A key to 87 accepted species of Xylodon
1a. Hymenophore odontioid or coralloid........................................................................................................................................	2
b. Hymenophore smooth, tuberculate, grandinioid, irpicoid or poroid....................................................................................	66
2a. Capitate or subcapitate cystidia or cystidioles present............................................................................................................	3
b. Capitate or subcapitate cystidia or cystidioles absent..............................................................................................................	38
3a. Basidiospores ellipsoid................................................................................................................................................................	4
b. Basidiospores globose to subglobose, ovoid, cylindrical or allantoid....................................................................................	24
4a. Moniliform or submoniliform cystidia present........................................................................................................................	5
b. Moniliform or submoniliform cystidia absent..........................................................................................................................	11
5a. Basidiospores thin-walled...........................................................................................................................................................	6
b. Basidiospores thick-walled...........................................................................................................................................................	9
6a. Basidiospores up to 7.5 μm long......................................................................................................................	X. anmashanensis
b. Basidiospores up to 6 μm long......................................................................................................................................................	7
7a. Moniliform cystidia originating only in subhymenium.....................................................................................	X. spathulatus
b. Moniliform cystidia originating only in subiculum or in subiculum and subhymenium.....................................................	8
8a. Aculei up to 1 mm long, hymenophoral margin thinning out.............................................................................	X. brevisetus
b. Aculei up to 0.3 mm long, hymenophoral margin abrupt or byssoid.................................................................	X. subclavatus
9a. Astrocystidia present; basidiospores cyanophilous............................................................................................	X. ussuriensis
b. Astrocystidia absent; basidiospores acyanophilous................................................................................................................	10
10a. Hyphoid or subulate cystidia absent.................................................................................................................	X. crassisporus
b. Hyphoid or subulate cystidia present...............................................................................................................	X. anmashanensis
11a. Hymenophore coralloid...............................................................................................................................................	X. archeri
b. Hymenophore odontioid.............................................................................................................................................................	12
12a. Basidia cylindrical to subcylindrical.......................................................................................................................................	13
b. Basidia utriform............................................................................................................................................................................	15
13a. Pin- or sting-shaped cystidia present........................................................................................................................	X. borealis
b. Pin- or sting-shaped cystidia absent...........................................................................................................................................	14
14a. Aculei 0.03–0.12 mm long, 8–14 per mm; basidiospores thin- or slightly thick-walled............................	X. pseudolanatus
b. Aculei 0.13–0.35 mm long, 4 per mm; basidiospores thin-walled........................................................................	X. vesiculosus
15a. Astrocystidia present.....................................................................................................................................	X. astrocystidiatus
b. Astrocystidia absent.....................................................................................................................................................................	16
16a. Only capitate cystidia and leptocystidia present......................................................................................	X. heterocystidiatus
b. Different combinations of cystidia.............................................................................................................................................	17
17a. Besides capitate to subcapitate cystidia, tramacystidia, subulate or apically encrusted hyphoid cystidia present........................................................................................................................................................................................	18
b. Only capitate cystidia present.....................................................................................................................................................	22
18a. Tramacystidia present..............................................................................................................................................................	19
b. Tramacystidia absent...................................................................................................................................................................	20
19a. Capitate cystidia slightly thick-walled; basidiospores thick-walled, more than 4 µm wide........................	X. magnificus
b. Capitate cystidia thin-walled; basidiospores thin-walled, less than 4 µm wide......................................................	X. lanatus
20a. Subulate cystidia present.......................................................................................................................................	X. pruniaceus
b. Subulate cystidia absent...............................................................................................................................................................	21
21a. Hymenophore cream; hyphoid cystidia sometimes with stellate crystalline cap..........................................	X. attenuatus
b. Hymenophore white; hyphoid cystidia often heavily encrusted and rarely with stellate crystalline cap.....	X. crystalliger
22a. Basidia subclavate.....................................................................................................................................................	X. capitatus
b. Basidia sinuous or utriform.........................................................................................................................................................	23
23a. Basidiospores thin-walled, more than 3.5 µm wide.................................................................................................	X. asperus
b. Basidiospores slightly thick-walled, less than 3.5 µm wide.............................................................................	X. kunmingensis
24a. Hymenophore coralloid or odontioid with fimbriate aculei...............................................................................................	25
