North American species of Mycena.

EUMYCENA: TYPICAE

229

CARTILAGINOUS OR FRAGIL LIGNICOLOUS SPECIES
33. Cheilocystidia fusoid-ventricose type; if branched, see no. 43 (apex
echinulate in M. borealis).................................... 34
33. Cheilocystidia clavate-roughened or, if fusoid-ventricose, sometimes
giving rise to two or more fingerlike prolongations, sometimes
merely irregular in outline (see M. semivestipes, M. laevigata, and
M. ochraceicinerea, which may have typically fusoid cystidia but
are keyed out here)........................................ 43
34. Pleurocystidia very conspicuous............................... 35
34. Pleurocystidia rare to absent and not projecting much if present.... 41
35. Odor nitrous................................................ 36
35. Odor none................................................... 37
36. Stipe smooth, color remaining dark; pleurocystidia 60-90 A long
152. M. macrocystidia
36. Stipe fibrillose-striate at least when young, white, pileus pale in age;
cystidia 60-110 u long......................... 151. M. niveipes
36. Stipe smooth; pileus dark; pleurocystidia up to 50-54 At long
153. M. alcalina
37. Pleurocystidia with echinulate apices............... 147. M. borealis
37. Pleurocystidia smooth......................................... 38
38. Stipe soon smooth and polished................................ 39
38. Stipe fibrillose to somewhat striate, at least when young........... 40
39. Gills broadly and deeply adnexed; pellicle gelatinous in KOH
148. M. excisa
39. Gills hooked or ascending-adnate (see also M. floccipes and M. Kauffmaniana).................................... 153. M. alcalina
40. Cespitose; pileus blackish to dull sordid brown and scarcely fading;
gills close to crowded........................ 150. M. algeriensis
40. Solitary to gregarious; gills subdistant; pileus dark; with appearance
of Collybia.................................. 149. M. tenuiceps
40. Pileus fuscous on disc, whitish toward margin, fading to whitish;
stipe very soon almost snow white............. 151. M. niveipes
41. Pileus grayish, sometimes fading to white........................ 42
41. Pileus whitish; gills pale incarnate (see also M. laevigata)
154. M. incarnatifolia
42. Spores globose, 3.5-4 ua, nonamyloid............... 191. M. ulmicola
42. Spores broadly ellipsoid to subglobose, 5-6 (7) X 4-5 U
155. M. collybiiformis
42. Spores ellipsoid, larger than above; cheilocystidia smooth, 23-30 X
5-7 ju; carpophore similar to M. inclinata in appearance
159. M. pseudoinclinata