Two new species of Siphocampylus (Campanulaceae, Lobelioideae) from the Central Andes

Laura P Lagomarsino; Daniel Santamaría-Aguilar

doi:10.3897/phytokeys.58.6973

. 2016 Jan 12;(58):105–117. doi: 10.3897/phytokeys.58.6973

Two new species of Siphocampylus (Campanulaceae, Lobelioideae) from the Central Andes

Laura P Lagomarsino ^1,², Daniel Santamaría-Aguilar ²

PMCID: PMC4743019 PMID: 26884710

Abstract Abstract

Two species of Siphocampylus (Campanulaceae: Lobelioideae) from the Central Andes of Peru and Bolivia are described, illustrated, and discussed with reference to related species. One species, Siphocampylus antonellii, is endemic to high elevation grasslands of Calca, Peru, while the second, Siphocampylus siberiensis, is endemic to cloud forests of Cochabamba, Bolivia. Both species are robust shrubs that produce tubular pink flowers that are likely pollinated by hummingbirds.

Keywords: Andean biodiversity hotspot, Asterales, Bolivia, centropogonid clade, Peru, South America, taxonomy

Introduction

While the subfamily Lobelioideae Burnett of Campanulaceae Juss. is cosmopolitan in its distribution, more than half of its ~1200 species are restricted to the Neotropics (Lammers 2007). Most of these species (~550/680) belong to the Andean-centered centropogonid clade, which comprises Burmeistera Triana (~120 species), Centropogon C. Presl (~210 species), and the mainland species of Siphocampylus Pohl (~220 species). This clade is unique within Lobelioideae for its combination of Neotropical distribution, woody habit, entire corolla tube (i.e., neither fenestrate nor dorsally cleft), and floral adaptation to pollination by either hummingbirds or nectar bats (Lagomarsino et al. 2014; Lammers 2002; Muchhala and Lammers 2005). Within the centropogonid clade, Siphocampylus can further be distinguished by its capsular (vs. baccate) fruit. The genus, however, is not monophyletic (Antonelli 2008; Knox et al. 2008): in addition to the Caribbean species, which are distantly related to the centropogonid clade, its mainland species form at least 11 subclades that are polyphyletic with respect to the berry-producing Centropogon (Lagomarsino et al. 2014). This result is not surprising given the high degree of character overlap between Centropogon and Siphocampylus, which has frequently resulted in the incorrect filing of material in herbaria (Gleason 1921; Lammers 1998) and the occasional description of a new species to the incorrect genus or of uncertain placement (e.g., Centropogon dubius [Zahlbr.] E. Wimm. for both scenarios) (Gleason 1921). The non-monophly of these genera is largely due to the dynamic evolution of fruit-type within the clade: fleshy fruits have evolved approximately eight times from dry-fruited ancestors, likely as a result of migration to densely forested habitats (Givnish et al. 2005, 2009; Lagomarsino et al. 2014). While further phylogenetic information is necessary to begin to re-delimit generic boundaries to reflect evolutionary relationships within Neotropical Lobelioideae, Siphocampylus species are easily identified to genus within the confines of the current classification system, especially when fruiting material is available. Despite its non-monophyly, Siphocampylus remains a conspicuous, if poorly studied, component of the cloud forests and high elevation grasslands that comprise much of the tropical Andean global biodiversity hotspot (Myers et al. 2000). Future taxonomic and phylogenetic work focused on the centropogonid clade will undoubtedly result in the description of many new species and discovery of new clades defined by synapomorphies.

Here we describe two new species of hummingbird-pollinated Siphocampylus. Type specimens for both species were included in the most recent molecular phylogeny of the centropogonid clade, which is based on five plastid markers and includes relatively dense taxon sampling that spans all recognized taxonomic divisions, geographical occurrences, and morphological variation within Neotropical Lobelioideae (Lagomarsino et al. 2014). The phylogeny provides the information necessary to discuss these new species in relation to their closest evolutionary relatives. We additionally discuss similarities and differences of the species placed closely to their relatives in the most recent monograph of Siphocampylus (Wimmer 1943, 1953, 1968).

