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

1A. Basidiome pseudostipitate to stipitate and pileate Key A
1B. Basidiome sessile and resupinate to slightly pileate 2
2A. Hymenophore poroid, with lacerate pores or with anastomosing ridges Key B
2B. Hymenophore diverse, not typically poroid 3
3A. Spores hyaline to typically brown or violet in KOH, ornamented, telephoric acid present Key C
3B. Not with the above combination 4
4A. Brown star-shaped asterohyphidia or setae present Key D
4B. Asterohyphidia or setae absent 5
5A. Dichohyphae and/or binding-skeletal hyphae dextrinoid Key E
5B. Not as above 6
6A. Spores with a reaction in Melzer's reagent (amyloid or dextrinoid) 7
6B. Spores without a reaction in Melzer's reagent 8
7A. Spores amyloid Key F
7B. Spores dextrinoid Key G
8A. Basidia mostly with (1-3)4 sterigmata (if number of sterigmata not known follow this step) 9
8B. Basidia mostly with more than 4 sterigmata Key H
9A. Spores distinctly thick-walled and smooth 10
9B. Spores thin-walled and/or ornamented and/or branched, lobed, triangular or tetrahedral 11
10A. Clamps either totally absent or scattered Key I
10B. Clamps present on nearly all septa (always at the basidial base) Key J
11A. Spores ornamented and/or branched, lobed or tetrahedral (easily seen in Melzer!) Key K
11B. Spores smooth 12
12A. Lyocystidia present Key L
12B. Lyocystidia absent 13
13A. Generative hyphae with simple septa or occasional clamps 14
13B. Generative hyphae with clamps 15
14A. Cystidial organs present (excepting hyphidia or dendrohyphidia) Key M
14B. Cystidial organs absent Key N
15A. Hyphal system dimitic/trimitic Key O
15B. Hyphal system monomitic (or pseudodimitic) 16
16A. Dendrohyphidia or dendrophyses present Key P
16B. Dendrohyphidia or dendrophyses absent (paraphysoid hyphae may be present) 17
17A. Cystidial organs present Key Q
17B. Cystidial organs absent Key R

Key A

Basidiome pseudostipitate to stipitate and pileate.

Key B

Basidiome usually sessile and resupinate to pileate, hymenophore poroid with lacerate pores or with anastomosing ridges.

Key C

Basidiome usually resupinate, hymenophore non-typically poroid, spores hyaline to typically brown or violet in KOH, ornamented, telephoric acid present (tomentelloid fungi).

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

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 absent, cystidia present.

Key R

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 absent, cystidia absent.

References

  1. Gorjón SP. 2020. Genera of corticioid fungi: keys, nomenclature and taxonomy. Studies in Fungi 5:125–309. PDF Link