North American species of Mycena.

254 NORTH AMERICAN SPECIES OF MYCENA

campanulate or nearly convex, with a conspicuous bloom when
young, soon naked, glabrous, translucent-striate to near the apex
when fresh, becoming sulcate in age, disc "fuscous" to "benzo brown"
(dark grayish brown), "drab" toward the whitish margin, the margin
at first darker grayish brown and usually tinged pale vinaceous on
buttons, soon becoming paler, in age pallid over all except the disc;
flesh very thin and papery in mature pilei, grayish to pallid, odor and
taste not distinctive; lamellae adnate, usually somewhat ascending,
often slightly toothed but readily seceding, close to subdistant, 17-23
reach the stipe, one or two tiers of lamellulae, narrow at first, in age
ventricose and moderately broad, intervenose, white or sometimes
yellowish in age, edges pallid and even; (1) 3-7 cm. long, 1-2.5 mm.
thick, tubular, very fragile, equal or slightly thickened at the base,
covered with a conspicuous bloom at first, the base white-strigose,
soon naked over the upper portion, "hair brown" over all or the apex
pallid, in age pallid over all or the base dingy.
Spores (7) 8-10 X 4-5.5 A, ellipsoid, smooth, amyloid; basidia
four-spored; pleurocystidia rare to scattered, 38-46 X 9-12 (14) A,
broadly fusoid-ventricose with the apices usually forked or branched
(unbranched in young specimens); cheilocystidia numerous, 40-62 X
10-20 py, ventricose and mucronate or the apex with several fingerlike
prolongations, occasionally merely fusoid-ventricose; gill trama
homogeneous, vinaceous brown in iodine; pileus trama with a thin
pellicle, beneath that a well-differentiated hypoderm, the remainder
composed of a relatively narrow band of filamentous tissue, vinaceous
brown in iodine except for the pellicle.
Habit, habitat, and distribution.-Scattered to gregarious or in
clusters of two or three individuals. Usually found on sticks of
Vaccinium corymbosum L. and the soft maple (Acer rubrum), occasionally in spruce bogs, where it may be densely gregarious on the needle
carpet (V. corymbosum has always been found in the locality, however). Most abundant in the spring (early June) but occasionally
fruiting in the fall as well. It is known from New York and Michigan
in the United States and from Ontario and Manitoba in Canada.
Material studied. Smith, 32-4, 32-31, 32-558, 32-559, 33-98,
33-183, 33-380, 63, 1410, 1617, 6232, 15035, October 12, 1929; June
13, 1934; July 13, 1938, Michigan. Bisby, July 8, 1931, Manitoba.
Kauffman, Michigan (as M. debilis).
Observations.-Although it was originally described as cespitose,
I have seldom found fruiting bodies in clusters. The thin, sulcate