R. erikssonii has been used more widely than R. americanus, and it is included in red lists of several European countries. We recommend therefore maintaining R. erikssonii over R. americanus, if the two are synonymized.
Radulodon yunnanensis Y.C. Dai & Chao G. Wang, Mycol. Progr. 21(73): 11. 2022.
Typus: China, Yunnan, Pingbian, Daweishan Forest Park, Castanea, 5 Jun. 2011, Dai 12204 (holotype BJFC 010487).
Notes: Wang & Dai (2022) described this species from the mountains of Yunnan, China, i.e. eastern Himalayas. It is genetically distinct, but the morphological characters (fimbriate margin, spine density) that the authors list do not separate it from R. erikssonii. Notably, the authors cite one collection from Pinus, while the rest are from angiosperms. This is the only collection of conifer-dwelling Radulodon known to us.
Somion Adans., Familles des plantes 2: 5. 1763.
Genus type: Hydnum occarium Batsch, chosen by Donk (1974: 175).
Etymology: σώμα (Gr., noun) derives from body, torso, flesh, evidently referring to fleshy basidiocarps.
Basidiocarps annual or biennial, sessile to effused-reflexed, light-colored, watery in fresh condition, rather tough after drying. Context duplex, with softer upper and more compact lower layers. Pores angular to sinuous, 1–4 per mm. Hyphal structure monomitic, hyphae clamped and slightly cyanophilous, distinctly thick-walled in both context and trama. Basidia short-clavate, 13–25 × 5–8 μm, four-spored, with guttulate contents, quickly collapsing. Basidiospores ellipsoid or ovoid to subglobose, thick-walled (spore wall up to 1 μm thick), with a large central oil-drop, cyanophilous. Causes a white rot of living and dead deciduous trees.
Notes: Somion is a sister clade to the rest of the Cerrenaceae (Fig. 3). Being so distinct phylogenetically if not morphologically, this clade clearly requires its own genus, whose nomenclature is discussed below. Phylogenetically, the genus is divided in two groups: S. delectans and S. occarium form a clade distinct from the rest. ITS sequences alone are not sufficient to separate all species in the genus, in particular S. formosanum, S. litschaueri, and S. strenuum (Fig. 16). However, TEF1 and the joint TEF1-ITS dataset show clear support for dividing this complex into seven species overall (Fig. 17). For identification of species within the genus, see Table 5.
Fig. 16.
Bayesian consensus phylogram of Somion spp. based on ITS sequences. Countries (and states) of origin are denoted with ISO 3166 codes.
Fig. 17.
Bayesian consensus phylogram of Somion spp. based on ITS and TEF1 sequences. Countries (and states) of origin are denoted with ISO 3166 codes.
Table 5.
Identification table for Spongipellis s.l. All species have slightly thick-walled tramal hyphae and grow on a variety of dicots unless otherwise indicated. Excludes Somion formosanum, which we only know from a sequence from Taiwan. Information for Irpiciporus sinensis from Wang & Dai (2022).
| Species | Distribution | Hosts | Caps | Pores (per mm) | Basidia | Basidiospores (L and W in μm) | Other |
|---|---|---|---|---|---|---|---|
| Aurantiporus s.l. | temperate to tropical | — | Thick, often reddish | Regular, 2–4 | Short | Thin-walled, mid-sized | Tramal hyphae thin-walled, oil abundant |
| Irpiciporus branchiformis | East Africa, tropical | — | Thin, effused | Irpicoid, 2–3 | Long | Slightly thick-walled, L = 5.19, W = 4.69, Q = 1.11 | — |
| Irpiciporus mollis | American Northeast, temperate to subtropical | Preferably Fagaceae | Thin, effused | Irpicoid, 1 | Long | Slightly thick-walled, L = 5.46, W = 4.84, Q = 1.14 | Tramal hyphae thick-walled |
| Irpiciporus pachyodon | Europe and Caucasus, temperate | Preferably Fagaceae | Thin, effused | Irpicoid, 0.5–1 | Long | Slightly thick-walled, L = 6.00, W = 5.14, Q = 1.17 | — |
| Irpiciporus sinuosus | Southeast Asia, subtropical to tropical | — | Thin, reflexed | Sinuous, 4–5 | Long | Slightly thick-walled, L = 5.31, W = 4.42, Q = 1.20 | — |
| Somion delectans | American Northeast, temperate | — | Thick, context duplex | Regular to elongated, 2–3 | Short | Slightly thick-walled, L = 6.61, W = 5.64, Q = 1.18 | Tramal hyphae thick-walled |
| Somion litschaueri | Central Europe, Caucasus, temperate | Quercus | Thick, context duplex, hirsute | Regular to elongated, 1–3 | Short | Thick-walled, L = 7.68, W = 5.96, Q = 1.29 | Tramal hyphae thick-walled |
| Somion occarium | Europe, North Africa, temperate to subtropical | Preferably Fagaceae | Thick, context duplex | Regular to sinuous, 1–3 | Short | Thick-walled, L = 6.60, W = 5.02, Q = 1.32 | Tramal hyphae thick-walled |
| Somion strenuum | East Asia, temperate | Quercus | Thick, context duplex, hirsute | Regular, 3–4 | Short | Thick-walled, L = 5.90, W = 4.80, Q = 1.23 | Tramal hyphae thick-walled |
| Somion tomsovskyi | American Southwest, temperate to subtropical | Quercus | Thick, context duplex, hirsute | Regular, 1–2 | Short | Thick-walled, L = 7.51, W = 6.12, Q = 1.24 | Tramal hyphae thick-walled, interwoven |
| Somion unicolor | American Northeast, temperate | Quercus | Thick, context duplex, hirsute | Regular to sinuous, 1–2 | Short | Thick-walled, L = 6.12, W = 4.78, Q = 1.29 | Tramal hyphae thick-walled |
| Spongipellis ambiens | East Asia, boreal to temperate | Preferably Populus | Rather thick, hirsute | Regular, 4–6 | Rather long | Slightly thick-walled, L = 5.18, W = 4.31, Q = 1.20 | — |
| Spongipellis occidentalis | North America, temperate | Type from Fagus | Thick, hirsute | Regular, 4–6 | Rather long | Slightly thick-walled, L = 6.24, W = 5.00, Q = 1.25 | — |
| Spongipellis profissilis | East Asia, boreal to temperate | Preferably Populus | Thick | Regular, 3–4 | Rather long | Slightly thick-walled, often ovoid, L = 7.31, W = 5.24, Q = | — |
| 1.41 | |||||||
| Spongipellis spumea | Europe, temperate | — | Thick, hirsute | Regular, 3–4 | Rather long | Slightly thick-walled, L = 6.14, W = 5.02, Q = 1.23 | — |
| Spongipellis variispora | East Asia, temperate | Preferably Ulmus | Thick, hirsute | Regular, 4–6 | Rather long | Slightly thick-walled, L = 6.24, W = 5.29, Q = 1.19 | — |
Dismantling traditional, morphology-based genera requires not only a re-consideration of their younger synonyms (e.g. Irpiciporus in the case of Spongipellis sensu lato) but also a careful revision of suppressed older names. Recent DNA-based revisions of the corticioid genera Hyphodontia and Tomentella, both conserved versus their older synonyms, made it necessary to restore some suppressed generic names (e.g., Kneiffiella, Odontia, and Xylodon). This restoration is allowed if the type species of the conserved and the suppressed genus cannot be anymore considered congeneric (ICN Shenzhen code art. 14.6). In the case of Spongipellis, the older name which requires further examination is Somion Adans. against which Spongipellis has been conserved (ICN Appendix III). We show below that the type species of Somion cannot belong to Spongipellis sensu stricto (Meripilaceae), and thus the name is available for use and must be considered when Spongipellis sensu lato is being divided into several genera.
The genus Somion was described by Adanson (1763: 5) based on three illustrations published by Micheli (1729: Tabula 64, figs 3–5). No binomial species names were addressed to the genus in the protologue; nevertheless, Somion meets the requirements for a validly published generic name (see Donk 1960: 283). The name may have gone unnoticed because Ryvarden’s index to generic names does not contain it (Ryvarden 1991). The three aforementioned Micheli’s figures were the basis for the subsequent introduction of four species names: Hydnum occarium Batsch (fig. 3 – Batsch (1783: 113), sanctioned by (Fries 1821: 412), H. orbiculatum Pers. (fig. 5 – Persoon 1801: 559), sanctioned by Fries (1821: 412) and H. pectinatum Fr. (fig. 4 – Fries 1821: 412). Batch’s H. pectiniforme is based on figs 4 and 5, but Fries considers it as a synonym of H. orbiculatum, so the latter as a conserved name has priority over the former and H. pectiniforme is obsolete.
Donk (1974: 175) selected H. occarium as a lectotype of Somion (at that time a devalidated generic name) and treated it as a synonym of Spongipellis – he had suggested earlier that H. occarium might be a synonym of Spongipellis pachyodon (Donk 1960: 176). Changing the starting point for validly published fungal genera from 1821 to 1753 (ICBN Sydney code 1981) made Somion available for use although under the aforementioned condition only. The identity of H. occarium decides whether Somion is going to be kept as a suppressed synonym of Spongipellis or whether it should be put in use as an independent genus.
The protologue by Batsch (1783) and the subsequent redescription of H. occarium by Fries (1821) introduced it as a white, large fungus with hairy upper surface and flat, thick and blunt “aculei”; additionally, Fries describes the consistence of H. occarium as “probably fleshy” (‘substantia … forsan carnosa’), and size being 3 inches wide and projecting 1–1.5 inches. The generic name Somion refers to a fleshy fungus, which may be the origin of Fries’s statement. The measurements probably derive from Persoon (1801). Micheli’s drawing, which may serve as a lectotype of the species (ICN art. 9.3, 9.4), shows three pileate, mid-sized caps with something like irpicoid or blunt hydnoid hymenophore viewed from the side.
There are not many non-stipitate pileate, light-coloured hydnoid-irpicoid fungi in Europe. Climacodon septentrionalis, Donkia pulcherrima, and Hericium cirrhatum have sharp, rather small teeth in contrast to descriptions of Batsch (1783) and Fries (1821). Old caps of Cerrena unicolor may be irpicoid but then also grey, not light-coloured, and caps are rather thin. Irpex lacteus, Irpicodon pendulus, and Steccherinum oreophilum fruiting bodies are much too small to fit the description. Trametopsis cervina has daedaleoid pores that may turn irpicoid, but its caps are usually quite thin, projecting less than described, and not fleshy, so this species is not the most likely candidate either.
Turning to Spongipellis, the hymenophore construction precludes the two European species of Spongipellis sensu stricto, S. profissilis and S. spumea (Spirin et al. 2022). They both possess normal poroid hymenophore, which cannot be interpreted as having tooth-like appearance, and thus synonymy of Somion and Spongipellis is excluded. The illustration and description of the hymenophore would fit well to Spongipellis (Irpiciporus) pachyodon. However, all the specimens we have seen have smooth (or near so) pileal surface, and this seems to be the case in the literature as well: Bernicchia (2005) describes the upper surface as tomentose to smooth, and Rivoire (2020) as cottony to felt-like. The relatively small size of caps in S. pachyodon does not fit the descriptions of H. occarium either.
The European taxon so far called S. delectans but proven to represent a good species in this study, is yet another option. It has nearly white, substantial basidiocarps with often strigose pileal surface (Fig. 1E) and large, irregular pores that may become dentate (described as irpicoid by Bernicchia 2005 and Rivoire 2020). Micheli, Batsch, and Fries (who apparently never saw specimens) might have described such a hymenophore as consisting of blunt teeth. We find the European S. delectans as the most credible option for typifying H. occarium in that it does not contradict any element of the protologue and agrees well in many. Consequently, we designate here an epitype to supplement the lectotype illustration among the European material of S. delectans.
As a result, Somion becomes the oldest name available for the S. delectans complex, which requires its own genus. The correct species name of European S. delectans is then Somion occarium (Batsch) Spirin & Miettinen.
Somion delectans (Peck) Vlasák & Spirin, comb. nov. MycoBank MB 849651. Fig. 18.
Fig. 18.
Spores of Somion spp. and hyphal structure, tube trama, with subhymenium and hymenium, of S. strenuum (holotype).
