North American species of Mycena.

402 NORTH AMERICAN SPECIES OF MYCENA
5. Pileus dark gray to blackish on disc, pale gray in age; cheilocystidia
clavate-echinulate...................0......2. 0. M. clavicularis
5. Pileus sordid milk white or cream-colored, disc darker than margin;
cheilocystidia with thornlike projections (not echinulate)
204. M. insignis
CAESPITOSAE
6. Spores small, not over 6 u long................................. 7
6. Spores over 6 u long (6-7, in M. lilacifolia)..................... 10
7. Pileus tinged with orange or yellow and gills bordered pale yellow
or orange..................................... 209. M. texensis
7. Pileus not with orange or yellow............................... 8
8. Pileus plicate-striate; cheilocystidia without pedicels
212. M. subepipterygia
8. Pileus not plicate; cheilocystidia with long contorted pedicels....... 9
9. Pileus gray; gills somewhat decurrent and broadest at stipe; pleurocystidia abundant............................ 208. M. euspeirea
9. Pileus gray; gills adnate, broadest in middle; pleurocystidia rare
207. M. hondurensis
10. Fruiting body brilliant yellow to orange........................ 11
10. Fruiting body white to grayish................................ 12
11. Gills yellow, margined with orange................ 210. M. Leaiana
11. Gills lilac or pallid............................. 211. M. lilacifolia
12. Pileus gray, fading to white................... 156. M. laevigata
12. Pileus white, gregarious to subcespitose; northern United States
206. M. Austini
12. Pileus white, cespitose; southern United States.... 205. M. glutinosa
VISCOSAE
13. Cheilocystidia with one or more prominent thornlike projections;
often quite irregular in shape................ 213. M. griseoviridis
13. Cheilocystidia mostly aciculate.. 214. M. griseoviridis var. cascadensis
13. Cheilocystidia merely roughened with fingerlike prolongations or
rodlike projections......................................... 14
14. Taste mild or farinaceous.................................... 16
14. Taste strongly rancid-farinaceous, very disagreeable............... 15
15. Odor subfarinaceous, disagreeable.................. 215. M. viscosa
15. Odor of iodoform.................. 216. M. viscosa var. iodiolens
16. Usually growing on mossy conifer logs or stumps or on debris of conifers........................... 219. M. epipterygia var. lignicola
16. On humus and carpets of conifer needles......................... 17