North American species of Mycena.

202 NORTH AMERICAN SPECIES OF MYCENA

Pileus 1-3.5 cm. broad, convex to obtusely conic, becoming broadly
campanulate or developing a low obtuse umbo in age, surface moist,
at first densely white-pruinose, soon polished, subhygrophanous,
"dark olive" (blackish olive) when fresh, the margin "light chalcedony yellow" (pale clear yellow), fading to sordid olive gray with a
whitish margin before losing moisture, pale "avellaneous" to pale
olive gray when faded, striate to the disc when moist, margin entire;
flesh watery gray, fragile, odor and taste not distinctive; lamellae
narrow, moderately close, becoming subdistant, ascending-adnate,
dull pale olive gray, margin "pale green yellow," usually staining
sordid purplish brown in age; stipe 4-12 (15) cm. long, 1.5-3 mm.
thick, tubular, fragile, equal or base a bit enlarged and strigose with
"pale green-yellow" hairs, faintly pruinose above, polished in age,
pale or dark olive gray with a decided yellowish tinge, apex pale yellow
at times, in age often staining dull reddish brown from, the base
upward.
Spores 7.5-9 X 4-5 y, ellipsoid, smooth, amyloid; basidia fourspored; pleurocystidia and cheilocystidia similar, 28-33 X 7-10,,
abundant to scattered, clavate to subeapitate, the enlarged portion
echinulate, contents pale yellow to nearly hyaline; gill trama homogeneous, pale vinaceous brown in iodine; pileus trama with a thin
pellicle, a differentiated hypoderm, and a tramal body of filamentous
but moderately broad cells, all parts below the pellicle vinaceous
brown in iodine.
Habit, habitat, and distribution.-Gregarious to scattered under
conifers, Thuja plicata in particular; Michigan, Washington, Oregon,
and California. It appears to be very abundant in Oregon.
Material studied. Smith, 977, 3453, 3508, 3546, 3714, 3729, 3730,
3757, 5056, 5091, 7966, 8248, 17122, 17553. Mains, 32-258.
Observations.-The colors vary greatly, but an olive-fuscous shade
tinged with pale yellow is its outstanding character. M. flavescens
has the same combination of colors but grows in hardwood forests
and has a different habit. The habit, however, could easily be
caused by the growth conditions imposed by the broad flat oak leaves
which cover the forest floor. The reddish-brown stains of the gills
and stipe of M. elegans are not given much emphasis here, although
in the specimens I have examined their presence seemed constant.
They develop best in wet, foggy weather of the type which prevails in
western Oregon and Washington in October and November. They