1	Cystidia absent	2
–	Cystidia present	5
2	Hymenial surface grandinioid	H. acystidiatum
–	Hymenial surface smooth	3
3	Basidiospores > 10.5 µm in length	H. densum
–	Basidiospores < 10.5 µm in length	4
4	Hymenophore cracked; basidiospores > 8.5 µm in length	H. fissuratum
–	Hymenophore uncracked; basidiospores < 8.5 µm in length	H. sibiricum
5	Hymenophore smooth	6
–	Hymenophore tuberculate, porulose, grandinioid or odontoid	15
6	Two types of cystidia present	7
–	One type of cystidia present	8
7	Moniliform cystidia absent	H. microcystidium
–	Moniliform cystidia present	H. sinense
8	Hymenophore uncracked	9
–	Hymenophore cracked	11
9	Basidiospores > 11 µm in length	H. definitum
–	Basidiospores < 11 µm in length	10
10	Basidiospores > 8.5 µm in length	H. microporoides
–	Basidiospores < 8.5 µm in length	H. puerense
11	Cystidia moniliform	12
–	Cystidia cylindrical	13
12	Basidiospores > 9 µm in length	H. litschaueri
–	Basidiospores < 9 µm in length	H. moniliforme
13	Basidiospores ellipsoid < 10 μm in length	H. rimulosum
–	Basidiospores cylindrical > 10 μm in length	14
14	Basidiospores > 12 µm in length	H. cremeum
–	Basidiospores < 12 µm in length	H. subclavatum
15	Hymenophore odontoid or grandinioid	16
–	Hymenophore tuberculate, porulose	19
16	Hymenophore odontoid	17
–	Hymenophore grandinioid	18
17	Basidiospores < 4.5 µm in width	H. transiens
–	Basidiospores > 4.5 µm in width	H. formosanum
18	Basidiospores larger 7–10.5 × 3–4.5 µm	H. tenuissimum
–	Basidiospores smaller 6–8 × 2.8–3.2 μm	H. subsetigerum
19	Cystidia of two types	20
–	Cystidia of one type	23
20	Septate cystidia absent	21
–	Septate cystidia present	22
21	Basidiospores < 4 µm in width	H. variolosum
–	Basidiospores > 4 µm in width	H. crystallinum
22	Basidia 2-sterigmata, basidiospores > 13 µm in length	H. pinicola
–	Basidia 4-sterigmata, basidiospores < 13 µm in length	H. floccosum
23	Septate cystidia present	24
–	Septate cystidia absent	25
24	Hymenophore porulose to pilose, basidia < 5 µm in width	H. mopanshanense
–	Hymenophore tuberculate, basidia > 5 µm in width	H. setigerum
25	Hymenophore porulose	H. obtusiforme
–	Hymenophore tuberculate, colliculose	26
26	Cystidia < 30 µm in length	H. cremeoalbum
–	Cystidia > 30 µm in length	27
27	Basidia > 30 µm in length	28
–	Basidia < 30 µm in length	29
28	Hymenophore cracking, cystidia < 10 µm in width	H. medioburiense
–	Hymenophore not cracking, cystidia > 10 µm in width	H. clavatum
29	Hymenophore colliculose	H. nemorale
–	Hymenophore tuberculate	H. membranaceum