A key to 23 accepted species of Kneiffiella
1a. Hymenophore smooth.................................................................................................................................................................	2
b. Hymenophore tuberculate, grandinioid, odontioid, coralloid, irpicoid or poroid..............................................................	10
2a. Basidia with two, rarely three sterigmata..................................................................................................................	K. efibulata
b. Basidia with four sterigmata.........................................................................................................................................................	3
3a. Without clamp connections.........................................................................................................................................................	4
b. With clamp connections.................................................................................................................................................................	5
4a. Hymenophore cream; basidiospores less than 5 µm long, less than 2.5 µm wide..............................................	K. tetraspora
b. Hymenophore whitish to ochraceous or slightly ochre-brown; basidiospores more than 5 µm long, more than 2.5 µm wide..........................................................................................................................................................................	K. crassispora
5a. Basidiospores less than 6 μm long..............................................................................................................................................	6
b. Basidiospores more than 6 μm long.............................................................................................................................................	8
6a. Basidiospores cylindrical to allantoid; tramacystidia without exudate....................................................................	K. altaica
b. Basidiospores ellipsoid or cylindrical to suballantoid; tramacystidia sometimes apically with exudate........................	7
7a. Basidiospores less than 3 μm wide.......................................................................................................................	K. microspora
b. Basidiospores more than 3 μm wide............................................................................................................................	K. alienata
8a. Basidiospores less than 2.5 μm wide...................................................................................................................	K. subalutacea
b. Basidiospores more than 2.5 μm wide........................................................................................................................................	9
9a. Hymenophore white to slightly cream; tramacystidia without crystals............................................................	K. cineracea
b. Hymenophore creamish white to slightly yellow, light ochre in spots; tramacystidia smooth or encrusted, sometimes with simple secondary septa............................................................................................................	K. decorticans
10a. Without clamp connections....................................................................................................................................................	11
b. With clamp connections..............................................................................................................................................................	16
11a. Basidiospores less than 5 μm long.........................................................................................................................................	12
b. Basidiospores more than 5 μm long..........................................................................................................................................	15
12a. Hymenophore odontioid or irpicoid.....................................................................................................................................	13
b. Hymenophore slightly grandinioid or tuberculate to grandinioid......................................................................................	14
13a. Hymenophore odontioid, fresh cream-colored, dry buff or dark brown; basidiospores less than 4 μm long.........................................................................................................................................................................	K. subefibulata
b. Hymenophore odontioid to irpicoid, white; basidiospores more than 4 μm long..........................................	K. subglobosa
14a. Hymenophore tuberculate to grandinioid, yellowish brown to ochraceous; cystidia without exudate; basidiospores more than 2.5 μm wide..................................................................................................................	K. byssoidea
b. Hymenophore slightly grandinioid, cream; cystidia with exudate; basidiospores less than 2.5 μm wide...	K. tetraspora
15a. Basidia with two or rarely three sterigmata; basidiospores cylindrical to slightly allantoid.........................	K. efibulata
b. Basidia with four sterigmata; basidiospores ellipsoid.........................................................................................	K. crassispora
16a. Capitate cystidia in subiculum present.................................................................................................................................	17
b. Capitate cystidia in subiculum absent......................................................................................................................................	18
17a. Basidiospores broadly ellipsoid (Q < 1.5), thin- to slightly thick-walled….......................................................	K. sinensis
b. Basidiospores ellipsoid (Q > 1.5), thin-walled..................................................................................................	K. pilaecystidiata
18a. Tramacystidia thin-walled......................................................................................................................................................	19
b. Tramacystidia thick-walled........................................................................................................................................................	22
19a. Hymenophore irpicoid to poroid, white to yellowish; spores narrowly allantoid, spores 3–4 × 0.5–1 μm.....	K. abdita
b. Hymenophore grandinioid to odontioid..................................................................................................................................	20
20a. Basidiospores narrowly allantoid or semicircle-like, no more than 2 µm wide.............................................................	21
b. Basidiospores broadly ellipsoid to ovoid, more than 2 µm wide...................................................................	K. eucalypticola
21a. Basidiospores narrowly allantoid, more than 5 µm long; aculei sometimes grouped together then coralloid.......................................................................................................................................................................	K. alutacea
b. Basidiospores semicircle-like, no more than 5 µm long; aculei not grouped....................................................	K. curvispora
22a. Septa of basal hyphae and part of subiculum without clamp connections; short aculei (up to 50 μm) among long aculei (up to 800 μm)...............................................................................................................................................	K. stereicola
b. Clamp connections everywhere; aculei uniform.....................................................................................................................	23
23a. Basidiospores less than 4 μm wide........................................................................................................................................	24
b. Basidiospores more than 4 μm wide.........................................................................................................................................	27
24a. Basidiospores less than 5.5 μm long.................................................................................................................	K. tubuliformis
b. Basidiospores more than 6 μm long..........................................................................................................................................	25
25a. Basidiospores cylindrical to suballantoid, more than 2.5 μm wide...............................................................	K. decorticans
b. Basidiospores long allantoid, less than 2.5 μm wide..............................................................................................................	26
26a. Hymenophore odontioid...........................................................................................................................................	K. floccosa
b. Hymenophore slightly grandinioid.......................................................................................................................	K. subalutacea
27a. Basidiospores cylindrical; hymenophore cream to ochraceous, aculei up to 1 mm long..............................	K. abieticola
b. Basidiospores ellipsoid; hymenophore cream, aculei up to 3 mm long............................................................	K. barba-jovis