Basionym: Polyporus delectans Peck, Bull. Torrey Bot. Club 11: 26. 1884.
Typus: USA, Ohio, Cincinnati, fallen log, unknown collection date, Morgan 106 (holotype NYS, isotype BPI US 0207202, studied).
Basidiocarps annual, sessile or effused-reflexed, up to 15 cm in widest dimension. Upper surface finely pubescent, later almost smooth, azonate, cream coloured to pale ochraceous. Edge of pileus sharp to rather blunt, sterile, concolourous with pileal surface. Hymenial surface even to more-or-less concave or rarely convex, cream coloured to pale ochraceous; pores angular to somewhat elongated, 2–3 per mm, dissepiments rather thin, first even, later serrate. Section: context white to cream coloured or pale ochraceous (old herbarium specimens only), watery in fresh condition, firm, indistinctly fibrillose and azonate when dry, up to 1 cm thick; tube layer soft, concolourous with pore surface, up to 1 cm thick.
Hyphal structure monomitic; all hyphae with clamp connections. Context hyphae very thick-walled, arranged in subparallel bundles, a few thin-walled, (4.1–)4.7–6.2(–7.7) μm diam. Tramal hyphae thick-walled (lumen capillary to indistinct), subparallel, (3.2–)3.8–4.7(–5.2) μm diam. Subhymenial hyphae more or less thin-walled, 2.7–4.0 μm diam. Basidiospores thick-walled, broadly ellipsoid to subglobose, (5.8–)6.0–7.3(–7.6) × (5.0–)5.1–6.6(–6.8) μm, L = 6.6 μm, W = 5.64 μm, Q = 1.16–1.19.
Distribution and ecology: Found in temperate forests in the eastern part of North America, uncommon. Occurs on still standing trees and fallen logs of various angiosperms.
Notes: Morphologically, S. delectans is the most similar to the European S. occarium. Both species share sessile or effused-reflexed, rather thin and pale coloured (compared with other Somion species) basidiocarps. However, pores of S. delectans are not as irregular in size and shape as in S. occarium, and on average smaller, 2–3 per mm. Moreover, basidiospores of the first species are slightly wider than in S. occarium although these differences are merely statistical.
Polyporus delectans was described from Ohio (Peck 1884) and later reported from the US Northeast and adjacent parts of Canada (Lowe 1975, as Tyromyces delectans). It inhabits living and fallen deciduous trees from many genera (Gilbertson & Ryvarden 1987). Its earlier records from the Pacific Northwest and Alaska should be confirmed.
Somion formosanum (T.T. Chang & W.N. Chou) Miettinen & Vlasák, comb. nov. MycoBank MB 849652.
Basionym: Tyromyces formosanus T.T. Chang & W.N. Chou, Mycol. Res. 103: 675. 1999.
Typus: Taiwan, Nantou, Meifeng, hardwood, Dec. 1997, Chou TFRI c2873 (holotype “TAIF”).
Notes: This species was described as a member of Tyromyces, at that time a collective genus for all fleshy mono/dimitic polypores causing a white rot. ITS and TEF1 sequences show that T. formosanus is a member of Somion and does not belong to any other species of the genus recognized here. The type is supposedly stored in the herbarium TAIF of the Taiwan Forest Research Institute, where Dr T.T. Chang worked. We wrote to TAIF requesting the type on loan in 2016 – so 17 years after the publication of the species – but were informed that no fungal material is stored in the herbarium. The herbarium staff suggested that the type specimen may still be with Dr Chang, who never replied to us. Under these circumstances, we were not able to get the type on loan. According to the original description (Chang & Chou 1999), S. formosanum is morphologically the most similar to S. unicolor. However, DNA data indicate that it is more closely related to S. litschaueri and S. strenuum. So far, S. formosanum is known only from two collections from the type locality.
Somion litschaueri (Lohwag) Vlasák & Spirin, comb. nov. MycoBank MB 849653. Fig. 18.
Basionym: Spongipellis litschaueri Lohwag, Arch. Protistenk. 75: 301, 1931.
Typus: Austria, Burgenland: Sankt Margarethen im Burgenland, broken standing tree of Quercus sp., Oct. 1930, K. Jusa (holotype W 0132387, studied).
Basidiocarps annual, sessile, pilei projecting up to 10 cm. Upper surface tomentose to hirsute, azonate, yellowish to pale or bright ochraceous. Edge of pileus blunt, sterile, concolourous with pileal surface. Hymenial surface even to more-or-less convex, cream coloured to ochraceous or pale brown; pores angular to irregularly elongated, 1–3 per mm, dissepiments rather thick, first more or less even, later serrate. Section: context white to cream coloured or pale ochraceous (old herbarium specimens only), watery in fresh condition, firm, distinctly fibrillose and zonate when dry, up to 3 cm thick; tube layer tough, concolourous with pore surface, up to 3 cm thick.
Hyphal structure monomitic; all hyphae with clamp connections. Context hyphae very thick-walled, interwoven or arranged in subparallel bundles, (3.9–)4.8–5.8(–7.4) μm diam. Tramal hyphae thick-walled (lumen narrow to rather wide), subparallel, (2.8–)3.2–4.1(–5.2) μm diam. Subhymenial hyphae slightly thick-walled, 2.0–2.5 μm diam. Basidiospores thick-walled, broadly ellipsoid to ovoid, (6.6–)6.8–8.6(–9.1) × (4.9–) 5.2–7.0(–7.7) μm, L = 7.71 μm, W = 6.00 μm, Q = 1.27–1.33.
Distribution and ecology: Widely distributed in Central Europe although rare. Inhabits old living and recently fallen logs of Quercus spp., especially Q. cerris (Kotlaba & Pouzar 1965).
Notes: This species was described from Austria (Lohwag 1931, as Spongipellis litschaueri) and later reported from several countries of Central Europe (summarized in Tomšovský 2012). Another Somion species from Europe, S. occarium, differs from S. litschaueri in having thinner and paler, often effused-reflexed basidiocarps, sinuous pores, wider tramal hyphae and smaller basidiospores. Older records of S. litschaueri from European part of Russia, Ukraine, and Caucasus (Bondartsev 1953) should be reconfirmed.
Somion occarium (Batsch) Spirin & Miettinen, comb. nov. MycoBank MB 849654. Figs 1, 18.
Basionym: Hydnum occarium Batsch, Elenchus fungorum: 113. 1783 (conserved by Fries 1821: 412).
Synonyms: Spongipellis suberis Pat., Catalogue Raisonné des Plantes Cellulaires de la Tunisie 7: 48. 1897.
Leptoporus bredecelensis Pilát ex Pilát, Acta Musei Nat. Pragae 9B(2): 103. 1953.
Typus: Micheli, Nova plantarum genera: table 64, fig. 3, 1729 (lectotype of Hydnum occarium selected here, MBT 10014533). Czech Republic, Jihomoravský kraj, Břeclav, Valtice, 48.74931 16.79226, dead, uprooted Quercus cerris, 18 Nov. 2005, Vlasák* (epitype of Hydnum occarium designated here H 7200694, MBT 10014534, studied, isoepitype JV 0511/8). Tunisia, El Fedja, Quercus suber, Jan. 1893, herb. Patouillard (lectotype of Spongipellis suberis FH, studied – selected by Ryvarden 1983). Ukraine, Zakarpatska Reg., Dilove, Mt. Menchul, Fagus sylvatica, Aug. 1934, Pilát (holotype of Leptoporus bredecelensis PRM 623854, studied).
Basidiocarps annual, sessile or effused-reflexed, up to 10 cm in widest dimension. Upper surface finely pubescent, sometimes indistinctly warted or striate, later almost smooth, azonate, cream coloured to pale ochraceous. Edge of pileus sharp to rather blunt, sterile, concolourous with pileal surface. Hymenial surface even to more or less concave or rarely convex, almost white to cream coloured; pores angular to sinuous, 1–3 per mm, dissepiments rather thin, serrate to dentate. Section: context white to cream coloured or pale ochraceous (old herbarium specimens only), watery in fresh condition, firm, indistinctly fibrillose and azonate when dry, up to 1 cm thick; tube layer soft, concolourous with pore surface, up to 2 cm thick.
Hyphal structure monomitic; all hyphae with clamp connections. Context hyphae very thick-walled, arranged in subparallel bundles, (4.2–)5.0–6.3(–10.4) μm diam. Tramal hyphae thick-walled to more rarely slightly thick-walled (lumen distinct to capillary), subparallel, (3.0–)3.6–4.7(–5.4) μm diam. Subhymenial hyphae thin-walled, 3–4 μm diam. Basidiospores thick-walled, broadly ellipsoid to ovoid, a few subglobose, (5.3–) 6.0–7.2(–7.6) × (3.9–)4.3–5.5(–6.2) μm, L = 6.60 μm, W = 5.02 μm, Q = 1.28–1.37
Distribution and ecology: Somion occarium inhabits many deciduous trees, both living and already dead but it seems to prefer Fagus (Ryvarden & Gilbertson 1994, as S. delectans). Its distribution stretches from the Mediterranean in the south to the southern part of Sweden in the north.
Notes: See remarks under the genus for nomenclatural details. Somion occarium is the European counterpart of North American S. delectans. Differences between these species are listed under the latter species.
Somion strenuum Spirin & Vlasák, sp. nov. MycoBank MB 849655. Figs 1, 18.
Typus: Russia, Khabarovsk Reg., Solnechnyi Dist., Sonakh, 51.450 : 135.321, alt. 230 m, low, bushy oak forest with fire history, on living Quercus mongolica (basal diameter 20 cm), 15 Aug. 2014, Spirin 7330* (holotype H 7200353).
Etymology: Strenuus (Lat., adj.) – strenuous, tough.
Basidiocarps annual or short-living perennial, sessile, pilei projecting up to 12 cm. Upper surface tomentose to hirsute, azonate, yellowish to pale ochraceous, in oldest parts fading to grey. Edge of pileus blunt, sterile, concolourous with pileal surface. Hymenial surface even to more or less concave, yellowish to pale ochraceous; pores angular, 3–4 per mm, dissepiments rather thick, uneven to serrate. Section: context cream coloured to pale ochraceous, watery in fresh condition, firm, indistinctly fibrillose and zonate when dry, up to 3 cm thick; tube layer tough, indistinctly stratified, concolourous with or slightly paler than pore surface, up to 2 cm thick.
Hyphal structure monomitic; all hyphae with clamp connections. Context hyphae very thick-walled, interwoven or in subparallel bundles, (3.3–)4.2–5.1(–6.3) μm diam. Tramal hyphae very thick-walled (lumen capillary to indistinct), subparallel, (2.7–)3.2–3.8(–4.2) μm diam. Subhymenial hyphae thin- to slightly thick-walled, 3–4 μm diam. Basidiospores thick- walled, ellipsoid to broadly ellipsoid, (5.0–)5.2–6.4(–7.2) × (4.1–) 4.2–5.3(–6.0) μm, L = 5.90 μm, W = 4.80 μm, Q = 1.19–1.26.
Distribution and ecology: Somion strenuum is distributed in temperate East Asia and restricted to Quercus spp. Lyubarsky & Vassilieva (1975) treated this species (as S. litschaueri) from oak forests and plantations in Russian Far East, where it attacks living, often rather young trees of Q. mongolica.
Notes: Somion strenuum has the smallest pores in the whole genus. Microscopically, it is the most similar to the North American S. unicolor, which has much larger pores.
Somion tomsovskyi (Nakasone & Ortiz-Santana) Vlasák & Spirin, comb. nov. MycoBank MB 849656. Figs 1, 18.
Basionym: Pseudospongipellis tomsovskyi Nakasone & Ortiz- Santana, Lilloa 59 (Suppl.): 104. 2022.
Typus: USA, Arizona, Cochise County, Coronado National Forest, Chiricahua Mountains, Rucker Canyon, on Quercus emoryi, 27 Oct. 1967, Gilbertson 7701 (holotype ARIZ AN010813; isotype CFMR).
