Keys to Corticioid Genera
Thanks to Dr. Sergio Pérez Gorjón for creating these dichotomous keys to corticioid genera and permitting their inclusion on CrustFungi.Com. The keys below are slightly updated from their original publication in 2020. Start with the main key to be guided to more specific keys for groups of morphologically similar genera.
Main Key
11A.
Spores ornamented and/or branched, lobed or tetrahedral (easily seen in Melzer's reagent!)
Key K
Key A: Pseudostipitate to Stipitate Crust-like Fungi
Basidiome pseudostipitate to stipitate and pileate.
3A.
Spores amyloid
Auriscalpium
3B.
Spores non-amyloid
Hydnodon (see also Trechispora)
4A.
Basidiome fragile, basidia 6-sterigmate, hyphae with abundant oily contents
Sistotrema
5A.
Hyphal system monomitic, gloeocystidia absent
Mycoleptodonoides
5B.
Hyphal system dimitic, gloeocystidia usually present
Mycorrhaphium
6A.
Basidiome infundibuliform, with a hollow stipe
Parastereopsis
8B.
Cystidia absent (cystidiols or gloeocystidia may be present but embedded or little differentiated)
10
9A.
Cystidia non-capitate, basidiome usually on soil
Cotylidia
9B.
Cystidia capitate, basidiome on living mosses
Muscinupta
10A.
Basidiome white, obconical to discoid with a central stipe
Caripia
11A.
Coralloid hyphae present in the pileal surface and stipe
Coralloderma
12A.
Basidiome with a lichenized structure
Cyphellostereum
13A.
Hymenophore merulioid, spores thick-walled
Podoserpula
13B.
Hymenophore smooth to rugose, spores thin-walled
Stereopsis
15A.
Hyphae inflated in context, cystidia absent
Inflatostereum
15B.
Hyphae non-inflated, cystidia encrusted and gloeocystidia present
Cymatoderma
16A.
Hyphal system trimitic, gloeocystidia absent
Aquascypha
17A.
Generative hyphae simple-septate, binding hyphae dextrinoid, spores amyloid
Dichopleuropus
17B.
Generative hyphae clamped, skeletal hyphae non-dextrinoid, spores non-amyloid
Podoscypha
Key B: Resupinate Polypores
Basidiome usually sessile and resupinate to pileate, hymenophore poroid with lacerate pores or with anastomosing ridges.
1A.
Basidiome brown, becoming black in KOH, generative hyphae with simple septa, setae present or absent
2
2A.
Basidiome perennial, hard, hyphal system dimitic
Phellinus s.l.
2B.
Basidiome annual, soft, and fragile when dry, hyphal system monomitic
Inonotus s.l.
3A.
Pores developing from an apical pore in isolated papillae
Porotheleum (=Stromatoscypha)
6A.
Hymenophore with irregular pores, substrate reddened
Porogramme
6B.
Hymenophore with long anastomosing ridges, substrate not reddened
Hymenogramme
7A.
Basidiospores thick-walled, with dextrinoid arboriform hyphae
Grammothelopsis
8A.
Skeletal hyphae present, darkening with age and dextrinoid
Grammothele
8B.
Arboriform hyphae present, not darkening with age, non-dextrinoid
Theleporus
12A.
Margin rhizomorphic, causing a white rot
Anomoloma
12B.
Margin not rhizomorphic, causing a brown rot
Anomoporia
13A.
Generative hyphae with simple septa or alternating multiple clamps connections
Amylosporus
14A.
Pores labyrinthine to daedaleoid
Amylonotus
16A.
Cystidia apically encrusted
Larssoniporia
16B.
Cystidia smooth
Wrightoporiopsis
17A.
Basidiome membranous to cottony, margin usually with rhizomorphs
Wrightoporia
17B.
Basidiome corky, margin without rhizomorphs
Pseudowrightoporia
18B.
Hyphal system dimitic
Perenniporia
20A.
Spore ornamentation rough, formed by longitudinal striae or rounded ridges
Haploporus (=Pachykytospora)
21B.
Hyphal system dimitic, generative hyphae with simple septa
Heterobasidion
22A.