b. Hymenophore odontioid without fimbriate aculei..................................................................................................................	28
25a. Aculei up to 3 mm long............................................................................................................................................	X. quercinus
b. Aculei up to 1 mm long................................................................................................................................................................	26
26a. Basidiospores more than 3 μm wide...........................................................................................................................	X. archeri
b. Basidiospores less than 3 μm wide.............................................................................................................................................	27
27a. Aculei up to 200 μm long; basidiospores less than 6 μm long................................................................................	X. nesporii
b. Aculei up to 600 μm long; basidiospores more than 6 μm long................................................................................	X. ramicida
28a. Basidiospores more than 7 μm long........................................................................................................................................	29
b. Basidiospores less than 7 μm long..............................................................................................................................................	30
29a. Basidiospores ovoid to allantoid, less than 5 µm wide..................................................................................	X. adhaerisporus
b. Basidiospores globose to subglobose, more than 5 µm wide..........................................................................................	X. follis
30a. Basidiospores slightly thick-walled........................................................................................................................................	31
b. Basidiospores thin-walled...........................................................................................................................................................	32
31a. Pin- or sting-like cystidia abundant; basidiospores slightly cylindrical, ellipsoid or broadly ellipsoid...........	X. borealis
b. Pin- or sting-like cystidia absent; basidiospores globose or subglobose.......................................................	X. hyphodontinus
32a. Basidiospores cylindrical or subcylindrical.....................................................................................................	X. rimosissimus
b. Basidiospores differently shaped...............................................................................................................................................	33
33a. Moniliform cystidia scattered..............................................................................................................................	X. subclavatus
b. Moniliform cystidia absent..........................................................................................................................................................	34
34a. Fusiform cystidia present in aculei............................................................................................................................	X. hastifer
b. Fusiform cystidia absent..............................................................................................................................................................	35
35a. Basidiospores less than 5 μm long..........................................................................................................................................	36
b. Basidiospores more than 5 μm long...........................................................................................................................................	37
36a. Subcylindrical and hyphoid to narrowly ventricose cystidia absent....................................................................	X. tenellus
b. Subcylindrical and hyphoid to narrowly ventricose cystidia present......................................................................	X. filicinus
37a. Capitate cystidia in hymenium and subhymenium, capitate hyphal endings in subiculum and aculei…......	X. asperus
b. Capitate gloeocystidia or hyphal endings only in hymenium and/or aculei.........................................................	X. capitatus
38a. Subulate cystidia present.........................................................................................................................................................	39
b. Subulate cystidia absent...............................................................................................................................................................	48
39a. Basidiospores ellipsoid or narrowly ellipsoid.......................................................................................................................	40
b. Basidiospores cylindrical, allantoid, ovoid or subglobose......................................................................................................	45
40a. Leptocystidia present.................................................................................................................................................	X. australis
b. Leptocystidia absent....................................................................................................................................................................	41
41a. Hyphoid and moniliform to submoniliform cystidia present....................................................................	X. anmashanensis
b. Hyphoid and moniliform to submoniliform cystidia absent..................................................................................................	42
42a. Basidiospores often glued together in packs of two to six basidiospores...................................................	X. candidissimus
b. Basidiospores separated..............................................................................................................................................................	43
43a. Subulate cystidia thin- or slightly thick-walled, less than 30 μm long......................................................	X. submucronatus
b. Subulate cystidia thin-walled, more than 30 μm long..............................................................................................................	44
44a. Basidia utriform with one or two constrictions; subulate cystidia up to 75 μm long.....................................	X. knysnanus
b. Basidia utriform to galzinoid with several constrictions; subulate cystidia up to 50 μm long...........................	X. nudisetus
45a. Basidiospores ovoid to allantoid, more than 7 μm long................................................................................	X. adhaerisporus
b. Basidiospores cylindrical or subglobose, less than 7 μm long................................................................................................	46
46a. Hymenophore greyish-white to yellowish; subulate cystidia or hyphal endings................................	X. crustosoglobosus
b. Hymenophore white to cream; subulate cystidia up to 50 or 75 μm long..............................................................................	47
47a. Basidia utriform with one or two constrictions; subulate cystidia up to 75 μm long.....................................	X. knysnanus
b. Basidia utriform to galzinoid with several constrictions; subulate cystidia up to 50 μm long...........................	X. nudisetus
48a. Moniliform or submoniliform cystidia present....................................................................................................................	49