Basidiocarps annual, sessile, pilei projecting up to 10 cm. Upper surface tomentose to hirsute, azonate, yellow to pale ochraceous, in oldest parts fading to grey. Edge of pileus blunt, sterile, concolourous with pileal surface. Hymenial surface even to more-or-less convex, yellow to pale ochraceous; pores angular, 1–1.5 per mm, dissepiments thick, uneven to serrate. Section: context cream coloured to pale ochraceous, in old herbarium specimens pale brown, watery in fresh condition, firm, distinctly fibrillose and zonate when dry, up to 4 cm thick; tube layer tough, concolourous with or slightly paler than pore surface, up to 2 cm thick.
Hyphal structure monomitic; all hyphae with clamp connections. Context hyphae very thick-walled, rather loosely interwoven, a few arranged in subparallel bundles, (3.1–)3.6– 4.7(–5.3) μm diam. Tramal hyphae slightly or distinctly thick- walled (lumen wide to narrow), densely interwoven, (3.2–)3.8– 4.8(–5.1) μm diam. Subhymenial hyphae thin- to slightly thick- walled, 3–5 μm diam. Basidiospores thick-walled, ellipsoid to broadly ellipsoid, (6.4–)6.8–8.3(–8.7) × (5.1–)5.5–6.8(–7.1) μm, L = 7.5 μm, W = 6.11 μm, Q = 1.22–1.23.
Distribution and ecology: So far known from the US Southwest and adjacent areas of Mexico inhabiting living and recently dead logs of Quercus spp.
Notes: Somion tomsovskyi is a close relative of S. unicolor. These species differ primarily in their distribution areas (US Southwest and Mexico vs. the North American Northeast). Microscopically, S. tomsovskyi differs from the rest of Somion species in having interwoven (not subparallel) tramal hyphae with a well-visible lumen. Two other species from North America, S. delectans and S. unicolor, have smaller basidiospores. Description and spore measurements of S. unicolor given by Gilbertson & Ryvarden (1987) refer to S. tomsovskyi.
Somion unicolor (Fr.) Spirin & Miettinen, comb. nov. MycoBank MB 849657. Fig. 18.
Basionym: Polyporus unicolor Fr., Epicrisis Systematis Mycologici: 458. 1838.
Synonym: Boletus unicolor Schwein., Schriften der Naturforschenden Gesellschaft zu Leipzig 1: 97. 1822.
Typus: USA, North Carolina, Salem (lectotype of Polyporus unicolor selected here PH 00063495, MBT10014535, photo studied in plants. jstor.org).
Basidiocarps annual, sessile, pilei projecting up to 10 cm. Upper surface tomentose to hirsute, azonate, yellowish to pale ochraceous, in oldest parts fading to pale grey. Edge of pileus blunt, fertile, concolourous with pileal surface. Hymenial surface even to more-or-less convex, yellowish to pale ochraceous or brownish; pores angular to sinuous, in largest basidiocarps with a tendency to radial arrangement, 1–1.5 per mm, dissepiments thick, serrate to dentate. Section: context cream coloured to pale ochraceous, in old herbarium specimens pale brown, watery in fresh condition, firm, distinctly fibrillose and zonate when dry, up to 2 cm thick; tube layer tough, concolourous with or slightly paler than pore surface, up to 3 cm thick.
Hyphal structure monomitic; all hyphae with clamp connections. Context hyphae very thick-walled, arranged in subparallel bundles, (3.7–)4.2–5.3(–6.2) μm diam. Tramal hyphae very thick-walled (lumen capillary), subparallel, (3.4)–4.0–4.7(–5.3) μm diam. Subhymenial hyphae thin- to slightly thick-walled, some inflated, 3–6 μm diam. Basidiospores thick-walled, ellipsoid to ovoid, (5.2–)5.3–7.1(–7.3) × (4.0–)4.2–5.4(– 5.9) μm, L = 6.13 μm, W = 4.78 μm, Q = 1.22–1.34.
Distribution and ecology: Widely distributed in the North- American Northeast inhabiting still living or recently dead trees of Quercus spp.
Notes: Schweinitz (1822) described Boletus unicolor from North Carolina. This name is invalid due to Boletus unicolor Bull. 1789. Fries (1836–1838), however, technically validated the name when he treated it as Polyporus unicolor, and should be cited as the valid author of the species. Schweinitz’s protologue does not mention specimens. We select the single collection from the Schweinitz herbarium in PH as the lectotype. The basidiocarp is thick and with initially regular pores that split with age, 5–10 pores per cm (median 7), i.e., 0.5–1 per mm. The two other Somion species in North America do not come into question: S. tomsovskyi is not found in the east coast, and S. delectans has smaller, less regular pores and thinner fruiting bodies. Thus, the lectotype agrees with the modern concept of the species.
Somion unicolor has been reported from many localities in the US Northeast and adjacent part of Canada (Lowe 1975). It seems to be restricted to Quercus spp. Earlier records of S. unicolor from the US Southwest belong to S. tomsovskyi (see above). Somion delectans, sharing the same distribution area with S. unicolor, differs from it in having thinner, often effused-reflexed basidiocarps, smaller pores and wider basidiospores.
Excluded and insufficiently known species
Cerrena maxima (Mont.) L. Hansen, Nat. Hist. Renell Isl. Solomon Isls: 129. 1960.
Synonym: Trametes maxima (Mont.) A. David & Rajchenb., Mycotaxon 22: 315. 1985.
Typus: Cuba, de la Sagra (holotype of Trametes maxima PC, herb. Montagne 1413, studied).
Notes: Ryvarden & Johansen (1980) retained this and the two following species in Cerrena. Trametes maxima is a typical member of Trametes.
Cerrena meyenii (Klotzsch) L. Hansen, Nat. Hist. Renell Isl. Solomon Isls: 129. 1960.
Synonym: Trametes meyenii (Klotzsch) Lloyd, Mycological Writings 5(67): 14. 1918.
Notes: While this species has been placed in Cerrena, our morphological analysis and preliminary sequence data place it in the Polyporaceae. For now, Trametes is the best available genus for it.
Cerrena sclerodepsis (Berk.) Ryvarden, Mem. New York Bot. Gard. 28: 204. 1976.
Basionym: Trametes sclerodepsis Berk., Hooker’s J. Bot. Kew Gard. Misc. 8: 236. 1856.
Notes: Our morphological analysis and preliminary sequence data place this species in the Polyporaceae. For now, Trametes is the best available genus for it.
Irpiciporus africanus (Ipulet & Ryvarden) Nakasone, Lilloa 59 (Suppl.): 94. 2022.
Basionym: Spongipellis africana Ipulet & Ryvarden, Syn. Fungorum 20: 97. 2005.
Hypochnicium africanum (Ipulet & Ryvarden) Miettinen, comb. nov. MycoBank MB 849658.
Typus: Uganda, Kanungu, Bwindi Impenetrable NP, Byumba, rotting log, 24 May 2003, Ipulet F1683* (holotype of Spongipellis africana O, studied).
Notes: This species with hydnoid, effused-reflexed basidiocarps has septate cystidia and thick-walled, cyanophilous spores. It does not belong to the Cerrenaceae or Spongipellis s. str. Micromorphology and nrDNA sequence of the type specimen point towards Hypochnicium and not to S. pachyodon (i.e. Irpiciporus) as suggested by Ipulet & Ryvarden (2005) and Nakasone & Ortiz-Santana (2022). In the scheme of Maekawa et al. (2023), the species might belong to Gyrophanopsis or to a genus of its own, but we prefer a larger concept of Hypochnicium for now, including Gyrophanopsis and H. africanum.
Irpiciporus cubensis (Berk. & M.A. Curtis) Murrill, N. Amer. Fl. 9: 15. 1907.
Basionym: Irpex cubensis Berk. & M.A. Curtis, J. Linn. Soc., Bot. 10: 326. 1869.
Typus: Cuba, summit of Lomo del Gaso, on rotting logs, unknown collection date, Wright 240, Fungi Cubensis Wrightiani no. 355 (lectotype K – selected by Maas Geesteranus 1974: 470, isotype FH 00301398).
Notes: Description of the type were given by Maas Geesteranus (1974) and Nakasone & Ortiz-Santana (2022). According to their descriptions, the type is small and sterile, with unclear affinity. Maas Geesteranus specifically excludes conspecificity with Cerrena zonata and notes the specimen is irpicoid, dimitic, with clamped septa and oil-filled hyphal ends. Nakasone and Ortiz- Santana add that cylindrical cystidia (or oil hyphae) project from the hymenium. We have not seen the type, but it seems unlikely that it belongs to any genus treated here.
Irpiciporus decolorans (Cooke) Nakasone, Lilloa 59 (Suppl.): 95. 2022.
Basionym: Irpex decolorans Cooke, Grevillea 19(92): 109. 1891.
Typus: Cuba, on rotting logs, unknown collection date, C. Wright 835 (lectotype K(M) 62571 – selected by Maas Geesteranus 1974: 471).
Notes: Nakasone (2012) and Nakasone & Ortiz-Santana (2022) provide descriptions of the type, which we have not studied here. According to them, the type is richly fertile though the hymenium is degraded. Nakasone & Lindner (2012) describe a dense structure of agglutinated hyphae, small ellipsoid spores, brown colour and relatively short, and small spines. They placed it in Cristinia (Agaricales). Nakasone & Ortiz-Santana (2022) place the species in Irpiciporus and state that the basidiomes “change from white to brown on drying”. Where this information comes from is unclear, since already Cooke in the protologue describes the caps as sooty, i.e. dirty brown (“fuligineus”). These characters make it highly unlikely that this species belongs to Irpiciporus with white, rather big basidiomes and open structure. Hjortstam & Larsson (1995) suggest this species is related to Radulodon, though Nakasone does not describe cystidia as present in Radulodon spp. Ryvarden (2020b) claims it represents Cerrena zonata, a dimitic species. These opinions are all conflicting and the identity of this species remains ambiguous.
Irpiciporus lacteus (Fr.) Murrill, North American Flora 9: 15. 1907.
Synonym: Irpex lacteus (Fr.) Fr., Elenchus Fungorum 1: 145. 1828.
Note: This type species of Irpex belongs to Irpicaceae, Polyporales (Justo et al. 2017).
Irpiciporus noharae Murrill, Mycologia 1: 166. 1909.
Synonym: Lopharia mirabilis (Berk. & Broome) Pat., Bull. Soc. Mycol. France 11: 14. 1895.
Notes: Nakasone & Ortiz-Santana (2022), who studied the type, conclude it represents Lopharia mirabilis, a distinctive species in the Polyporaceae. This is also the conclusion of Ryvarden (2020b).
Irpiciporus rajchenbergii Nakasone, Lilloa 59 (Suppl.): 95. 2022.
Typus: Brazil, São Leopoldo, 1931, Rick (holotype BPI 0259635).
Notes: Nakasone described this species without sequence data and based on an old specimen of Rick from southern Brazil (Nakasone & Ortiz-Santana 2022). The description points towards Irpiciporus, but since her concept of the genus is heterogeneous, another opinion on its identity would be desirable.
Irpiciporus tanakai Murrill, Mycologia 1: 167. 1909.
Synonym: Antrodia tanakae (Murrill) Spirin & Miettinen, [as ’tanakai’], Mycologia 105: 1572. 2013 [2014].
Note: This species belongs to Antrodia sensu stricto (Fomitopsidaceae, Polyporales; Spirin et al. 2013).
Irpiciporus tulipiferae (Schwein.) Murrill, Bull. Torrey Bot. Club 32: 472. 1905.
Synonym: Irpex lacteus (Fr.) Fr., Elenchus Fungorum 1: 145. 1828.
Note: Maas Geesteranus (1974) showed the type belongs to Irpex lacteus.
Irpiciporus xuchilensis (Murrill) Y.C. Dai & Chao G. Wang, Mycol. Progr. 21(73): 8. 2022.
Basionym: Coriolus xuchilensis Murrill, Bull. New York Bot. Gard. 8: 143, 1912.
Bjerkandera xuchilensis (Murrill) Miettinen, comb. nov. MycoBank MB 849659.
Typus: Mexico, Veracruz, Xuchiles, near Cordoba along Rio Blanco, 17 Jan. 1910, WA & EL Murrill 1171 (holotype of Coriolus xuchilensis NY 00705008, studied).