Basidiospores yellowish to brown
Lenzitopsis
23A.
Hyphae usually ampullate at septa (check subicular hyphae), basidia with no cyanophilous granulation
Trechispora
23B.
Hyphae not ampullate at septa, basidia with cyanophilous granulation
Lindtneria
27A.
Basidiome white to cream, not changing in KOH, causing a white rot
Leucophellinus
27B.
Basidiome orange to red, red in KOH, causing a brown rot
Pycnoporellus
28A.
Hymenial surface brown to purplish, spores cylindrical
Castanoporus
29A.
Hymenial surface vivid orange to dark colored, mucronate cystidiols present
Rigidoporus
30A.
Hymenial surface with yellow brown colors, effused-reflexed to pileate
Oxychaete
31A.
Hyphal system monomitic, hyphae slightly amyloid
Emmia
31B.
Hyphal system dimitic or pseudodimitic, hyphae not amyloid
Oxyporus
33A.
Basidiospores thick-walled
Byssoporia
35A.
Hyphae dextrinoid
Phlebiporia
35B.
Hyphae slightly amyloid (some hyphae with scattered clamps)
Elaphroporia
37A.
Basidiome resupinate to pileate, coriaceous, basal hyphae thick-walled
Rigidoporus
37B.
Basidiome resupinate, ceraceous, basal hyphae thin-walled
Physisporinus
39A.
Pore surface white to buff, anamorph present, basidiospores allantoid
Riopa
40A.
Hymenophore merulioid with shallow pits, basidiome thin, not pileate
Meruliopsis
40B.
Hymenophore typically poroid, basidiome fleshy, often pileate
Leptoporus
41A.
Skeletal hyphae present
Wolfiporia
41B.
Binding hyphae or sclerified tortuous generative hyphae present
Macrohyporia
44A.
Gloeocystidia with oily contents
Antella
45A.
Hymenophore poroid to lamellate, with brown colors, causing a brown rot
Gloeophyllum s.l.
46A.
Basidiome white, cystidia cylindric, spores narrowly allantoid
Kneiffiella (=Chaetoporellus)
46B.
Basidiome yellow to straw-colored, cystidia hypha-like, spores ellipsoid
Luteoporia
47A.
With two types of cystidia: 1) tramal thick-walled encrusted cystidia, 2) gloeocystidia
Butyrea
48A.
Causing a brown rot
Auriporia
50A.
Basidiome waxy when fresh and resinous when dry
Cerarioporia
51A.
Hymenial surface with violet shades, hyphal system dimitic
Trichaptum
51B.
Hymenial surface with no violet shades, hyphal system monomitic
Xylodon
52A.
Hymenial surface vivid chrome yellow
Flaviporus
53A.
Hymenial surface reddish when bruised, skeletal hyphae metachromatic
Geesterania
54A.
Basidiome brown, with a sweet smell
Metuloidea
54B.
Basidiome usually not brown, with no sweet smell
Steccherinum (=Junghuhnia)
56A.
Basidia distinctly pleural
Radulotubus
57A.
Basidia urniform, with 4–8 sterigmata, hyphae with oily contents, usually ampullate
Sistotrema
57B.
Basidia clavate or cylindrical, with 4 sterigmata, hyphae not ampullate and with no oily contents
58
59A.
Pore surface whitish, stained dark brown to black when bruised
Atraporiella
60A.
Hymenophore pink to reddish and more or less gelatinous, pore partitions fertile
Gloeoporus (see also Vitreoporus)
61A.
Basidiome changing red in KOH
Aurantiporus (see also Erastia)
62A.
Basidiospores globose, broad bottle-shaped cystidiols
Obba
63A.
Basidiospores allantoid, hyphae swelling and gelatinized in KOH
Gelatoporia
63B.
Basidiospores cylindrical, hyphae not swelling and gelatinized in KOH
Sebipora
64A.
Basidiome with rhizomorphs, hyphae encrusted
Porpomyces
65A.
Basidiome usually changing red or purple in KOH
Hapalopilus (see also Erastia)
66A.
