North American species of Mycena.

448 NORTH AMERICAN SPECIES OF MYCENA

Pileus (5) 10-20 mm. broad, conic to campanulate, becoming
expanded-umbonate, the margin usually remaining somewhat decurved, blackish to fuscous around the disc or on the umbo, nearly
avellaneous on the margin, fading to grayish in age with the disc
darker, sometimes slightly translucent-striate when mature, pruinose
from projecting cystidia when young, glabrescent and subviscid at
maturity; flesh very cartilaginous and tough, pallid grayish, no odor,
taste slightly disagreeable; lamellae narrowly adnate or attached only
by a tooth, subdistant, moderately broad, pure white or pale cinereous, intervenose, pruinose from projecting cystidia; stipe 2-7 cm.
long, 1-2 mm. thick, with a well-developed pseudorhiza, tough and
cartilaginous, flexuous, hollow, densely pruinose-pubescent, pallid to
brownish above, blackish or sordid gray below, sometimes sordid
ochraceous toward the base in age.
Spores subglobose, 7-8.5,, covered with scattered blunt, short
rodlike protuberances, yellowish in iodine; basidia two-spored; pleurocystidia very abundant, 60-85 X 10-16,, fusoid-ventricose with a
long neck, smooth or incrusted; cheilocystidia similar but shorter
and more obese; gill trama homogeneous, pale yellow in iodine; pileus
trama homogeneous beneath a thin pellicle, the hyphae of which are
covered with numerous short rodlike projections, pilocystidia similar
to the pleurocystidia, originating in the pellicle; stipe covered with
long cystidium-like hairs.
Habit, habitat, and distribution.-Single or in clusters of two or
three carpophores on humus and debris, usually around stumps and
logs; New York and Michigan. Rare.
Material studied.-Smith, 32-473, 32-571, 33-893, 6482, 7257,
7627, 15259, 17253, 17956, Michigan, October 5, 1932. Kauffman,
August 14, 1912, Michigan. Peck, New York (as a variety of M.
galericulata).
Observations.-The distinguishing characters of this fungus are:
first, its pellicle of slender hyphae covered with short projections;
second, the smooth cystidia; and, third, the presence of a well-developed pseudorhiza. The pruinose-pubescent stipe and pileus,
tough consistency, and rough spores are not specific in this group.
Kiihner lists M. lasiosperma Bresadola sensu Kauffman, M. trachyspora Rea sensu Smith, and M. nodulosa Smith, the last questionable,
as synonyms of M. bryophila. Since Bresadola illustrated M. lasiosperma as having curiously branched cystidia, a species in which they
are smooth should not be referred to it, as has been done by Kauffman