Notes: Zhao et al. (2017) and Wang & Dai (2022) published Irpiciporus sequences of one Ecuadorian specimen under this name (GenBank KX161650, KX161659). Those sequences are unique among the available sequences, so this specimen represents another species in the genus Irpiciporus. However, the correct name is not I. xuchilensis. We have studied the type of C. xuchilensis. It clearly belongs to Bjerkandera, though it is beyond the scope of this paper to determine to which of the currently recognized species in that genus. New species of Bjerkandera have been recently described from tropical Americas, and they should be reviewed against this older species name. Coming back to the Irpiciporus specimen, we leave it formally without a name, since we consider it possible that older names may exist for it for instance among the species Murril described.
Polyporus albostygius Berk. & M.A. Curtis, J. Linn. Soc., Bot. 10: 309. 1869.
Synonym: Rigidoporus albostygius (Berk. & M.A. Curtis) Rajchenb., Revista de Investigaciones Agropecuarias Serie 5, Patología vegetal: 72. 1984.
Typus: Cuba, unknown collection date, Wright 583 (K – lectotype of Rigidoporus albostygius designated by Ryvarden (1984), isotype FH 290626, studied).
Note: Though sometimes listed as a synonym of Lividopora vincta, this species belongs to Meripilaceae.
Polyporus bistratosus Berk. & Cooke, J. Linn. Soc. Bot. 15: 384. 1877.
Typus: Brazil, Amazon, Paricatuba, River Purua, 8 Sep. 1974, Trail 74 (holotype K(M) 192256, studied).
Notes: Another species sometimes listed as a synonym of L. vincta. It belongs to Meripilaceae.
Polyporus hyposclerus Berk. ex Cooke, Grevillea 10(55): 103. 1882.
Typus: Australia, Queensland, Brisbane, unknown collection date, Broome (holotype K(M) 192252, studied).
Notes: A supposed synonym of L. vincta. The type is sterile and in bad condition, but it is a species of Fomitopsis.
Pseudolagarobasidium calcareum (Cooke & Massee) Sheng H. Wu, Acta Bot. Fenn. 142: 112. 1990.
Notes: Nakasone & Lindner (2012) suggested that this species is a synonym of P. pronum described from Sri Lanka. Its status as a separate species should be revised; see further notes under P. pronum.
Pseudolagarobasidium concentricum (Cooke & Ellis) Hjortstam, Mycotaxon 54: 190. 1995.
Synonym: Pirex concentricus (Cooke & Ellis) Hjortstam & Ryvarden, Mycotaxon 24: 289. 1985.
Note: This North American species is the type of Pirex and belongs to Phanerochaetaceae (Polyporales; Justo et al. 2017).
Pseudolagarobasidium conspicuum (Pouzar) Nakasone, Mycotaxon 130: 378. 2015.
Basionym: Hyphoradulum conspicuum Pouzar, Česká Mykol. 41: 26. 1987.
Crustomyces conspicuus (Pouzar) K.H. Larss., comb. nov. MycoBank MB 849660.
Typus: Czech Republic, Central Bohemia, Karlštejn, Velka Hora, Cornus mas, 2 Oct. 1981, Pouzar (holotype of Hyphoradulum conspicuum PRM 834886; isotype GB*, studied).
Notes: This is the type species of the monotypic genus Hyphoradulum Pouzar. Nakasone (2015) placed it in Pseudolagarobasidium. We managed to generate an ITS sequence from an isotype deposited in herb. GB. BLAST searches against GenBank showed close affinity with Crustomyces, which belongs to Cystostereaceae, Agaricales. Li et al. (2022) recently published a phylogenetic analysis of Cystostereaceae. We conducted a phylogenetic analysis of the ITS region from a selection of the dataset used in Li et al. along with the H. conspicuum sequence and a few new Crustomyces sequences (Fig. 19). Hyphoradulum conspicuum was recovered as a sister taxon to Crustomyces tephroleucus within a strongly supported clade corresponding to the expanded genus concept of Crustomyces introduced by Li et al. (2022). This wider Crustomyces includes Cystidiodontia (type Cystidiodontia artocreas = C. laminifera) and Rigidotubus (type Rigidotubus tephroleucus). We follow this circumscription of Crustomyces and suggest that also Hyphoradulum should be placed there.
Fig. 19.
Bayesian consensus phylogram of Cystostereaceae based on ITS sequences. Countries (and states) of origin are denoted with ISO 3166 codes.
Radulodon acaciae G. Kaur, Avneet P. Singh & Dhingra, Mycotaxon 127: 111. 2014.
Notes: This species likely belongs to Pseudolagarobasidium, and Nakasone & Ortiz-Santana (2022) considered it a synonym of P. acaciicola based on the original description. In our view the protologue (Kaur et al. 2014) is not sufficient to make any firm conclusions about its identity.
Radulodon americanus Ryvarden, Canad. J. Bot. 50: 2074. 1972.
Typus: Canada, British Columbia, Prince George, Populus tremuloides, 25 Aug. 1945, Foster (holotype DAOM 16599, studied).
Note: Type species of Radulodon, but possibly a synonym of R. erikssonii, see remarks under that species.
Radulodon copelandii (Pat.) N. Maek., Rep. Tottori Mycol. Inst. 31: 93. 1993.
Synonym: Radulomyces copelandii (Pat.) Hjortstam & Spooner, Kew Bulletin 45: 314. 1990.
Notes: This species described from the Philippines belongs to Radulomyces (Nakasone 2001). Nakasone et al. (2021) provide sequences under this name from southern China.
Radulodon indicus Jyoti & Dhingra, Syn. Fungorum 32: 38. 2014.
Notes: Described from Jammu, India. Its authors compare the species to Radulodon pseudomucidus, which is a synonym of Radulomyces copelandii (Nakasone et al. 2021). We have not seen material, but the description points towards Radulomyces.
Radulodon licentii (Pilát) Ryvarden, Česká Mykol. 30(1): 40. 1976.
Synonym: Radulomyces licentii (Pilát) Parmasto, Conspectus Systematis Corticiacearum: 111. 1968.
Note: Nakasone et al. (2021) accept this species described from North China in Radulomyces (Agaricales) and provide DNA data from Southwest China and Taiwan.
Radulodon pseudomucidus (Petch) Stalpers, Folia Cryptog. Estonica 33: 137. 1998.
Note: Nakasone et al. (2021) consider this a synonym of Radulomyces copelandii (Agaricales).
Radulodon subquercinus (Henn.) Hjortstam & Ryvarden, Mycotaxon 10: 285. 1980.
Notes: Type of the genus Phaneroites, this acystidiate species reminds Phanerochaete sensu lato and does not belong to the Cerrenaceae. Hjortstam (1987) considered Phanerochaete radulans Hallenb. a synonym.
Rigidoporus hypobrunneides Corner, Beih. Nova Hedwigia 86: 165. 1987.
Typus: Malaysia, Pahang, Cameron Highland, 31 Jul. 1934, Corner (holotype E 00159712, photograph studied).
Notes: As the name indicates, Corner (1987) considers this species similar to R. hypobrunneus (= Lividopora benetosta). He mentions that it has bigger pores, which brings Lividopora facilis to mind. We have not studied the type under microscope, but the photograph is of a light-colored resupinate polypore, whose mid-sized tubes have turned partly brown. Corner mentions that R. hypobrunnea has thick-walled, heavily encrusted cystidia (“extrahymenial setae”), while he only mentions thin-walled, narrow cystidia in R. hypobrunneides. This tells us that R. hypobrunneides is not a species of Lividopora and certainly not an older name for L. facilis. It could rather be a member of the Meripilaceae. Hattori (2001), who studied the type, mentions that it is moldy, indicating that Corner’s spore measurements may refer to mold spores. Hattori left the specimen as Rigidoporus sp.
Spongipellis caseosa (Pat.) Ryvarden, Occas. Pap. Farlow Herb. Cryptog. Bot. 18: 11. 1983.
Basionym: Leptoporus caseosus Pat., Ann. Mycol. 5(4): 365. 1907.
Typus: Brazil, São Paulo, Caminas, Mar. 1897, Noack (lectotype FH 00258975, studied – typified by Ryvarden 1983).
Notes: Light-coloured, monomitic with thick-walled generative hyphae, spores slightly cyanophilous and slightly thick-walled, ellipsoid. Hymenium has collapsed in the type. These characters may imply Somion, but we cannot exclude Ryvardenia. Spores are smaller than in the described species of Ryvardenia (Rajchenberg 1994) or Somion. Modern collections and/or revision of the type material are needed to confirm its identity.
Spongipellis eberhardtii Pat., Bull. Soc. Mycol. France 36: 176. 1920.
Typus: Vietnam, Annam, Lang Biang, sur Pin, Eberhardt 196 (lectotype FH 00258973, studied – typified by Ryvarden 1983).
Notes: Fleshy mid-sized polypore with regular, pinkish pores, large, ellipsoid, thick-walled spores, monomitic with very wide and thick-walled, clamped hyphae, partly agglutinated, changing colour upon drying. We do not know the true affinity of this species, and we are not aware of any modern collections. In our opinion it does not belong to any genus in the Cerrenaceae or Spongipellis sensu stricto.
Tyromyces irpiceus Corner, Beih. Nova Hedwigia 96: 143. 1989.
Notes: Corner (1989) described this species from Brazil. According to his description, the species has small pilei and lamellate to irpicoid hymenophore, and Corner compares it with Irpiciporus and Spongipellis sensu lato. According to the protologue, the species is acystidiate and monomitic with thick-walled clamped hyphae. Corner describes the ellipsoid, mid-sized spores as thin-walled. We have not seen the type, but this species should be kept in mind when dealing with Neotropical
Irpiciporus and Somion. Hattori (2002) did not mention this species in his type studies.
Tyromyces sublamellatus Corner, Beih. Nova Hedwigia 96: 199. 1989.
Notes: Corner (1989) likens this Malaysian species to T. irpiceus, which in turn he considers similar to Irpiciporus. Judging from Corner’s description, this might be a species of Irpiciporus. However, Hattori (2003) reports the species as dimitic and having gloeocystidia, relating it to Abortiporus roseus. Clearly this species does not belong to Irpiciporus.
Specimens studied
Acanthodontia cirrhatina. Malaysia, Sabah (see holotype). Indonesia, Sumatera Barat, Sijunjung, Bukit Tujuh, alt. 550 m, dicot, 23 Jul. 2009, Miettinen 13717* (ANDA, H).
Cerrena albocinnamomea. China, Jilin, Antu, Changbai Mts, on Tilia, 3 Sep. 1993, Dai 997 (H, paratype); Acer, 5 Sep. 1993, Dai 1085 (H, paratype); Acer mono, 15 Sep. 1998, Niemelä 6372 (H); dicot, 26 Aug. 2005, Miettinen 10511* (H).
Cerrena ‘gilbertsonii’. Guadeloupe, Basse-Terre, Grande Anse, dicot, unknown collection date, D. Vlasák* (JV 1609/29, H). Mexico (see type).
Cerrena multipileata. Brazil, Parana, Mandirituba, alt. 850 m, 20 Apr. 1993, de Meijer 2623 (O, H); Santa Catarina (see type). Costa Rica, San José, Cerro Vueltas, alt. 2 000 m, 18 Jul. 2001, Ryvarden 43881 (O, H*); Puntarenas, Santa Elena, dicot, 28 & 29 Jul. 2014, Vlasák* (JV 1407/63, H). Guatemala, Huehuetenango, San Mateo Ixtatán, alt. nearly 3 000 m, 21 Nov. 2006, Kout A36* (JV 0611/A36).
Cerrena unicolor. China, Hu (lectotype of Polystictus prosector BPI 0315073, LC23787, selected by Stevenson & Cash 1936: 137). Finland, Etelä-Häme, Lammi, Pappilankylä, Betula, 10 Sep. 1997, Niemelä 6098 (H); Pohjois-Karjala, Tohmajärvi, Rouanaho, Betula, 30 Jun. 1970, Niemelä (H); Kainuu, Hyrynsalmi, Latvakorvensuo, Betula pubescens, 26 Sep. 2010, Miettinen 14197 (H); Suomussalmi, Soidinkangas, B. pubescens, 30 Sep. 2004, Miettinen 9443* (H); Kittilän Lappi, Kittilä, Pallas-Ounas National Park, B. pubescens, 21 Aug. 1990, Niemelä 5352 (H). Kyrgystan, Jalal-Abad, Aksy, Arkyt village, Craetagus, 31 Jul. 2007; Uotila 47588* (H 7200336). USA, Minnesota, Waseca, Janesville, Willis Lake, dicot, 21 Aug. 2013, Miettinen 16729 (H 7005991); New York, Essex Co., Huntington wildlife forest, Arbutus lake, dicot, 17 Sep. 2013, Miettinen 16901 (H).