b. Moniliform or submoniliform cystidia absent..........................................................................................................................	51
49a. Only moniliform cystidia present...................................................................................................................................	X. lenis
b. Other types of cystidia present....................................................................................................................................................	50
50a. Hyphoid cystidia and rare capitate cystidioles present..............................................................................	X. anmashanensis
b. Cylindrical gloeocystidia and subclavate cystidia present.............................................................................	X. subscopinellus
51a. Basidiospores suballantoid or subglobose.............................................................................................................................	52
b. Basidiospores ellipsoid or cylindrical........................................................................................................................................	54
52a. Basidiospores suballantoid, more than 6 µm long.................................................................................................	X. syringae
b. Basidiospores subglobose, less than 6 µm long........................................................................................................................	53
53a. Capitate hyphal endings present in aculei....................................................................................................................	X. rudis
b. Capitate hyphal endings absent..............................................................................................................................	X. subglobosus
54a. Cystidia or cystidioles absent..................................................................................................................................................	55
b. Cystidia or cystidioles present....................................................................................................................................................	56
55a. Basidiospores narrowly ellipsoid to cylindrical, more than 6 µm long, less than 3 µm wide.........................	X. nesporina
b. Basidiospores ellipsoid, less than 6 µm long, more than 3 µm wide...............................................................	X. mussooriensis
56a. Cylindrical, clavate to subclavate, spathuliform cystidia or leptocystidia present..........................................................	57
b. Tubular, ventricose, pyriform, hyphoid or sinuous cystidia present.....................................................................................	60
57a. Clavate to spathuliform cystidia present...............................................................................................................................	58
b. Clavate to spathuliform cystidia absent.....................................................................................................................................	59
58a. Hymenophore greyish-white or pale cream; basidiospores thick-walled, more than 4 µm wide.................	X. pruinosus
b. Hymenophore cinnamon to orange-brown; basidiospores thin-walled, less than 4 µm wide......................	X. yunnanensis
59a. Cylindrical gloeocystidia and subclavate cystidia.......................................................................................	X. subscopinellus
b. Leptocystidia present with encrustation.........................................................................................................	X. rhododendricola
60a. Tubular cystidia present..........................................................................................................................................................	61
b. Tubular cystidia absent................................................................................................................................................................	62
61a. Tubular cystidia thick-walled, slightly flexuous; basidia with two or rarely four sterigmata; basidiospores slightly thick-walled...............................................................................................................................................................	X. echinatus
b. Tubular tramacystidia thin-walled, snake-like sinuous; basidia with four sterigmata; basidiospores thin-walled...........................................................................................................................................................	X. subserpentiformis
62a. Pyriform cystidia present.........................................................................................................................................	X. pelliculae
b. Pyriform cystidia absent..............................................................................................................................................................	63
63a. Ventricose cystidia present............................................................................................................................	X. submucronatus
b. Ventricose cystidia absent...........................................................................................................................................................	64
64a. Basidiospores more than 6 μm long........................................................................................................................	X. lutescens
b. Basidiospores less than 6 μm long..............................................................................................................................................	65
65a. Basidiospores more than 3.5 µm wide...........................................................................................................................	X. rudis
b. Basidiospores less than 3.5 µm wide.........................................................................................................................	X. papillosus
66a. Hymenophore irpicoid or poroid...........................................................................................................................................	67
b. Hymenophore smooth, tuberculate or grandinioid.................................................................................................................	89
67a. Cystidia absent….....................................................................................................................................................	X. nongravis
b. Cystidia present............................................................................................................................................................................	68
68a. Moniliform or submoniliform cystidia present....................................................................................................................	69
b. Moniliform or submoniliform cystidia absent..........................................................................................................................	72
69a. Hymenophore irpicoid.............................................................................................................................................................	70
b. Hymenophore poroid..................................................................................................................................................................	71
70a. Hyphoid or subulate cystidia present mostly in aculei...............................................................................	X. anmashanensis
b. Hyphoid or subulate cystidia absent......................................................................................................................	X. spathulatus
71a. Basidiospores ellipsoid, less than 5.5 μm long.....................................................................................................	X. bresinskyi
