1a.  Hyphae clamps present

2

1b.  Hyphae clamps absent

3

2a.  Spores 6-7,5 µm

P. humicola

2b.  Spores 9-11 µm and chlamydospores on rhizomorphs present

P. vepallidospora

3a.  Spores brownish, subicular hyphae brown, thick-walled (P. tristis-complex)

4

3b.  Spores hyaline to yellowish, subicular hyphae hyaline to pale brownish

8

4a.   all subicular hyphae < 4,5 µm

5

4b.   most subicular hyphae > 4,5 µm

7

5a.   Rhizomorphes dimitic

P. atrofusca

5b.   Rhizomorphes monomitic

6

6a.   Spores Ø 7-8 µm, hymenium weakly cyanescent

P. rotundispora

6b.   Spores Ø 8-10 µm, hymenium strong cyanescent

P. media

7a.   Spores Ø < 8 µm

P. sciastra

7b.   Spores Ø > 8 µm

13

8a.   Brown chlamydospores present on rhizomorphs

P. rhizopunctata

8b.   Chlamydosporen absent

9

9a.   Two types of spores present, 5,5-7 and 8-11 µm, hymenophore paler than the almost blackish subiculum

P. nigra

9b.   only one type of spores present, subiculum greyish to pale brown

10

10a. Hymenium strong cyanescent, basidia up to 100 µm long, Hymenophor greenish-bluish

P. flavovirens

10b. Hymenium not or weakly cyanescent

11

11a. Hymenophore lightgrey, subiculum darker than the fertile area

12

11b. Hymenophore brownish, subiculum concolorous to paler than the fertile area, margin mostly white

P. mucidula

12a. Spores not lobed, spines long with forked apex

P. molybdaea

12b. Spores lobed with broad verrucae not or only shortly and bluntly echinulate

P. griseopergamacae

13a. Hymenium cyanescent

14

13b. Hymenium not cyanescent

P. umbrina

14a. Spores Ø 9-10,5 µm

P. pluriloba

14b. Spores Ø 8-9 µm 

P. tristis