Cerrena zonata. Australia, Trowutta Arch, 17 Apr. 2008, Gates* (H). China, Yunnan, Kunming Bot. Garden, 30 Jul. 2005, Miettinen 9773* (H); Chuxiong, Zixishan, dicot, 2 Aug. 2005, Miettinen 9889.1* (H). Indonesia, Sumatera Barat, Lima Puluh Kota, Gunung Sago, dicot, 25 Jul. 2009, Miettinen 13798* (ANDA, H). Japan, Tokyo, Quercus, Oct. 1908, Kusano & Nohara (type of Irpiciporus japonicus Murrill NY 00985353). Nepal (see type).
Crustomyces conspicuus. Czech Republic (see type).
Crustomyces subabruptus. Russia, Leningrad reg, Tikhvin, Gorodokskoe, Populus tremula, 28 Jul. 2012, Spirin 4826* (H).
Irpiciporus branchiformis. Tanzania, Tanga, Lushoto, Mazumbai Forest Res., dense forest, on dead wood, 15 Dec. 1995, Niemelä 5937 (H)*; see also type.
Irpiciporus mollis. USA, Florida, Escambia Co., Pensacola, Quercus sp., 25 Nov. 1914, Bartholomew (Fungi Columbiani #4545, H); Manatee Co., Braden river trail, dicot, 8 May 2016, Dollinger 770* (JV, H), Bradenton, dicot, 10 Oct. 2016, Dollinger 962 (JV); Massachusetts, Worcester Co., Worcester, Acer saccharum, 20 Oct. 2013, Miettinen 17338 (H); New Hampshire, Carroll Co., Chocorua, Acer sp., Aug. 1908, Farlow 334 (H ex FH); New Jersey (?), Quercus sp., Sep. 1879, Ellis (North American Fungi #320, H); Pennsylvania, Philadelphia, Wissahickon Creek, Fagus virginiana, Aug. 2008, Vlasák (JV 0808/45, H); Bucks Co., Ralph Stover State Park, Quercus sp., Aug. 2001, Vlasák (JV 0108/115, H); South Carolina, Santee River, Ravenel (herb. Curtis 1729 in K – lectotype); Virginia, Prince William Co., Woodbridge, Liriodendron tulipifera, Sep. 2007, Vlasák* (JV 0709/174, H).
Irpiciporus pachyodon. Bulgaria, Burgas, Strandzha Nat. Park, Quercus sp., 25 Oct. 2007, Heilmann-Clausen 07–286* (H). Czech Republic, Jihočeský kraj, Hluboká nad Vltavou, Quercus petraea, Nov. 1993, Vlasák* (JV 9311/1, H); Středočeský kraj, Průhonický park, Quercus rubra, 1 Nov. 2016, Kotlaba* (JV 1611/1); Vysočina, Velký Špičák, Fagus sylvatica, 2 Oct. 2004, Vampola 199 (H ex MJ). France, Var, Forêt de Janas, Q. suber, 20 Dec. 1987, David (H, O ex LY). Italy, Piedmont, Alessandria, Bosio, Capanne di Marcarolo Nat. Regional Park, Quercus sp., 16 Oct. 2019, Spirin 13785 (H). Portugal, Estremadura, Setúbal, Alto da Guerra, Q. suber, 8 Apr. 1978, Melo 327 (H ex LISU).
Lividopora armeniaca. Malaysia (see type).
Lividopora benetosta. China, Hunan, Sangzhi, Badagongshan NR, 23 Sep. 2000, Härkönen K778* (H); Wulingyuan World Heritage Site, 15 Sep. 1999, Härkönen K8* (H); Yunnan, Xishuangbanna, Botanical Garden, dicot, 5 Aug. 2005, Miettinen 9978.2 (H); 6 Aug. 2005, Miettinen 10020 (H); Biosphere Reserve, Menglun, Moraceae?, 9 Aug. 2005, Miettinen 10142.1 (H); Jinghong, Mandian village, 15 Aug. 2005, Miettinen 10333 (H); Mandian Water Fall surroundings near Jinghong, 17 Aug. 2005, Miettinen 10394.1, 10396.2 (H); Primeval Forest Park near Jinghong, 13 Aug. 2005, Miettinen 10225* (H). French Polynesia (see type). Indonesia, Nusa Tenggara Barat, Lombok Utara, Bentek, dicot, 29 Dec. 2011, Miettinen 15238 (BO, H), 15243 (BO, H); Theobroma cacao, 29 Dec. 2011, Miettinen 15252 (BO, H); Papua, Jayapura Reg, Cyclop Mountains, Fabaceae (?), 22 Aug. 2004, Miettinen 9127.1 (H); dicot, 29 Aug. 2004, Miettinen 9176.2* (H); Sapindaceae/Meliaceae (?), 29 Aug. 2004, Miettinen 9166.5* (H); dicot, 29 Aug. 2004, Miettinen 9188.1 (H); 14 Dec. 2007, Miettinen 12080.1 (MAN, H); Papua Barat, Manokwari Reg, Amberbaken, River Anjii/Wepai near Saukorem, dicot, 1 Nov. 2010, Miettinen 14287 (H); Riau, Indragiri Hulu, Bukit Aluran Babi, dicot, 2 Jul. 2004, Miettinen 8823.2* (H); Pelalwan, Teluk Meranti, dicot, 25 Jul. 2004, Miettinen 9026.2 (BO, H); Sumatera Barat, Pesisir Selatan, Muara Sako, dicot, 22 Apr. 2002, Miettinen 6026 (BO, H); Padang, Limau Manis, 13 Jul. 2008, Miettinen 13011.3 (ANDA, H); Ulu Gadut, dicot, 28 Jul. 2009, Miettinen 13884.1, 13891 (ANDA, H); Sijunjung, Bukit Sebelah, 22 Jul. 2008, Miettinen 13674.1 (ANDA, H). Malaysia, Sabah, Ranau, Poring, dicot, 19 Jun. 2013, Miettinen 16397.2 (SNP 33655, H), Miettinen 16416 (SNP 33667, H). New Zealand, Rotorua, between lakes Rotoiti-Rotoehu, Hongi’s track, 14 Apr. 2004, Hallenberg 15301* (O). Philippines, Zamboanga, San Ramon, 12 May 1904, Copeland 743 (type of Poria porphyrophaea NY 00742723). Puerto Rico, Luquillo, El Yunque National Forest, Bisley, Dacryodes excelca (?), 7 Jan. 2014, Miettinen 18019 (H); Sabana, Cecropia, 8 Jan. 2014, Miettinen 18035* (H); 12 Jan. 2014, Miettinen 18133 (H); 14 Jan. 2014, Miettinen 18140 (H); Yokahú tower, 14 Jan. 2014, Miettinen 18135* (H). Samoa, unknown collection date, Lloyd 5042 (lectotype of Poria fumosa BPI US0318515, isotype FH 290621). Sri Lanka, Gangaruwa, Dec. 1913, Petch 3930 (lectotype of Poria hypobrunnea K(M) 56199). US Virgin Islands, St John, Virgin Islands NP, 8 Feb. 2012, Justo 513* (H). Vietnam, Thanh Hóa, 20 Apr. 1892, Bon 5294 (lectotype of Poria fulvobadia FH 290623).
Lividopora facilis. Indonesia, Riau (see type).
Lividopora subvincta. Kenya, Taita-Taveta, Taita Hills, Ngangao, dicot, 24 Nov. 2017, Savchenko 171124/1505 (H 7008794); dicot, 29 Nov. 2017, Savchenko 171129/1309A* (H 7008878). Zimbabwe (see type).
Pseudolagarobasidium belizense. Brazil, Pará, Vicinal Das Paranarense, Municipio de Aveiro, Hevea brasiliensis, unknown collection date, Gazis VPB197* (H). Costa Rica, Guanacaste, Reserva Biologica Lomas Barbudal, angiosperm, 14 Jul. 2001, KH Larsson 11363* (O, H).
Lividopora vincta. Brazil, Amazon, Rio Uaupés, Ipanoré (“Panuré”), on dead trees, Feb. 1853, Spruce 178 (lectotype of Polyporus carneopallens K(M) 192248, isotype FH 00290615). Costa Rica, San José, Ciudad Colon, alt. 800 m, 23 Jul. 1963, Lowe L-13218-Sp (CFMR). Puntarenas, Tarcoles, Villa LaPaz, dicot, 22 Apr. 2017, Vlasák* (JV 1704/102). Dominican Republic (K, type). USA, Florida, Alachua Co., Gainesville, dicot, 24 Nov. 2013, Miettinen 17916.1* (H).
Pseudolagarobasidium calcareum. Taiwan, Nantou, Sun-Moon Lake, Castanopsis kusanoi, 26 Oct. 1988, Wu 881026–18 (H 7003571).
Pseudolagarobasidium subvinosum. Taiwan, Hualien, Hsiulin Hsiang, Leucaena leucocephala, Sep. 1986, Wu 8609 (H 7003570).
Pseudolagarobasidium venustum. Brazil, São Paulo, Cananeia, Ilha do Cardoso, dicot, 2–5 Feb. 1987, Ryvarden 24717 (GB, paratype), see also holotype. Colombia, Magdalena, Parque Nacional Tayrona, Estacion Canaveral, 17–19 Jun. 1978, Ryvarden 15910B (GB, paratype). Costa Rica, unknown collection date, Carranza 120929* (O); Guanacaste, Tempisque, Reserva Biologica Lomas Barbudal, on decaying dicot wood, 14 Jul. 2001, K.H. Larsson 11363* (GB). Puerto Rico, Luquillo, Sabana, Bisley, dicot, 6 Jun. 1997, K.H. Larsson 10040* (GB).
Radulodon americanus. Canada (see type).
Radulodon casearius. USA, Fungi Caroliniani Exsiccati by H.W. Ravenel, fasc. III, 20. “Hydnum trichodontium”, Quercus sp. (H).
Radulodon erikssonii. Finland, Pohjois-Häme, Vesijaon luonnonpuisto, 21 Sep. 2018, Pennanen 3886* (H); Pohjois- Savo, Savonlinna, Haukiniemi, Populus tremula, 9 Nov. 2018, Pennanen 3794* (H); Pieksänmaa, Kivimäki, P. tremula, 29 Sep. 2006, Miettinen 10977 (H). Norway (see type). Switzerland, Ticino, Losone, Maia, P. tremula, 30 Apr. 1988, Martini* (GB 0181279).
Somion delectans. USA, Maine. York Co., Kittery Point, Carya ovata, Oct. 1922, Thaxter 799 (H ex FH); New Jersey, Carroll Co., North Conway, Betula sp., Sep. 2008, Vlasák 0809/62* (JV); Ohio, Cincinnati, fallen log, unknown collection date, Morgan 106 (BPI – isotype); Pennsylvania, Montgomery Co., Green Lane State Park, Carya sp., Jul. 2015, J. Vlasák Jr.* (JV 1507/22, H); Chester Co., Phoenixville, Acer rubrum, Nov. 2018, J. Vlasák Jr.* (JV 1811/9).
Somion litschaueri. Czech Republic, Jihomoravský kraj, Valtice, Quercus cerris, 10 Sep. 1998, Vampola 198 (H ex MJ); 3 Sep. 2013, Vlasák* (JV 1309/1, H). Slovakia, Zvolen, Čertova Skala Nat. Res., Quercus sp., 4 Sep. 2013, Vlasák* (JV 1309/7, H).
Somion occarium. Czech Republic, Jihočeský kraj, Jindřichův Hradec, Suchdol nad Lužnicí, Fagus sylvatica, Oct. 2013, Hlásek* (JV 1310/23, H); Jihomoravský kraj (see epitype); Vysočina, Doupě, F. sylvatica, 17 Nov. 1994, Vampola (H ex MJ, Polyporales Exsiccati Čechoslaviacae 149). Sweden, Skåne, Kullaberg, Brunnby, F. sylvatica, 20 Nov. 2009, KH Larsson 14261* (GB). Tunisia, El Fedja, Quercus suber, Jan. 1893, herb. Patouillard (lectotype of Spongipellis suberis FH). Ukraine, Zakarpatska Reg., Dilove, Mt. Menchul, F. sylvatica, Aug. 1934, Pilát (holotype of Leptoporus bredecelensis PRM 623854).