Basidiome reddening after bruising, with skeletoid hyphae
Pouzaroporia
67A.
Basidiospores globose
Physisporinus
69A.
Basidiospores allantoid, hyphae thick-walled, irregularly inflated and constricted
Aegis
69B.
Basidiospores subglobose, hyphae thin-walled, with ampullaceous septa
Caudicicola
72A.
Basidiospores globose to subglobose
Niemelaea
72B.
Basidiospores ellipsoid to cylindrical
Ceriporiopsis (see also Frantisekia, Raduliporus, Resiniporus)
73A.
Tubes white to yellowish
Tyromyces
74A.
Basidiome soft, very brittle when dry, basidiospores allantoid
Fragiliporia
74B.
Basidiome corky, basidiospores cylindrical
Bjerkandera
75A.
Basidiome mostly white to yellowish
Postia
75B.
Basidiome pinkish to red
Rhodonia
77A.
Skeletal hyphae dextrinoid
Megasporoporia
78A.
Skeleto-binding hyphae in context arboriform, resinous orange substance in context
Gloeoporellus
78B.
No arboriform skeletal hyphae, resinous substance in context absent
Cyanotrama
81A.
Causing a brown rot
Amyloporia
82A.
Basidiospores allantoid, thin-walled
Cinereomyces (=Canopora?)
82B.
Basidiospores ellipsoid, thick-walled
Yuchengia (see also Amylosporia)
83A.
Substrate reddened in zones
Tinctoporellus
84A.
Basidiospores negative in Melzer's reagent
Megasporia
84B.
Basidiospores with a variable dextrinoid reaction
Perenniporia
86A.
Thick-walled hyphae with sparse clamps, metachromatic
Rickiopora
86B.
Skeletal hyphae present only in context, not metachromatic
Frantisekia
88A.
Hymenophore poroid, daedaleoid to lamellate, causing a brown rot
Gloeophyllum s.l.
90A.
Dendrohyphidia present in the pore partitions, basidiospores cylindrical
Neodatronia
90B.
Dendrohyphidia absent, basidiospores ellipsoid
Donkioporia
91A.
Context rusty brown, no black line between context and tomentum, binding hyphae present
Funalia
92A.
On conifers, basidiospores allantoid, 3–4 µm long
Piloporia
93A.
Dendrohyphidia present in the pore partitions
Datronia
93B.
Dendrohyphidia absent in the pore partitions
Datroniella
94A.
Hyphal system trimitic, with skeletal and binding hyphae
Earliella
95A.
With binding arboriform vegetative hyphae, dichotomously branched
Dichomitus (see also Szczepkamyces)
98A.
Pores round to lacerate to hydnaceous, basidiospores ellipsoid
Xylodon (=Schizopora)
98B.
Pores usually round, small, basidiospores allantoid to cylindrical
Skeletocutis
99A.
Basidiospores ellipsoid to cylindrical, usually up to 5 µm long
Antrodiella
100A.
Basidiospores allantoid to cylindrical, basidiome tough
Diplomitoporus
100B.
Basidiospores ellipsoid, basidiome soft
Cinereomycetella
101A.
Basidiome soft and fleshy, hymenophore gelatinous
Cartilosoma
102A.
Subiculum cottony with brown generative hyphae next to the substrate
Anthoporia
103A.
Skeletal hyphae swelling and dissolving in KOH, weakly to distinctly amyloid
Amyloporia
104A.
Resinous matter abundant, present as droplets or globose bodies
Resinoporia
105A.
Rhizomorphs absent, basidiospores allantoid, cylindrical to narrowly ellipsoid
Antrodia
106A.
Basidiospores thin-walled, skeletal hyphae thinner than generative hyphae
Leifiporia
107A.
Basidiomes resupinate with rhizomorphic margin
Fibroporia
107B.
Basidiospores pileate with entire margin
Pseudofibroporia
Key C: Tomentelloid Fungi
Basidiome usually resupinate, hymenophore typically non-poroid, spores hyaline to typically brown or violet in KOH, ornamented, telephoric acid present.
1A.