b. Basidiospores suballantoid, more than 7.5 μm long..................................................................................................	X. syringae
72a. Basidiospores more than 6.5 μm long.....................................................................................................................................	73
b. Basidiospores less than 6.5 μm long...........................................................................................................................................	74
73a. Pores less than 1 mm in diam; cystidia capitate; basidiospores less than 8 µm long........................................	X. nothofagi
b. Pores more than 1 mm in diam; cystidia not capitate; basidiospores mostly more than 8 µm long.....................	X. syringae
74a. Basidia with two sterigmata...............................................................................................................................	X. crassihyphus
b. Basidia with four sterigmata.......................................................................................................................................................	75
75a. Hymenophore pileate; hyphal system trimitic..................................................................................................	X. trametoides
b. Hymenophore resupinate or effused-reflected; hyphal system monomitic to dimitic........................................................	76
76a. Subulate or cylindrical cystidia present.................................................................................................................................	77
b. Subulate or cylindrical cystidia absent.......................................................................................................................................	79
77a. Basidiospores broadly ellipsoid to subglobose, more than 4 μm wide........................................................	X. apacheriensis
b. Basidiospores ellipsoid, less than 4 μm wide............................................................................................................................	78
78a. Basidiospores more than 5 µm long........................................................................................................................	X. niemelaei
b. Basidiospores less than 5 µm long........................................................................................................................	X. subflaviporus
79a. Bottle-shaped cystidia present, apically with large rhomboid crystals...........................................................	X. cystidiatus
b. Bottle-shaped cystidia absent......................................................................................................................................................	80
80a. Hyphae without clamp connections.........................................................................................................	X. poroideoefibulatus
b. Hyphae with clamp connections................................................................................................................................................	81
81a. Capitate cystidia mostly bladder-like....................................................................................................................................	82
b. Capitate cystidia not bladder-like...............................................................................................................................................	83
82a. Basidia barrel-shaped to pyriform; basidiospores ellipsoid, less than 3.2 μm wide................................	X. pseudotropicus
b. Basidia utriform to clavate; basidiospores broadly ellipsoid, more than 3.2 µm wide....................................	X. mollissimus
83a. Basidiospores subglobose or ovoid........................................................................................................................................	84
b. Basidiospores ellipsoid................................................................................................................................................................	85
84a. Basidiospores subglobose, more than 4 µm wide.............................................................................................	X. hallenbergii
b. Basidiospores ovoid, less than 4 µm wide................................................................................................................	X. flaviporus
85a. Growth on palm or fern as substrate; capitate cystidia rare....................................................................................	X. gracilis
b. Growth on angiosperms or gymnosperms; capitate cystidia not rare...................................................................................	86
86a. Basidiospores more than 5.5 μm long...................................................................................................................	X. paradoxus
b. Basidiospores less than 5.5 μm long...........................................................................................................................................	87
87a. Hymenophore cream...........................................................................................................................................	X. taiwanianus
b. Hymenophore orange, rose or buff............................................................................................................................................	88
88a. Hymenophore beige to slightly orange; capitate cystidia not encrusted.......................................................	X. subtropicus
b. Hymenophore cream, pinkish cream or buff; capitate cystidia partly encrusted with brownish yellow resinous material......................................................................................................................................................................	X. ovisporus
89a. Basidia with two sterigmata......................................................................................................................................	X. bisporus
b. Basidia with four sterigmata.......................................................................................................................................................	90
90a. Capitate or subcapitate cystidia present................................................................................................................................	91
b. Capitate or subcapitate cystidia absent....................................................................................................................................	106
91a. Spores globose to subglobose..................................................................................................................................................	92
b. Spores cylindrical, ellipsoid to broadly ellipsoid......................................................................................................................	94
92a. Hymenophore smooth..............................................................................................................................................	X. pumilius
b. Hymenophore grandinioid.........................................................................................................................................................	93
93a. Capitate cystidia rare; basidiospores less than 4.5 μm long...................................................................................	X. tenellus
b. Capitate cystidia not rare; basidiospores more than 4.5 μm long..................................................................	X. hyphodontinus
94a. Gloeocystidia present..........................................................................................................................................	X. tuberculatus
b. Gloeocystidia absent....................................................................................................................................................................	95
