North American species of Mycena.

SUBGENUS EUMYCENA
IN EUMYCENA, the largest of the four subgenera, are grouped all
the species with smooth spores and nonviscid more or less equal
stipes. The diversity of forms included is indicated by the number of
sections into which the subgenus is divided. As is to be expected,
many evolutionary trends are evident; some are represented by large
numbers of species, and others are quite fragmentary. As has been
previously stated, the limits between this subgenus and Omphalia
are not sharp so far as the white and gray species are concerned.
The section Typicae represents the center of the genus around which
the other eleven sections and three subgenera are arranged.
KEY TO SECTIONS
1. Stipe with milklike or brightly colored latex.............. Lactipedes
1. Stipe with copious watery juice, in some staining the fruiting body
blackish............................................ H ydropus
1. Stipe with merely scant watery juice, not staining black or blackish w hen bruised............................................ 2
2. Densely gregarious on naked bark of standing trees or fallen trunks,
occasionally on bark of branches; mostly small species with base
of stipe naked or nearly so........................... Corticolae
2. N ot as above.................................................. 3
3. Carpophore usually with bright to sordid-blue or greenish-blue colors,
at least at base of stipe; stipe densely pubescent; pileus with thick
gelatinous pellicle................................. Cyanescentes
3. N ot as above.................................................. 4
4. Pileus minute, 1-6 (10) mm. broad; stipe usually about 0.5 mm. thick,
filiform........................................... D em inutivae
4. Pileus larger (1-5 cm.); stipe 1 mm. i thick or occasionally down to
0.5 mm. in depauperate forms................................. 5
5. Gills not marginate; carpophore white or brightly colored (red, orange,
yellow, etc.).......................................... A donidae
5. Gills marginate; carpophore brightly colored or colors mixed with
fuscous and, consequently, dull (see M. Kauffmanii and M. marginella also)......................................... Calodontes
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