Basidiome bluish when fresh, greenish when dry, spores violaceous in KOH
Amaurodon
2A.
Hyphae simple-septate, spores echinulate and hyaline in KOH
Tomentellopsis
3A.
Basidiome effused to effused-reflexed, hymenophore irpicoid to lamellate
Lenzitopsis
4A.
Basidia sphaeropedunculate, hyphae mostly simple-septate or clamped with hyaline spores
Pseudotomentella
4B.
Basidia usually clavate, hyphae mostly clamped and spores mostly brownish in KOH
Tomentella (see also Odontia)
Key D
Basidiome usually resupinate, hymenophore non-typically poroid, smooth or hydnoid, with brown asterohyphidia or setae
Key E
Basidiome usually resupinate, hymenophore non-typically poroid, without asterohyphidia; setae absent, dichohyphae and/or dextrinoid binding-skeletal hyphae present
Key F
Basidiome usually resupinate, hymenophore non-typically poroid, without asterohyphidia; setae absent, dichohyphae and/or dextrinoid binding-skeletal hyphae absent; spores amyloid
Key G
Basidiome usually resupinate, hymenophore non-typically poroid, without asterohyphidia; setae absent, dichohyphae and/or dextrinoid binding-skeletal hyphae absent; spores dextrinoid
Key H
Basidiome usually resupinate, hymenophore non-typically poroid, without asterohyphidia; setae absent, dichohyphae and/or dextrinoid binding-skeletal hyphae absent; spores IKI–, basidia with 4-8 sterigmata
Key I
Basidiome usually resupinate, hymenophore non-typically poroid, without asterohyphidia; setae absent, dichohyphae and/or dextrinoid binding-skeletal hyphae absent; spores IKI–, basidia with 2-4 sterigmata, spores thick-walled and smooth, clamps absent or scattered
Key J
Basidiome usually resupinate, hymenophore non-typically poroid, without asterohyphidia; setae absent, dichohyphae and/or dextrinoid binding-skeletal hyphae absent; spores IKI–, basidia with 2-4 sterigmata, spores thick-walled and smooth, clamps usually present (always at the basidial base)
Key K
Basidiome usually resupinate, hymenophore non-typically poroid, without asterohyphidia; setae absent, dichohyphae and/or dextrinoid binding-skeletal hyphae absent; spores IKI–, basidia with 2-4 sterigmata, spores ornamented and/or branched, lobed, triangular or tetrahedral
Key L
Basidiome usually resupinate, hymenophore non-typically poroid, without asterohyphidia; setae absent, dichohyphae and/or dextrinoid binding-skeletal hyphae absent; spores IKI–, basidia with 2-4 sterigmata, spores smooth, lyocystidia present
Key M
Basidiome usually resupinate, hymenophore non-typically poroid, without asterohyphidia; setae absent, dichohyphae and/or dextrinoid binding-skeletal hyphae absent; spores IKI–, basidia with 2-4 sterigmata, spores smooth, lyocystidia absent, generative hyphae with simple septa, cystidial organs present
Key N
Basidiome usually resupinate, hymenophore non-typically poroid, without asterohyphidia; setae absent, dichohyphae and/or dextrinoid binding-skeletal hyphae absent; spores IKI–, basidia with 2-4 sterigmata, spores smooth, lyocystidia absent, generative hyphae with simple septa, cystidial organs absent (hyphidia may be present)
Key O
Basidiome usually resupinate, hymenophore non-typically poroid, without asterohyphidia; setae absent, dichohyphae and/or dextrinoid binding-skeletal hyphae absent; spores IKI–, basidia with 2-4 sterigmata, spores smooth, lyocystidia absent, generative hyphae with clamps, hyphal system di- or trimitic
Key P
Basidiome usually resupinate, hymenophore non-typically poroid, without asterohyphidia; setae absent, dichohyphae and/or dextrinoid binding-skeletal hyphae absent; spores IKI–, basidia with 2-4 sterigmata, spores smooth, lyocystidia absent, generative hyphae with clamps, hyphal system monomitic, dendrohyphidia present
Key Q: Cystidia Present
Basidiome usually resupinate, hymenophore typically non-poroid, asterohyphidia and setae absent, dichohyphae and dextrinoid binding-skeletal hyphae absent, spores IKI–, basidia with 2–4 sterigmata, spores smooth, lyocystidia absent, generative hyphae with clamps, hyphal system monomitic, dendrohyphidia absent, cystidia present.