95a. Tramacystidia present...........................................................................................................................................	X. verecundus
b. Tramacystidia absent...................................................................................................................................................................	96
96a. Basidiospores thick-walled......................................................................................................................................................	97
b. Basidiospores thin-walled.........................................................................................................................................................	100
97a. Basidiospores less than 3.5 µm wide.............................................................................................................................	X. rickii
b. Basidiospores more than 3.5 µm wide.......................................................................................................................................	98
98a. Hymenophore smooth..............................................................................................................................................	X. pumilius
b. Hymenophore grandinioid.........................................................................................................................................................	99
99a. Astrocystidia and submoniliform cystidia present, septocystidia absent......................................................	X. ussuriensis
b. Astrocystidia and submoniliform cystidia absent, septocystidia present..................................................	X. septocystidiatus
100a. Only capitate cystidia present.............................................................................................................................................	101
b. Besides capitate cystidia, other types of cystidia present......................................................................................................	102
101a. Hyphae not encrusted; cystidia with exudation; basidiospores cylindrical to subcylindrical................	X. rimosissimus
b. Hyphae sometimes encrusted; cystidia without exudation; basidiospores ellipsoid.........................................	X. yarraensis
102a. Basidiospores less than 3.5 μm wide..................................................................................................................................	103
b. Basidiospores more than 3.5 μm wide.....................................................................................................................................	105
103a. Cystidia not encrusted................................................................................................................................	X. heterocystidiatus
b. Cystidia strongly encrusted......................................................................................................................................................	104
104a. Basidiospores broadly ellipsoid, less than 5 µm long.........................................................................................	X. erikssonii
b. Basidiospores cylindrical to subcylindrical, more than 5 µm long......................................................................	X. gamundiae
105a. Hyphoid cystidia absent, lageniform, clavate and cylindrical cystidia present...........................................	X. hjortstamii
b. Hyphoid cystidia present, lageniform, clavate and cylindrical cystidia absent.................................................	X. attenuatus
106a. Gloeocystidia present........................................................................................................................................	X. tuberculatus
b. Gloeocystidia absent..................................................................................................................................................................	107
107a. Basidiospores globose to subglobose.................................................................................................................................	108
b. Basidiospores ellipsoid or cylindrical......................................................................................................................................	109
108a. Subulate cystidia or hyphal endings present, leptocystidia absent; basidiospores more than 5 µm long, more than 3.8 µm wide...................................................................................................................................................	X. crustosoglobosus
b. Subulate cystidia or hyphal endings absent, leptocystidia present; basidiospores more than 5 µm long, more than 3.8 µm wide..................................................................................................................................................................	X. victoriensis
109a. Cystidia absent......................................................................................................................................................................	110
b. Cystidia present..........................................................................................................................................................................	112
110a. Cystidioles absent...............................................................................................................................................	X. acystidiatus
b. Cystidioles present.....................................................................................................................................................................	111
111a. Basidiospores less than 5 µm long.......................................................................................................................	X. papillosus
b. Basidiospores more than 5 µm long....................................................................................................................	X. tenuicystidius
112a. Snake-like sinuous tubular tramacystidia present...........................................................................................................	113
b. Tubular tramacystidia absent...................................................................................................................................................	114
113a. Hymenial hyphae encrusted..........................................................................................................................	X. serpentiformis
b. Hymenial hyphae not encrusted...................................................................................................................	X. subserpentiformis
114a. Subulate cystidia present........................................................................................................................................	X. australis
b. Subulate cystidia absent.............................................................................................................................................................	115
115a. Basidiospores more than 4 µm wide....................................................................................................................	X. pruinosus
b. Basidiospores less than 4 µm wide...........................................................................................................................................	116
116a. Clavate-sinuous to submoniliform cystidia present; basidiospores narrowly ellipsoid.....................	X. damansaraensis
b. Clavate-sinuous to submoniliform cystidia absent, basidiospores ellipsoid to broadly ellipsoid...................................	117
117a. Leptocystidia and lagenocystidia absent, cylindrical to clavate cystidia and astrocystidia present............	X. detriticus
b. Leptocystidia and lagenocystidia present, cylindrical to clavate cystidia and astrocystidia absent......	X. lagenicystidiatus