Methods

Field collections focused on Campanulaceae were conducted in Bolivia in November–December, 2011 and in Peru in November–December, 2012. Species identification and description of new species resulting from this fieldwork utilized many taxonomic references (Gleason 1921; Lammers 1998; León and Lammers 2006; Wimmer 1937, 1943, 1953, 1968) and collections at the following herbaria: A, BOLV, GB, GH, LPB, MO, MOL, NY, USM, and USZ. Herbarium acronyms here and throughout follow the Index Herbariorum (Thiers 2013 [continuously updated]).

Taxonomic treatment

Siphocampylus antonellii

Lagom. & D. Santam. sp. nov.

urn:lsid:ipni.org:names:77151883-1

Figs 1 , 2

Figure 1. — *Siphocampylus* *antonellii*. A Flowering branch B Leaf, abaxially, including detail of leaf margin and stellate hairs that cover surface C Staminate-phase flower, including bibracteolate pedicel, with detail of sepal and stellate hairs that cover the outer corolla surface D Longitudinal section of a pistillate-phase flower, showing the insertion of staminal tube to corolla, style and stigma as situated relative to the stamens, and bilocular ovary with axile placentation E Corolla lobe detail F Detail of anther tube, including apical hairs on ventral anthers, and stigma. Drawing by Bobbi Angel from the type.

Figure 2. — *Siphocampylus* *antonellii*. A Habit and high-elevation grassland (puna) habitat B Flowering branch C Cross-section of stem showing woody habit D Adaxial leaf surface E Abaxial leaf surface F Lateral view of flower in staminate phase G Anterior view of a flower, showing corolla aperture. All photos of the type collection, taken in the field by L. Lagomarsino.

Diagnosis.

Siphocampylus antonellii is similar to Siphocampylus elfriedii, but differs in its smaller, linear-oblanceolate leaves, ventral corolla lobe >1.3 cm long, and pleasant, lemon-like odor emitted from living plants.

Type.

Peru. Cusco: Calca, Lares, Calle entre Amaparaes y Suyo, Arriba de Amaparaes, 12°58'902"S, 077°50'W, 3799 m, 10 December 2012 (fl), L. Lagomarsino, D. Santamaría, J. Wells, F. Farro 400 (holotype: A!; isotypes: GB!, MO!, NY!).

Shrub 1.5 m tall, branching 20 cm above the base, with soft wood; branches 0.2–0.6 cm in diameter, solid and fistulose, light brown to reddish purple in living material, glabrescent or white-tomentose; internodes 0.2–1.0 cm long; latex white. Leaves spirally arranged, distributed evenly along the branches, producing lemon-like odor; petiole 0.1–0.5 cm long, sometimes subsessile, villous, the trichomes whitish, adaxially canaliculate, abaxially rounded to triangular; lamina 3.8–5.2 × 0.3–0.55 cm, linear-oblanceolate, not rugose, appearing glabrous but densely pubescent with diminutive, whitish, stellate to echinoid trichomes; base attenuate to decurrent, sometimes with uneven sides; apex acuminate; margin sinuate, subentire, or diminutively dentate, 11–25 teeth per side, rounded to uncinate, sometimes appearing as a glandular callosity; venation reticulate, with 5–10 pairs of lateral nerves, ascending, impressed or indistinct adaxially, flat abaxially. Flowers solitary, axillary, generally towards the apex of branch; pedicel 3.0–5.0 cm long, straight for almost the entire length, but curved below the hypanthium, cylindrical or flattened, densely pubescent, bibracteolate; calyx lobes 5, 0.7–1.6 × 0.1–0.12 cm, linear-oblanceolate, margins diminutively dentate with 3–5 teeth per side, densely pubescent on both surfaces, straight, the apex acuminate; corolla (2.8–) 3.9–5.1 cm long, tube pink with yellow to light green lines parallel to the lobes, lobes light green-yellow externally, light yellow to cream colored inside, completely pubescent externally, pubescent internally with stellate to echinoid trichomes; tube 2.7–3.5 × 0.4–0.6 cm, constricted at the base and widening distally, straight at anthesis; corolla lobes 5, lanceolate to narrowly triangular, apex acute to acuminate, the two dorsal lobes 1.0–1.6 cm long, the two lateral lobes 1.3–1.5 cm long, the ventral lobe 1.4–1.9 cm long; staminal tube 3.5–4.5 × 0.1 cm, straight, glabrous, cream-colored to light green in living material, exserted between the two dorsal lobes; anther tube 0.5–0.7 × 0.2–0.21 cm, dark gray, glabrous, ventral anthers 0.4–0.6 cm long, penicillate at the apex, the trichomes white or yellowish gold, dorsal anther 0.45–0.6 cm long, glabrous. Fruits not seen.