1A.
Hyphae and cystidia amyloid
Amylohyphus
3A.
Cystidia with an apical umbrella-like encrustation, spores thin-walled
Dextrinocystis
3B.
Cystidia lightly encrusted, not with an apically cap, spores slightly thick-walled
Hemmesomyces
4A.
Subicular hyphae with projections covered with a double cap encrustation
Sceptrulum
7A.
Basidiome reddish, strongly pilose by the thick-walled protruding cystidia, wood discoloured reddish by the fungus
Erythromyces
8A.
Basidiome cupulate, gregarious
Campylomyces
8B.
Basidiome resupinate to effused-reflexed
Duportella
10A.
Basidiome decorticant, gloeocystidia present
Peniophora
10B.
Basidiome not decorticant, gloeocystidia absent
Phlebia (see also Cabalodontia)
11A.
Basidiome semigelatinous, hyphae gelatinized and difficult to discern
Phlebia
12A.
Hymenophore with rounded tubercles
Scopulodontia
13A.
Basidiome pink, orange, reddish, dark bluish or violaceous
Peniophora
15A.
Cystidia cylindrical to subulate, encrusted only at the basal part, apically naked, basidia mostly pleural
Lepidomyces
17A.
Gloeocystidia SA+ present, leptocystidia absent
Metulodontia
17B.
Gloeocystidia SA+ absent, leptocystidia cylindrical to capitate present
Xylodon (=Palifer)
18A.
Spores up to 6 μm long, basal hyphae 4–8 μm wide
Ceraceomyces
19A.
Basidia clavate to subcylindrical, echinulate cells usually present
Peniophorella
19B.
Basidia suburniform, echinulate cells absent
Hyphoderma
21A.
Spores 12–18 μm long, fusiform to narrowly fusiform
Suillosporium
22A.
Repetobasidia present
Repetobasidium
23A.
With lagenocystidia
Hyphodontia
24A.
Septocystidia hyphoid, very finely encrusted with thin crystals
Amphinema
26A.
Basidiome ceraceous, cystidia with several septa, more or less encrusted
Hyphoderma
26B.
Basidiome pellicular, cystidia with one clamped septum, smooth
Atheloderma
27A.
Cystidia and basidia thin-walled, cystidia rare
Ceraceomyces
28A.
Cystidia smooth faintly cyanophilous
Tubulicrinopsis
28B.
Cystidia smooth or some encrusted as lamprocystidia, acyanophilous
Amauromyces
30A.
Clamps few and scattered in some hyphae but absent in the basidial base
Climacodon
31A.
Oleiferous hyphae present
Stecchericium
31B.
Oleiferous hyphae absent
Mycoleptodonoides
32A.
Basidiome resupinate to effused-reflexed, hymenophore smooth, violaceous
Chondrostereum
34A.
Spores on average less than 7 μm long
Kneiffiella
36A.
Cystidia 8–12 μm wide, with a drop of secretion at the subcapitate apex
Dacryobolus
36B.
Cystidia 5–6 μm wide, without drop of secretion at the apex
Kneiffiella
37A.
Cystidia 150–300 μm long, basidia 50–100 μm long
Chaetoderma
37B.
Cystidia up to 100–130 μm long, basidia up to 20–50 μm long
Crustoderma
38A.
Hymenophore distinctly poroid
Kneiffiella (=Chaetoporellus)
40A.
Sterigmata large, separated from the rest of the basidium by a simple septum, spores repetitive
Tulasnella
41A.
Hymenophore reddish in KOH
Crustodontia
41B.
Hymenophore with no colour changes in KOH
Phlebia
43A.
Asterocystidia present
Resinicium
43B.
Asterocystidia absent
Skvortzovia (check also Resinicium s.l.)
45A.