Somion strenuum. China, Liaoning, Anshan, Qian Mts. Park, Quercus sp., 22 Aug. 2005, Miettinen 10456* (H). Russia, Khabarovsk Reg., Komsomolsk Dist., Boktor, Quercus mongolica, 18 Aug. 2013, Spirin 6112* (H); Solnechnyi Dist., Igdomi, Q. mongolica, 6 Sep. 2016, Spirin 10989 (H); Sonakh (see type); Ulchskii Dist., Susanino, Q. mongolica, 27–29 Aug. 1976, Alanko 31049, 31153 (H).
Somion tomsovskyi. Mexico, San Luis Potosí, Ciudad de Maiz, 23 May 1963, Lemke (H ex O). USA, Arizona, Cochise Co., Chiricahua, Quercus hypoleucoides, 6 Oct. 1967, Gilbertson 7638 (H ex O); 5 Sep. 2012, J. Vlasák Jr.* (JV 1209/55, H); Quercus sp., 19 Jul. 2013, J. Vlasák Jr.* (JV 1307/8, H); Pima Co., Madera Canyon, Quercus sp., 20 Nov. 2016, J. Vlasák Jr.* (JV 1611/1).
Somion unicolor. Canada, Ontario, Renfrew Co., Petawawa Forest Station, Quercus borealis, Aug. 1937, Lewis (H ex DAOM 9080). USA, Missouri, Perry Co., Perryville, dead logs, 1884, Demetrio (Rabenhorst-Winter’s Fungi Europaei #3330, H); New Jersey, Atlantic Co., Hammonton, Wharton State Forest, Quercus sp., 15 Apr. 2013, J. Vlasák Jr. 1304/1* (JV, H); Burlington Co., Batsto Village, Quercus sp., Aug. 2017, J. Vlasák Jr. 1708/10* (JV, H); Acer rubrum, Jan. 2021, J. Vlasák Jr. 2102/2* (JV).
Trametes meyenii. Indonesia, Nusa Tenggara Barat, Lombok Utara, Bentek, dicot, 29 Dec. 2011, Miettinen 15249 (BO, H); Papua Barat, Teluk Wondama, Werianggi-Werabur, 7 Sep. 2004, Miettinen 9274 (BO, H).
Trametes sclerodepsis. Ecuador, Orellana, Yasuni NP, 12 Mar. 2002, Ryvarden 44671A (O, H).
DISCUSSION
We have inferred a phylogeny of the family Cerrenaceae with a 6-marker dataset to revise its classification at the genus level. Balancing morphological data and phylogenetic information, we have adopted a scheme of seven genera. Other schemes would also be feasible for the family: three large genera (Cerrena, Irpiciporus, and Somion), six genera (as in the seven-genus solution but Lividopora included in Cerrena) or nine small genera (as in the seven-genus solution, but Cerrena and Somion divided into two each). The latter are fairly similar phylogenetically to the seven-genus solution, but genera in them would be more difficult to define morphologically. The phylogenetically simplest three-genus solution is worthy of further comments.
Nomenclaturally, the three-genus option would cause many more changes to the status quo than the other options. On the positive side, the three genera would be phylogenetically more distinct (distant) than in the other solutions, and therefore likely more robust over time, when more species are discovered and added to the phylogenetic estimate. In the other schemes, compulsory modifications are more likely, when species that do not fit to genera, for instance within the Cerrena-Pseudolagarobasidium clade, turn up. However, we cannot work with the unknown, and the above-mentioned point of view should not be overemphasized. Our sampling covers all forested continents and is tolerably representative of genus diversity in the family.
If we were to define genera for the hydnoid members of the family in isolation, then division into Irpiciporus (incl. Radulodon) and Pseudolagarobasidium would be well justified both morphologically and phylogenetically. However, once polypores are added, either Pseudolagarobasidium would need to be included in a morphologically heterogeneous Cerrena (the three-genus solution), or the Irpiciporus clade would need to be divided into three genera (the seven-genus solution we have adopted, Fig. 3). Either way, the solution no longer appears optimal from the isolationist perspective.
Defining genera from the polypore perspective, division into four (Irpiciporus, Somion, Cerrena, and Lividopora) is the most natural solution morphologically, and the one we have adopted here, even if it causes splitting of hydnoid taxa. The three-genus solution (Cerrena incl. Lividopora, Irpiciporus, and Somion) could be morphologically somehow justified. Again, when hydnoid taxa are added, the Irpiciporus concept becomes more diluted and Cerrena sensu lato would include nearly monomitic, hydnoid species of Pseudolagarobasidium, making it a yet more difficult concept morphologically.
We have chosen here the seven-genus solution as the one optimizing morphological recognition with phylogenetic signal, while minimizing nomenclatural changes. In doing so we have had to abandon easy-to-define genera for hydnoid fungi. This underlies the importance of integrating different morphogroups and their research traditions when making conclusions on higher- level taxonomy. Polypores and corticioid fungi in particular are very often intermixed above the genus level, as is the case of the Cerrenaceae, Irpicaceae, Polyporaceae, and Steccherinaceae to give a few examples from the Polyporales. Our seven-genus solution avoids placing strictly hydnoid and poroid species in the same genus, which would have been the case for the three-genus solution.
Can the family Cerrenaceae be defined morphologically? Definition in the strict sense is not feasible, as is the case for most families in the Polyporales. A few general characters are shared by all the known species: mid-sized spores that are slightly cyanophilous if they are thick-walled, mid-sized to large basidia, hyphal structure that is never agglutinated, aggressive white rot; many, if not all species, are tree parasites or pathogens. These characters are found in many other families in Agaricomycetes and even as a combination are not unique to the Cerrenaceae.
We have focused on morphological and phylogenetic characters of the Cerrenaceae. Ecologically this family contains only species that inhabit trees, though quite many species are able to colonize living trees already and some are considered tree diseases. Some wood decay fungi are able to grow in soil as well, but this does not seem to be the case with the Cerrenaceae. When compiling ITS sequences for this study, we searched the UNITE database for species that belong to this family. UNITE contains many unique sequences, mostly soil-derived, not available through GenBank, but only few additional sequences were found through UNITE in this case, indicating that they are not an important component of soil funga.
Representatives of all the genera in the Cerrenaceae have been studied for their cultural morphology in varying degree with the exception of Acanthodontia, which has not been cultivated to our knowledge. In particular, Cerrena unicolor has been studied for its enzymes associated with white rot (see Introduction). When grown on agar plates, members of the family produce fast-growing, white, well-spaced mycelium cottony on the surface, with clamps in part of the septa, conidia, and they show signs of laccase and peroxidase activity (David 1969, Setliff 1972a, Stalpers 1978, Woods & Ginns 2006). In this sense the Cerrenaceae are rather uniform, but with the current sampling of a single specimen and species per genus, little can be said on how the genera differ in their cultural characters, if at all. The above-mentioned set of characters is also not unique to the Cerrenaceae, and for instance in the key of Stalpers (1978), the family appears in different parts of the key intermixed with unrelated species. It would appear that cultural characters are not very useful for the systematics of the Cerrenaceae.
Surprisingly, only one high-quality genome sequence, Cerrena unicolor, has been produced for the whole family, by the US Joint Genome Institute. Even this genome is not yet public, though it is visible in the Mycocosm database (Grigoryev et al. 2013). It is a typical white-rot polypore genome in size and in its gene count of carbohydrate active enzymes such as class II peroxidases and other genes associated with wood decomposition. Considering how easy the Cerrenaceae are to culture and due to their economic importance as tree pathogens, we would expect more high-quality genome sequences to be published soon, enabling comparative genomics.
We will end this paper with a note on the intriguing ecology of the Cerrenaceae. Cerrena unicolor is spread by several species of the woodwasp (Siricidae) genera Tremex and Eriotremex (Stillwell 1964, Tabata & Abe 1995, Pažoutová & Šrůtka 2007, Schiff et al. 2012). The symbiosis between woodwasp and Amylostereum (Russulales) is well-documented, but so far, no other fungi than Amylostereum and Cerrena are known to be associated with woodwasps. Could other species of Cerrena be associated with insects in a similar manner? And to expand, many species in this family attack living trees as mentioned in the introduction. In addition to Cerrena, also Pseudolagarobasidium and Somion are pathogenic; Lividopora spp. are known to be tree pathogens but also endophytes, i.e. present as mycelium in healthy plant tissues. Could insect association provide a route for these species to enter living trees?
Acknowledgments
We would like to thank Genevieve Gates, Romina Gazis, Jacob Heilmann-Clausen and Alfredo Justo for generously sharing their material, Yu-Cheng Dai and his research group for joint field work, University of Andalas for arrangements of field trips in Sumatra, Matthew Smith for hosting OM in Florida, Jean Lodge and the US forest service for making field work in Puerto Rico possible, and Alfredo Justo for sequences. Rolinus Paulous assisted during the field work in Malaysia. We are indebted to Alexander Sennikov and Konstanze Bensch for their advice on nomenclatural questions. Gaurav Sablok assembled genomes that provided some sequences for this study. Andy Overall provided us a photo of Somion occarium, as did Tuomo Niemelä for C. albocinnamomea. We acknowledge Abbot Oghenekaro for help in sequencing and IT Center for Science, Finland, for computational resources. Funding for this project was provided by the European Research Council (Marie Curie International Outgoing Fellowship), National Science Foundation project PolyPEET, institutional support of the Academy Sciences of the Czech Republic RVO: 60077344, Academy of Finland project grant 315927, University of Helsinki 3-year research grant, and White Rose mechanistic biology DTP. Finnish Barcode of Life (FinBOL) ITS data were utilized here. Malaysian collections were made under Sabah Biodiversity Council permit JKM/MBS.1000-2/2 JLD.11(3).
Conflict of interest
The authors declare that there is no conflict of interest.
Supplementary material
Supplementary Material: http://fuse-journal.org/
Bayesian consensus tree of Cerrenaceae based on nrDNA ITS and LSU sequences. Countries (and states) are denoted with ISO 3166 codes.
Bayesian consensus tree of the Cerrenaceae based on mitochondrial SSU sequences.
Bayesian consensus tree of the Cerrenaceae based on mitochondrial ATP6 sequences.
Bayesian consensus tree of the Cerrenaceae based on nuclear RPB1 sequences.
Bayesian consensus tree of the Cerrenaceae based on nuclear TEF1 sequences.