Distribution and habitat.

Siphocampylus antonellii is endemic to Peru, where it grows on rocky slopes in puna habitat at ~3800 m in elevation. It is only known from the type collection.

Phenology.

Individuals were collected in flower in December; the rest of the phenology of this species remains unknown.

Etymology.

It is an honor to name this attractive species for Dr. Alexandre Antonelli (1978–), a biogeographer and phylogeneticist at the University of Gothenburg. Antonelli has made many important contributions to our understanding of Neotropical biodiversity through space and time, and to the evolution of various taxa, including Lobelioideae. His efforts in the latter brought the second author to the field in Costa Rica in 2005 in search of Campanulaceae, and helped to inspire the first author to study Centropogon, Siphocampylus, and Burmeistera.

Conservation status.

Siphocampylus antonellii is endemic to a narrow stretch of high-elevation grassland (puna) in Calca, Peru, where it is locally abundant. Only a single population of this species is known, from which the type collection was made. Due to its small area of occurrence and the threat of future deforestation in its habitat, we tentatively consider this species to be Vulnerable (IUCN 2014). Its vulnerable status is further justified by its roadside occurrence, near major construction efforts.

Discussion.

Siphocampylus antonellii is most similar to Siphocampylus elfriedii E. Wimm. (Fig. 3C) and Siphocampylus parvifolius E. Wimm., which are both also endemic to Peru. These species share a shrubby habit (Fig. 2A), generally high elevation occurrence ([1050–] 2100–3800 m), bibracteolate pedicels (Figs 1C, 2F), pink or pinkish-purple corolla tubes with yellow-green lobes (Figs 2F–G, 3C), glabrous anthers (except at the apex of the ventral anthers) (Figs 1F, 3C), and turbinate ovaries (Figs 1C, 2F, 3C). Both Siphocampylus antonellii and Siphocampylus elfriedii produce echinoid trichomes, following Batterman and Lammers 2004. However, Siphocampylus antonellii can be easily distinguished by the differences enumerated in Table 1 and by the agreeable lemon-like smell that it emits.

Figure 3. — Closest relatives of *Siphocampylus* *antonellii*, based on molecular phylogeny of Lagomarsino et al. (2014). A Flower of *Siphocampylus* *veteranus* B Flower of *Siphocampylus* *actinothrix* C Flower of *Siphocampylus* *elfriedii* D Cross-section of main stem of *Siphocampylus* *veteranus*, showing a much more robust habit than *Siphocampylus* *antonellii*, but similar wood structure. All photos taken in the field by L. Lagomarsino. A, D *L. Lagomarsino et al. 388* B *L. Lagomarsino et al. 403* C *L. Lagomarsino et al. 387*.

Table 1.

Differences between Siphocampylus antonellii, Siphocampylus elfriedii, and Siphocampylus parvifolius.