Rosette-like crystals present, cystidiols capitulate, spores allantoid
Sidera
46A.
Cystidia excreting a drop of sticky liquid, spores allantoid
Dacryobolus
47A.
Spores 8–12 μm long
Basidioradulum
48A.
With subulate leptocystidia and gloeocystidia, spores 3–4 μm long
Physodontia
50A.
Gloeocystidia with yellowish contents, brownish in sulphovanillin
Hyphodontiastra
50B.
Gloeocystidia encrusted with yellowish resinous matter, negative in sulphovanillin
Parvodontia
51A.
With thin-walled tubular cystidia, spores allantoid
Kneiffiella (=Alutaceodontia)
52A.
Basidiome yellowish to brown or orange, hyphae usually coloured
Pseudolagarobasidium
53A.
With large, distinct, and projecting capitate leptocystidia
Kneiffiella (=Deviodontia)
53B.
Cystidia or cystidioles not distinct, as capitate hyphal ends (torulose cystidia or gloeocystidia may be present but rare or inconspicuous)
Xylodon
55A.
Acanthophyses (and acanthobasidia) present, basidia with one long sterigma
Heteroacanthella
55B.
Acanthophyses absent, basidia usually with 2–4 sterigmata
Oliveonia
56A.
Basidiome thin and inconspicuous, basidia subglobose to obconical
Sphaerobasidium
57A.
Cystidia with an apical papilla or a cap of yellow to reddish-brown incrustations
Coronicium
58A.
Basidiome pellicular, capitate cystidia present
Lyoathelia
60A.
Basidia suburniform
Hyphoderma
61A.
Spores dacryoid (tear- or pear-shaped) to obliquely ellipsoid, often in groups of 2–4
Cylindrobasidium
62A.
Spores 6.5–8 μm wide, echinulate cells absent
Clavulicium
62B.
Spores up to 5 μm wide, echinulate cells usually present
Peniophorella
64A.
Basidia urniform, cystidia present as flexuose gloeocystidia
Sistotrema
65A.
Cystidia 6–13 μm wide and often longer than 100 μm
Hyphoderma
66A.
With two kinds of cystidia:1) moniliform and 2) subulate or capitate
Hastodontia
67A.
Capitate or subulate, more or less encrusted cystidia present
Lyomyces
67B.
Cystidia, if present, different, not distinct, as hyphoid cystidiols
Xylodon
68A.
Basidia with a basal clamp, subicular hyphae with simple-septa
Hyphodontiella
69A.
Basidia 8–12 μm long, with clavate to flexuous gloeocystidia
Parvobasidium
70A.
Hymenophore becoming violaceous in KOH
Ceraceomyces
71B.
Spores up to 3 μm wide
Amphinema
Key R: Cystidia Absent
Basidiome usually resupinate, hymenophore typically non-poroid, asterohyphidia and setae absent, dichohyphae and dextrinoid binding-skeletal hyphae absent, spores IKI–, basidia with 2–4 sterigmata, spores smooth, lyocystidia absent, generative hyphae with clamps, hyphal system monomitic, dendrohyphidia absent, cystidia absent.
2A.
Hyphal system dimitic/pseudodimitic, hymenophore smooth to folded
Auriculariopsis
2B.
Hyphal system monomitic, hymenophore hydnoid by protruding hyphal fascicles
Mycothele
3A.
Basidiome gregarious formed by minute globules
Mycostigma
6A.
Basidiome tubaeform with a hollow stipe
Parastereopsis
7A.
Skeletal hyphae absent, hyphae non-inflated
Stereopsis
7B.
Skeletal hyphae present in the stipe, contextual hyphae inflated
Inflatostereum
8A.
Basidiome with well-developed pilei, hymenophore merulioid
Phlebia (=Merulius)
8B.
Basidiome stipitate-pileate, hymenophore aculeate
Mycorrhaphium
9A.
Sterigmata large, separated from the rest of the basidium by a simple septum, spores repetitive
Tulasnella
10A.
Basidiome pinkish, pathogens on grasses
Limonomyces
12A.
Hymenophore poroid, basidia urniform
Sistotrema
14A.
