North American species of Mycena.

EUMYCENA: TYPICAE

273

Ricken, Die Blatterpilze, 2, pl. 110, fig. 9.
Smith, Am. Journ. Bot., 22, pi. 1, fig. 1.
Pileus (5) 10-25 mm. broad, equally high, obtusely conic to convex, sometimes campanulate, the margin often flaring and split
radially, surface at first covered with a faint bloom, slowly becoming
naked, glabrous, somewhat translucent-striate but usually with a
rather dry appearance even before fading, usually "army brown" to
"fawn color" or "avellaneous" over the disc, margin "warm buff" to
ashy gray or fading and becoming whitish, disc sometimes "olive
brown," sometimes the entire pileus pale cinereous with only a tinge
of vinaceous; flesh thin, pallid to avellaneous, very fragile, odor sharp,
rather faint (hardly alkaline), taste slight, acidulous; lamellae ascending-adnate, usually toothed, close, narrow to moderately broad, white
at first, soon tinged creamy to "vinaceous buff" (tinged dull incarnate), edges even and pallid; stipe 3-9 cm. long, 1-2.5 mm. thick, very
fragile, equal, tubular, strict or flexuous, sometimes bluish black when
young but, if so, quickly fading to "wood brown" or paler avellaneous,
apex pallid, faintly pruinose above, translucent when moist, glabrous
except for the strigose base.
Spores 7-9 X 4-5 t or 8-10 (12) X 4-6,, smooth, narrowly
ellipsoid to somewhat pear-shaped, amyloid; basidia usually two- or
three-spored, occasionally four-spored; pleurocystidia and cheilocystidia similar, rare to scattered on sides, abundant on edges of the
lamellae, 27-38 X 9-17,, clavate to capitate, pedicel usually slender,
head echinulate; gill trama homogeneous, dark vinaceous brown in
iodine; pileus trama with a thin but sharply differentiated pellicle, a
distinct hypoderm and the remainder filamentous, all but the pellicle
deep vinaceous brown in iodine.
Habit, habitat, and distribution.-Scattered to gregarious under
conifers, common in the fall; Pennsylvania, New York, Michigan,
Idaho, Washington, Oregon, and California in the United States and
from Nova Scotia to Ontario in Canada.
Material studied.-Smith, 32-601, 32-636, 32-645, 32-651, 64, 90,
744, 1253, 3328, 3390, 3444, 3715, 4381, 6155, 7784, 7945, 8029, 8059,
8106, 8624, 8741, 8813, 8836, 8919, 8926, 9043, 9076, 14156, 14679,
18119. Kauffman, Idaho and Michigan. Mains, 31-666, 5187,
November 16, 1931; August 9, 1932; September, 1935. Overholts,
19398. Slipp, UIFP: 3231, 3675. Wehmeyer, 518, 518a, 518b.
Weir, October 9, 1920.
Observations.-This species is characterized by its vinaceous-brown