	Siphocampylus antonellii	Siphocampylus elfriedii	Siphocampylus parvifolius
Leaf shape	Linear-oblanceolate	Lanceolate	Lanceolate to oblanceolate
Leaf size	3.8–5.2 × 0.3–0.55 cm	5.0–7.4 × 1.1–1.9 cm	2.0 × 0.5 cm
Leaf margin	Margin sinuate, subentire, or diminutively dentate	Denticulate	Weakly crenulate
Sepal length	0.7–1.6 cm	0.7–1.4 cm	0.3 cm long
Sepal margin	Diminutively dentate	Denticulate	Entire or diminutively denticulate
Corolla length	(2.8–) 3.9–5.1 cm	3.9–4.6 cm	3.4 cm
Corolla indument	Pubescent	Pubescent	Glabrous
Dorsal corolla lobe length	1.0–1.6 cm	0.9–1.2 cm	1.1–1.4 cm
Ventral corolla lobe length	1.4–1.9 cm	0.5–1 cm	0.9–1.2 cm
Reference sheets	L. Lagomarsino 400 (A)	L. Lagomarsino 387 (GH); J. L. Luteyn & M. L. Lebrón-Luteyn 6395 (MO); F. W. Pennell 13841 (GH); T. Plowman & E. W. Davis 5126 (GH); J. West 7045 (GH)	R. D. Metcalf 30469 (A)

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This new species would be placed near Siphocampylus nobilis E. Wimm. and Siphocampylus rosmarinifolius G. Don in the dichotomous key of genus in Wimmer (1953). In addition to being restricted to Peru, these species share linear leaves, turbinate ovaries, and narrow corolla lobes. However, these two species have glabrous sepals and corolla (vs. pubescent in Siphocampylus antonellii), ebracteolate, glabrous pedicels (vs. bibracteolate and pubescent), and different corolla colors: reddish orange with yellow lobes in Siphocampylus rosmarinifolius and purple in Siphocampylus nobilis (vs. pink with yellow-green lobes [Fig. 2F]). Siphocampylus nobilis can be further distinguished from Siphocampylus antonellii by its vining habit (vs. shrubby), long, narrow leaves (6.0–8.0 × 0.2–0.3 vs. 3.8–5.2 × 0.3–0.55 cm), and glabrous branches, leaves, pedicels, and hypanthium (vs. pubescent [Fig. 1]). Siphocampylus rosmarinfolius can be further distinguished by its longer leaves (8.0–11.5 cm vs. 3.8–5.2 cm), the rugose, glabrous adaxial leaf surface (vs. not rugose and pubescent), and revolute leaf margins (vs. not revolute).

Molecular phylogenetic analysis places Siphocampylus antonellii in a well-supported clade that includes Siphocampylus actinotrix E. Wimm. (Fig. 3B), Siphocampylus elfriedii (Fig. 3C), Siphocampylus vatkeanus Zahlbr., Siphocampylus veteranus E. Wimm. (Fig. 3A, D), and Siphocampylus rictus Lammers; within this clade, Siphocampylus antonellii is sister to Siphocampylus veteranus (Lagomarsino et al. 2014). This clade as a whole is composed of generally tall, woody shrubs. The placement of Siphocampylus elfriedii in this clade is not surprising, as it is quite similar to Siphocampylus antonellii (see above). However, it is more difficult to find similarities with the remaining species, which can be easily distinguished from Siphocampylus antonellii by a series of putative adaptations to pollination by bats: long pedicels (7.0–15 cm), wide corolla apertures, and longer corollas (3.2–5.0 cm) that are generally dull in color (either green, cream-colored, white or yellowish, sometimes mottled with reddish pigmentation) (Fig. 3A–B). Additionally, these species have longer leaves (6.0–13.5 cm vs. 3.8–5.2 cm) and a glabrous or only sparsely pubescent corolla (but with echinoid-stellate pubescence in Siphocampylus actinothrix [Fig. 3B]). Despite the similarities discussed above, Siphocampylus rosmarinifolius falls outside of the clade that includes Siphocampylus antonellii (Lagomarsino et al. 2014); Siphocampylus nobilis and Siphocampylus parvifolius have not yet been sampled in a molecular phylogenetic analysis.