North American species of Mycena.

SUBGENUS PSEUDOMYCENA
N THIS subgenus are grouped all the minute, delicate species
characterized by the presence of a small but distinct bulb or disc
at the base of the stipe and having the stipe readily separable from
the pileus. In one section the fruiting bodies are very coarsely granular (as seen under a lens) owing to the covering of verrucose globular
cells. The two sections together represent a remarkably homogeneous group of species. The limits of the subgenus, as given here,
exclude such species as M. pterigena and M. corticola and, in fact,
are very closely in line with the limits of the section Basipedes of
Fries. M. Brownii, with a very distinct bulb but with the stipe not
separable from the pileus, is placed in the Omphaliariae of Eumycena.
KEY TO SECTIONS
Verrucose inflated cells covering pileus, fruiting bodies generally with
chalky appearance............................ Section Tenerrimae
Pileus setulose, glabrous, or slightly pruinose at first, or soon becoming
glabrous and moist........................... Section Basipedes
TENERRIMAE
1. Cheilocystidia with apical needlelike projections...... 1. M. tenerrima
1. Cheilocystidia merely verrucose.................. 2. M. osmundicola
BASIPEDES
1. Pileus and stipe at first covered with long, thick-walled hyaline setae
8. M. longiseta
1. Pileus and stipe not having thick-walled setae..................... 2
2. Pileus yellowish, bulb bright yellow.................. 4. M. Gaultheri
2. Not as above.................................................. 3
3. Cheilocystidia 18-25 X 7-12,u, ovoid to clavate, apices echinulate
3. M. Mucor
3. Cheilocystidia, if rough, with fingerlike projections, their outlines often
irregular; sometimes smooth and fusoid-ventricose............... 4
4. Spores globose to subglobose....................... 7. M. clavularis
4. Spores ellipsoid............................................ 5
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