North American species of Mycena.

226 NORTH AMERICAN SPECIES OF MYCENA

1. Cartilaginous-pliant species: usually on decaying wood and often
cespitose (if on humus, cespitose, or not fragile; if fragile, then lignicolous). The large cartilaginous whitish or very pale species often
cespitose on wood are keyed out here rather than in the Adonidae.. 33
2. Cheilocystidia roughened (at least over ventricose portion if they
are fusoid-ventricose), with rodlike projections or numerous contorted fingerlike projections or merely verrucose............... 3
2. Cheilocystidia, if present, smooth, fusoid-ventricose, or with two to
four or, occasionally, more obtuse prolongations................ 16
FRAGILE SPECIES WITH ROUGH CHEILOCYSTIDIA
3. Pleurocystidia fusoid-ventricose, 54-90 X 8-12 u; ventricose portion
often roughened............................... 124. M. latifolia
3. Pleurocystidia, if present, clavate and with roughened apices....... 4
4. Pellicle gelatinous to subgelatinous or broad gelatinous layer present
just beneath pellicle......................................... 5
4. No gelatinous layers present in pileus............................ 6
5. Odor alkaline or lacking; subpellicular layer gelatinous
125. M. constans
5. Pellicle gelatinous....................M. pseudoclavicularis (p. 374)
5. Odor none; pellicle subgelatinous, thickish....................... 5a
(a) Stipe breaking readily at base when collected; pileus usually
plicate-striate to scalloped................. 133. M. plicosa
(a) Stipe not as above; pileus slightly sulcate only in age
126. M. pusilla
6. Pileus russet, tawny, or vinaceous fawn tinged with gray at times... 7
6. Pileus dominantly gray, fuscous, bluish gray, or grayish brown.... 8
7. Fruiting body Galerina-like (russet to tawny); pleurocystidia absent
129. M. psammicola
7. Fruiting body vinaceous fawn when fresh, fading to ashy or avellaneous in age; pleurocystidia present............... 130. M. metata
8. Stipe long in relation to width of cap (cap 5-25 mm., stipe 6-12 cm.).. 9
8. Stipe shorter in relation to width of cap (cap 1-4 cm., stipe 3-8 cm.)..11
9. A strong odor of iodoform developing after fruiting bodies have been
gathered..................................... 137. M. iodiolens
9. Odor not distinctive........................................... 10
10. Growing in sphagnum, hence long stipe......... 135. M. atroalboides
10. Growing in open on humus or needle beds or on moss.. 136. M. filopes
11. Pileus typically large (2-3.5-5 cm.)............................ 12
11. Pileus 5-10 (20) m m........................................... 13