REFERENCES
- Abarenkov K, Tedersoo L, Nilsson RH.et al. (2010). PlutoF – a web based workbench for ecological and taxonomic research, with an online implementation for fungal ITS sequences. Evolutionary Bioinformatics 6: EBO.S6271. [Google Scholar]
- Adanson M.(1763). Familles des plantes. Vincent, Paris. [Google Scholar]
- Altschul SF, Madden TL, Schäffer AA.et al. (1997). Gapped BLAST and PSI-BLAST: a new generation of protein database search programs. Nucleic Acids Research 25: 3389–3402. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Batsch AJGK.(1783). Elenchus fungorum. Halle. [Google Scholar]
- Berkeley MJ.(1854). Decades of fungi. Decades XLIV–XLVI. Indian fungi. Hooker’s Journal of Botany and Kew Garden Miscellany 6: 161–174. [Google Scholar]
- Bernicchia A.(2005). Polyporaceae s.l., vol 10. Fungi Europaei. Candusso, Alassio. [Google Scholar]
- Bondartsev AS.(1953). Trutovye griby evropeiskoi chasti SSSR i Kavkaza. Academy of the Sciences of the USSR, Moscow-Leningrad. [Google Scholar]
- Bulliard P.(1789). Herbier de la France, vol 9. Bulliard, Paris. [Google Scholar]
- Černý A.(1979). BBělochoroš bukový - Sponipellis delectans (Peck) Murr. - nový choroš pro ČSSR. Česká Mykologie 33: 99–105. [Google Scholar]
- Chen C-C, Chen C-Y, Wu S-H.(2021). Species diversity, taxonomy and multi-gene phylogeny of phlebioid clade (Phanerochaetaceae, Irpicaceae, Meruliaceae) of Polyporales. Fungal Diversity 111: 337–442. [Google Scholar]
- Corner EJH.(1987). Ad Polyporaceas IV. Beihefte zur Nova Hedwigia 86: 1–276. [Google Scholar]
- Corner EJH.(1989). Ad Polyporaceas V. Beihefte zur Nova Hedwigia 96: 1–218. [Google Scholar]
- Dai Y-C, Cui B-K, Yuan H-S.et al. (2007). Pathogenic wood-decaying fungi in China. Forest Pathology 37: 105–120. [Google Scholar]
- Dai Y-C, Niemelä T.(1997). Changbai wood-rotting fungi 6. study on Antrodiella, two new species and notes on some other species. Mycotaxon 64: 67–81. [Google Scholar]
- Darriba D, Posada D, Kozlov AM.et al. (2020). ModelTest-NG: A new and scalable tool for the selection of DNA and protein evolutionary models. Molecular Biology and Evolution 37: 291–294. [DOI] [PMC free article] [PubMed] [Google Scholar]
- David A.(1969). Caractères culturaux et cytologiques d’espèces du genre Spongipellis Pat. et affines. Bulletin Mensuel de la Société Linnéenne de Lyon 38: 191–201. [Google Scholar]
- Donk MA.(1960). The generic names proposed for Polyporaceae. Persoonia 1: 173–302. [Google Scholar]
- Donk MA.(1974). Check-list of European polypores. North-Holland Pub. Comp., Amsterdam. [Google Scholar]
- Dvořák D, Běťák J, Tomšovský M.(2014). Aurantiporus alborubescens (Basidiomycota, Polyporales) – first record in the Carpathians and notes on its systematic position. Czech Mycology 66: 71–84. [Google Scholar]
- Elisashvili V, Kachlishvili E, Khardziani T.et al. (2010). Effect of aromatic compounds on the production of laccase and manganese peroxidase by white-rot basidiomycetes. Journal of Industrial Microbiology & Biotechnology 37: 1091–1096. [DOI] [PubMed] [Google Scholar]
- Eriksson J, Hjortstam K, Ryvarden L.(1981). The Corticiaceae of North Europe 6. Phlebia-Sarcodontia. Fungiflora, Oslo. [Google Scholar]
- Fries EM.(1821). Systema mycologicum 1. Ex officina Berlingiana, Lund. [Google Scholar]
- Fries EM.(1828). Elenchus fungorum. Sumptibus E. Mauritii. [Google Scholar]
- Fries EM.(1836–1838). Epicrisis systematis mycologici. Typographia Academica, Uppsala. [Google Scholar]
- Garbelotto MM, Lee HK, Slaughter G.et al. (1997). Heterokaryosis is not required for virulence of Heterobasidion annosum. Mycologia 89: 92–102. [Google Scholar]
- Gilbertson RL, Ryvarden L.(1986). North American Polypores Vol. 1. Abortiporus to Lindtneria. Fungiflora, Oslo. [Google Scholar]
- Gilbertson RL, Ryvarden L.(1987). North American Polypores Vol. 2. Megasporoporia to Wrightoporia. Fungiflora, Oslo. [Google Scholar]
- Gray SF.(1821). Natural arrangement of British plants, vol 1. Baldwin, Cradock and Joy, London. [Google Scholar]
- Grigoriev IV, Nikitin R, Haridas S.et al. (2013). MycoCosm portal: gearing up for 1000 fungal genomes. Nucleic Acids Research 42: D699–D704. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gutaker RM, Reiter E, Furtwängler A.et al. (2017). Extraction of ultrashort DNA molecules from herbarium specimens. Biotechniques 62: 76–79. [DOI] [PubMed] [Google Scholar]
- Hallenberg N, Ryberg M, Nilsson RH.et al. (2008). Pseudolagarobasidium (Basidiomycota): on the reinstatement of a genus of parasitic, saprophytic, and endophytic resupinate fungi. Botany 86: 1319–1325. [Google Scholar]
- Hartikainen ES, Miettinen O, Hatakka A.et al. (2016). Decolorization of six synthetic dyes by fungi. American Journal of Environmental Sciences 12: 77–85. [Google Scholar]
- Hattori T.(2001). Type studies of the polypores described by E.J.H. Corner from Asia and West Pacific Areas II. Species described in Gloeophyllum, Heteroporus, Microporellus, Oxyporus, Paratrichaptum, and Rigidoporus. Mycoscience 42: 19–28. [Google Scholar]
- Hattori T.(2002). Type studies of the polypores described by E.J.H. Corner from Asia and West Pacific Areas. IV. Species described in Tyromyces (1). Mycoscience 43: 307–315. [Google Scholar]
- Hattori T.(2003). Type studies of the polypores described by E.J.H. Corner from Asia and West Pacific Areas. VI. Species described in Tyromyces (3), Cristelloporia, Grifola, Hapalopilus, Heterobasidion, Ischnoderma, Loweporus, and Stecchericium. Mycoscience 44: 453–463. [Google Scholar]
- Hibbett DS, Binder M, Bischoff JF.et al. (2007). A higher-level phylogenetic classification of the Fungi. Mycological Research 111: 509–547. [DOI] [PubMed] [Google Scholar]
- Hjortstam K.(1987). A check-list of genera and species of corticioid fungi (Hymenomycetes). Windahlia 17: 55–85. [Google Scholar]
- Hjortstam K, Larsson K-H.(1995). Annotated check-list to genera and species of corticioid fungi (Aphyllophorales, Basidiomycotina ) with special regards to tropical and subtropical areas. Windahlia 21: 1–75. [Google Scholar]
- Hood IA, Dick M.(1988). Junghuhnia vincta (Berkeley) comb. nov., root pathogen of Pinus radiata. New Zealand Journal of Botany 26: 113–116. [Google Scholar]
- Hooker JD.(1854). Himalayan journals; or, Notes of a naturalist in Bengal, the Sikkim and Nepal Himalayas, the Khasia Mountains, vol 1. J. Murray, London. [Google Scholar]
- Ipulet P, Ryvarden L.(2005). New and interesting polypores from Uganda. Synopsis Fungorum 20: 87–99. [Google Scholar]
- Jang JC, Chen T.(1985). Pseudolagarobasidium leguminicola gen. et sp. nov. on Leucaena in Taiwan. Transactions of the British Mycological Society 85: 374–377. [Google Scholar]
- Janusz G, Mazur A, Wielbo J.et al. (2018). Comparative transcriptomic analysis of Cerrena unicolor revealed differential expression of genes engaged in degradation of various kinds of wood. Microbiological Research 207: 256–268. [DOI] [PubMed] [Google Scholar]
- Janusz G, Rogalski J, Szczodrak J.(2007). Increased production of laccase by Cerrena unicolor in submerged liquid cultures. World Journal of Microbiology and Biotechnology 23: 1459–1464. [Google Scholar]
- Justo A, Hibbett D.(2011). Phylogenetic classification of Trametes (Basidiomycota, Polyporales) based on a five-marker dataset Taxon 60: 1567–1583. [Google Scholar]
- Justo A, Miettinen O, Floudas D.et al. (2017). A revised family-level classification of the Polyporales (Basidiomycota). Fungal Biology 121: 798–824. [DOI] [PubMed] [Google Scholar]
- Katoh K, Rozewicki J, Yamada KD.(2017). MAFFT online service: multiple sequence alignment, interactive sequence choice and visualization. Briefings in Bioinformatics 20: 1160–1166. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kaur G, Singh AP, Dhingra GS.(2014). Radulodon acaciae sp. nov. from India. Mycotaxon 127: 111–113. [Google Scholar]
- Kotiranta H, Kulju M, Miettinen O.(2017). Caudicicola gracilis (Polyporales, Basidiomycota), a new polypore species and genus from Finland. Annales Botanici Fennici 54: 159–167. [Google Scholar]
- Kotlaba F, Pouzar Z.(1957). Nové nebo málo známé choroše pro Československo. Česká Mykologie 9: 214–224. [Google Scholar]
- Kotlaba F, Pouzar Z.(1965). Spongipellis litschaueri Lohwag a Tyromyces kmetii (Bres.) Bond. et Sing., dva vzácné bělochoroše v Československu (Spongipellis litschaueri Lohwag and Tyromyces kmetii (Bres.) Bond. et Sing., two rare polypores in Czechoslovakia). Česká Mykologie 19: 69–78. [Google Scholar]
- Kozlov AM, Darriba D, Flouri T.et al. (2019). RAxML-NG: a fast, scalable and user-friendly tool for maximum likelihood phylogenetic inference. Bioinformatics 35: 4453–4455. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kretzer AM, Bruns TD.(1999). Use of atp6 in fungal phylogenetics: an example from the Boletales. Molecular Phylogenetics and Evolution 13: 483–492. [DOI] [PubMed] [Google Scholar]
- Kumar S, Stecher G, Tamura K.(2016). MEGA7: Molecular Evolutionary Genetics Analysis Version 7.0 for bigger datasets. Molecular Biology and Evolution 33: 1870–1874. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lee SS, Noraini Sikin Y.(1999). Fungi associated with heart rot of Acacia mangium trees in Peninsular Malaysia and East Kalimantan. Journal of Tropical Forest Science 11: 240. [Google Scholar]
- Li Y, Nakasone KK, Chen C-C.et al. (2022). Taxonomy and phylogeny of Cystostereaceae (Agaricales, Basidiomycota): a new genus, five new species, and three new combinations. Journal of Fungi 8: 1229. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lisova ZA, Lisov AV, Leontievsky AA.(2010). Two laccase isoforms of the basidiomycete Cerrena unicolor VKMF-3196. Induction, isolation and properties. Journal of Basic Microbiology 50: 72–82. [DOI] [PubMed] [Google Scholar]
- Ljubarsky D.(1934). On fungal plant deceases and wood-rotters in the South Ussuri area. Vestnik DVFAN SSSR 9: 75–104. [translated from Russian] [Google Scholar]
- Lowe JL.(1975). Polyporaceae of North America. The genus Tyromyces. Mycotaxon 2: 1–82. [Google Scholar]
- Löytynoja A.(2021). Phylogeny-aware alignment with PRANK and PAGAN. In: Katoh K. (ed) Multiple sequence alignment: methods and protocols. Springer US, New York, NY: 17–37. [DOI] [PubMed] [Google Scholar]
- Maas Geesteranus RA.(1974). Studies in the genera Irpex and Steccherinum. Persoonia 7: 443–581. [Google Scholar]
- Maekawa N.(2002). Pseudolagarobasidium calcareum: Japanese records and cultural characteristics. Mycoscience 43: 271–275. [Google Scholar]
- Maekawa N, Hasebe K.(2002). Pseudolagarobasidium calcareum: Japanese records and cultural characteristics. Mycoscience 43: 271–275. [Google Scholar]
- Maekawa N, Sugawara R, Kogi H.et al. (2023). Hypochnicium sensu lato (Polyporales, Basidiomycota) from Japan, with descriptions of a new genus and three new species. Mycoscience 64: 19–34. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Martin R, Gazis R, Skaltsas D.et al. (2015). Unexpected diversity of basidiomycetous endophytes in sapwood and leaves of Hevea. Mycologia 107: 284–297. [DOI] [PubMed] [Google Scholar]
- Matheny PB, Liu YJ, Ammirati JF.et al. (2002). Using RPB1 sequences to improve phylogenetic inference among mushrooms (Inocybe, Agaricales). American Journal of Botany 89: 688–698. [DOI] [PubMed] [Google Scholar]