Basidiome subgelatinous to ceraceous, hyphae embedded in a gelatinous matrix, clamps and hyphae difficult to discern
Phlebia sensu lato
15A.
Hymenophore smooth to slightly merulioid, spores subglobose to ellipsoid
Ceraceomyces
15B.
Hymenophore distinctly merulioid, spores narrowly cylindrical to fusiform
Serpulomyces
17A.
Spores 8–10 μm long
Hydnocristella
19A.
Spores usually longer than 10 μm, basidia large, normally longer than 50 μm
Epithele
19B.
Spores smaller, up to 10 μm, basidia about 10–15 μm long
Pteridomyces
20A.
Hyphal system pseudodimitic, with skeletoid or pseudoskeletal hyphae
Fibrodontia
21A.
Basidia suburniform (cystidiols often present!)
Xylodon
23A.
Subicular hyphae hyaline, refractive in KOH
Odontiopsis
23B.
Subicular hyphae brownish, non-refractive in KOH
(see also Crepatura) Pirex
25A.
Spores ellipsoid to globose or more or less rhomboid
Brevicellicium
25B.
Spores reniform to allantoid
Brevicellopsis
27A.
Hymenophore raduloid, spores ellipsoid to globose 8–12 μm long
Radulomyces
28A.
Spores ellipsoid
Amaurohydnum
28B.
Spores pyriform
Radulodontia
29A.
Basidia terminal, spores ellipsoid to allantoid
Phlebia (=Mycoacia)
29B.
Basidia pleural, spores globose
Aphanobasidium
31A.
Basidia clavate to ovoid, spores citriform, if subglobose to ellipsoid then 2–4 μm wide
Oliveonia
31B.
Basidia obconical, spores subglobose to ovoid 3.5–6 μm wide
Scotomyces
33A.
Basidia 30–50 μm long, with a lateral hook-like hypha
Uncobasidium
33B.
Basidia shorter, without such a lateral hook-like hypha
Aphanobasidium
34A.
Basidia urniform, hyphae characteristically with oily contents
Sistotrema
35B.
Hyphae in subiculum and cords different (ampullaceous swellings may occur in more or less isodiametric hyphae in subhymenium)
36
37A.
Spores 8–10 μm long
Conohypha
37B.
Spores up to 6 μm long
Brevicellicium
38A.
Hyphae alternating clamps and simple septa
Hyphodontiella
39A.
Spores yellowish to ochraceous coloured
Cerocorticium (=Chrysoderma)
40A.
Basidiome ceraceous, hyphae gelatinized and difficult to discern
Phlebia
42A.
Basidia with two long sterigmata, spores allantoid
Cerinomyces
43A.
Basidiome brown to dark brown, subhymenial hyphae encrusted with resinous matter by age, spores navicular
Luellia
44A.
Hymenial surface white, changing to purple in KOH
Purpureocorticium
47A.
Basidiome thin, almost invisible, watery gray
Galzinia
48A.
Basidia on average longer than 30 μm, spore usually longer than 7 μm
Hyphoderma
48B.
Basidia on average shorter than 30 μm, spore usually up to 7 μm long
Xylodon
50A.
Basidia up to 20 μm long, tetrasporic
Athelopsis
51A.
Basidia 50–75 μm long, spores globose to subglobose, 9–13 μm in diameter
Globulicium
52A.
Basidia bisporic, 20–25 μm long, spores wider than 5 μm
Athelicium
52B.
Basidia with 2–3–4 sterigmata, 27–30 μm long, spores up to 4 μm wide
Thujacorticium
53A.
Basal hyphae cinnamon encrusted, violaceous in KOH
Ceraceomyces
54A.
Basidia distinctly very thick-walled
Tubulicrinopsis
56B.
Spores on average less than 2.5 μm wide
Leptosporomyces
57A.
Spores up to 4.5 μm wide, thin-walled, on bark of living trees
Dendrothele
58A.
Spores cylindrical to ellipsoid, more than 15 μm long
Cerocorticium
58B.
Spores usually ellipsoid, up to 15 μm long
Radulomyces