- Micheli PA.(1729). Nova plantarum genera. Florence. [Google Scholar]
- Miettinen O, Larsson E, Sjökvist E.et al. (2012). Comprehensive taxon sampling reveals unaccounted diversity and morphological plasticity in a group of dimitic polypores (Polyporales, Basidiomycota). Cladistics 28: 251–270. [DOI] [PubMed] [Google Scholar]
- Miettinen O, Vlasák J, Rivoire B, Spirin V.(2018). Postia caesia complex (Polyporales, Basidiomycota) in temperate Northern Hemisphere. Fungal Systematics and Evolution 1: 101–129. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Murrill WA.(1903). A historical review of the genera of Polyporaceae. Journal of Mycology 9: 87–102. [Google Scholar]
- Murrill WA.(1905). The Polyporaceae of North America: XII. A synopsis of the white and bright-colored pileate species. Bulletin of the Torrey Botanical Club 32: 469–493. [Google Scholar]
- Murrill WA.(1908). Polyporaceae, Part 2. North American Flora 9: 73–173. [Google Scholar]
- Müller J, Müller K, Quandt D.(2010). PhyDE – Phylogenetic Data Editor, version 0.997. http://phyde.de. [Google Scholar]
- Nakasone K, Ortiz-Santana B.(2022). New species and combinations in the Cerrenaceae (Polyporales, Basidiomycota). Lilloa 59 (Suppl.): 89–113. [Google Scholar]
- Nakasone KK.(2001). Taxonomy of the genus Radulodon. Harvard Papers in Botany 6: 163–177. [Google Scholar]
- Nakasone KK.(2012). Type studies of corticioid Hymenomycetes (Basidiomycota) with aculei – Part II. Czech Mycology 64: 23–42. [Google Scholar]
- Nakasone KK.(2015). Taxonomic studies in Chrysoderma, Corneromyces, Dendrophysellum, Hyphoradulum, and Mycobonia. Mycotaxon 130: 369–397. [Google Scholar]
- Nakasone KK, Lindner DL.(2012). Taxonomy of Pseudolagarobasidium (Polyporales, Basidiomycota). Fungal Diversity 55: 155–169. [Google Scholar]
- Nakasone KK, Ortiz-Santana B, He S-H.(2021). Taxonomic studies of crust fungi with spines in Radulomyces, Sarcodontia, and the new genus Noblesia. Mycological Progress 20: 1479–1501. [Google Scholar]
- Niemelä T.(2005). Käävät, puiden sienet. Polypores, lignicolous fungi. Norrlinia 13: 1-320 [Google Scholar]
- Nikolaeva TL.(1964). Новый и впервые обнарушенные в СССР Виды ежовиковых грибов (сем. Hydnaceae) (Novyy i vpervye obnarushennye v SSSR vidy ezhovikovyh gribov (sem. Hydnaceae)). Novosti Sistematiki Nizshikh Rastenii 1: 168–175. [Google Scholar]
- Nilsson RH, Glöckner FO, Saar I.et al. (2018). The UNITE database for molecular identification of fungi: handling dark taxa and parallel taxonomic classifications. Nucleic Acids Research 47: D259–D264. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nobles MK.(1948). Studies in forest pathology VI. Identification of cultures of wood-rotting fungi. Canadian Journal of Research C 26: 281–431. [DOI] [PubMed] [Google Scholar]
- Nobles MK.(1965). Identification of cultures of wood-inhabiting Hymenomycetes. Canadian Journal of Botany 43: 1097-1139. [Google Scholar]
- Nuñez M, Ryvarden L.(2001). East Asian polypores, volume 2 - Polyporaceae s. lato. Synopsis Fungorum 14: 169–522. [Google Scholar]
- Pažoutová S, Šrůtka P.(2007). Symbiotic relationship between Cerrena unicolor and the horntail Tremex fuscicornis recorded in the Czech Republic. Czech Mycology 59: 83–90. [Google Scholar]
- Persoon CH.(1801). Synopsis methodica fungorum. Göttingen. [Google Scholar]
- Rajchenberg M.(1994). A taxonomic study of the subantarctic Piptoporus (Polyporaceae, Basidiomycetes) I. Nordic Journal of Botany 14: 435–449. [Google Scholar]
- Rehner SA, Buckley E.(2005). A Beauveria phylogeny inferred from nuclear ITS and EF1-α sequences: evidence for cryptic diversification and links to Cordyceps teleomorphs. Mycologia 97: 84–98. [DOI] [PubMed] [Google Scholar]
- Rivoire B.(2020). Polypores de France et d’Europe. Mycopolydev, Orliénas. [Google Scholar]
- Ronquist F, Teslenko M, van der Mark P.et al. (2012). MrBayes 3.2: efficient Bayesian phylogenetic inference and model choice across a large model space. Systematic Biology 61: 539–542. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ryvarden L.(1972a). Radulodon, a new genus in the Corticiaceae (Basidiomycetes). Canadian Journal of Botany 50: 2073–2076. [Google Scholar]
- Ryvarden L.(1972b). Studies on the Aphyllophorales of the Canary Islands with a note on the genus Perenniporia Murr. Norwegian Journal of Botany 19: 139–144. [Google Scholar]
- Ryvarden L.(1977). Type studies in the Polyporaceae 10. Species described by J. M. Berkeley, either alone or with other authors, from 1844 to 1845. Norwegian Journal of Botany 24: 213–230. [Google Scholar]
- Ryvarden L.(1983). Type studies in the Polyporaceae 14. species described by N. Patouillard, either alone or with other mycologists. Occasional papers of the Farlow Herbarium of Cryptogamic Botany. Harvard University Herbaria, Cambridge, MA. [Google Scholar]
- Ryvarden L.(1984). Type studies in the Polyporaceae 16. Species described by J. M. Berkeley, either alone or with other mycologists from 1856 to 1886. Mycotaxon 20: 329–363. [Google Scholar]
- Ryvarden L.(1988). Type studies in the Polyporaceae. 20. Species described by G. Bresadola. Mycotaxon 33: 303–327. [Google Scholar]
- Ryvarden L.(1991). Genera of polypores. Nomenclature and taxonomy. Synopsis Fungorum 5: 1–363. [Google Scholar]
- Ryvarden L.(1992). On Irpex zonatus. Boletin de la Sociedad Argentina de Botánica 28: 227–231. [Google Scholar]
- Ryvarden L.(2012). Studies in neotropical polypores 33. Cerrena gilbertsonii nov. sp. Synopsis Fungorum 30: 44–45. [Google Scholar]
- Ryvarden L.(2015). Neotropical polypores, part 2. Polyporaceae, Abortiporus-Nigroporus. Synopsis Fungorum 34: 232–443. [Google Scholar]
- Ryvarden L.(2018). Studies in African Aphyllophorales 25. New species from East and Central Africa. Synopsis Fungorum 38: 25–32. [Google Scholar]
- Ryvarden L.(2020a). Aphyllophorales 36 - more new African polypores. Synopsis Fungorum 40: 101–105. [Google Scholar]
- Ryvarden L.(2020b). The genus Irpex - a synopsis. Synopsis Fungorum 41: 33–49. [Google Scholar]
- Ryvarden L, Johansen I.(1980). A preliminary polypore flora of East Africa. Fungiflora, Oslo. [Google Scholar]
- Ryvarden L, Melo I.(2016). Poroid fungi of Europe. vol 37, 2nd revised edition edn. Fungiflora, Oslo. [Google Scholar]
- Savchenko A, Zamora JC, Shirouzu T.et al. (2021). Revisionof Cerinomyces (Dacrymycetes, Basidiomycota) with notes on morphologically and historically related taxa. Studies in Mycology 99: 1–72. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sayers EW, Bolton EE, Brister JR.et al. (2022). Database resources of the National Center for Biotechnology Information in 2023. Nucleic Acids Research 51: D29–D38. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schiff NM, Goulet H, Smith DR.et al. (2012). Siricidae (Hymenoptera: Symphyta: Siricoidea) of the Western Hemisphere. Canadian Journal of Arthropod Identification 21: 1–305. [Google Scholar]
- Schweinitz LD.(1822). Synopsis fungorum Carolinae Superioris. Schriften der Naturforschenden Gesellschaft zu Leipzig 1: 21–122. [Google Scholar]
- Setliff EC.(1972a). Cultural characteristics of Poria vincta. Mycologia 64: 641–646. [Google Scholar]
- Setliff EC.(1972b). The taxonomy and morphology of Poria vincta. Mycologia 64: 689–701. [Google Scholar]
- Setliff EC, Mesner W.(1971). A root rot disease of forest trees caused by Poria vincta var. cinerea. Plant Disease Reporter 55: 257–260. [Google Scholar]
- Spirin V, Vlasák J, Niemelä T, et al. (2013). What is Antrodia sensu stricto? Mycologia 105: 1555–1576. [DOI] [PubMed] [Google Scholar]
- Spirin V, Vlasák J, Niemelä T, Miettin O.(2022). Studies in Spongipellis sensu stricto (Polyporales, Basidiomycota). Lilloa 59 (Suppl.): 341–358. [Google Scholar]
- Stevenson JA, Cash EK.(1936). The new fungus names proposed by C. G. Lloyd. Bulletin of the Lloyd library and museum 35: 1–209. [Google Scholar]
- Stillwell MA.(1964). The fungus associated with woodwasps occurring in beech in New Brunswick. Canadian Journal of Botany 42: 495–496. [Google Scholar]
- Tabata M, Abe Y.(1995). Cerrena unicolor isolated from the mycangia of a horntail, Tremex longicollis, in Kochi Prefecture, Japan. Mycoscience 36: 447–450. [Google Scholar]
- Thiers B.(2023). Index Herbariorum. http://sweetgum.nybg.org/science/ih. Accessed 24 Apr. 2023. [Google Scholar]
- Tomšovský M.(2012). Delimitati of an almost forgotten species Spongipellis litschaueri (Polyporales, Basidiomycota) and its taxonomic positi within the genus. Mycological Progress 11: 415–424. [Google Scholar]
- Viner I, Bortnikov F, Ryvarden L.et al. (2021). On six African species of Lyomyces and Xylodon. Fungal Systematics and Evolution 8: 163–178. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wang C-G, Dai Y-C.(2022). Phylogeny and taxonomy of Spongipellis (Polyporales, Basidiomycota) and its micromorphological similar genera. Mycological Progress 21: 73. [Google Scholar]
- Westhuizen GCAvd.(1963). The cultural characters, structure of the fruit body, and type of interfertility of Cerrena unicolor (Bull. ex Fr.) Murr. Canadian Journal of Botany 41: 1487–1499. [Google Scholar]
- Westphalen MC, Motato-Vásquez V.(2022). A new species of Pseudolagarobasidium from Brazil and new insights on Cerrena (Basidiomycota, Cerrenaceae). Phytotaxa 555: 2. [Google Scholar]
- Westphalen MC, Tomsovsky M, Gugliotta AM.et al. (2019). An overview of Antrodiella and related genera of Polyporales from the Neotropics. Mycologia 111: 813–831. [DOI] [PubMed] [Google Scholar]
- White TJ, Bruns T, Lee S.et al. (1990). Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics. In: Innis MA, Gelfand DH, Sinisky JJ.et al. (eds) PCR protocols, a guide to method and application. Academic Press, San Diego: 315–322. [Google Scholar]
- Wood AR, Ginns J.(2006). A new dieback disease of Acacia cyclops in South Africa caused by Pseudolagarobasidium acaciicola sp. nov. Canadian Journal of Botany 84: 750–758. [Google Scholar]
- Wu F, Chen J-J, Ji X-H.et al. (2018). Phylogeny and diversity of the morphologically similar polypore genera Rigidoporus, Physisporinus, Oxyporus, and Leucophellinus. Mycologia 109: 749–765. [DOI] [PubMed] [Google Scholar]
- Yuan H-S.(2014). Molecular phylogenetic evaluation of Antrodiella and morphologically allied genera in China. Mycological Progress 13: 353–364. [Google Scholar]
- Yuan H-S, Dai Y-C, Steffen K.(2012). Screening and evaluation of white rot fungi to decolourise synthetic dyes, with particular reference to Antrodiella albocinnamomea. Mycology 3: 100–108. [Google Scholar]
- Zhao C-l, Liu S-l, Ren G-j.et al. (2017). Three species of wood-decaying fungi in Polyporales new to China. Mycotaxon 132: 29–42. [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Bayesian consensus tree of Cerrenaceae based on nrDNA ITS and LSU sequences. Countries (and states) are denoted with ISO 3166 codes.
Bayesian consensus tree of the Cerrenaceae based on mitochondrial SSU sequences.
Bayesian consensus tree of the Cerrenaceae based on mitochondrial ATP6 sequences.
Bayesian consensus tree of the Cerrenaceae based on nuclear RPB1 sequences.
Bayesian consensus tree of the Cerrenaceae based on nuclear TEF1 sequences.
