North American species of Mycena.

174 NORTH AMERICAN SPECIES OF MYCENA

whitish, odor faintly spermatic at times (Ktihner reports it as faintly
fragrant), taste not distinctive; lamellae narrow to moderately broad,
somewhat ascending, close, 16-24 reach the stipe, two or three tiers
of lamellulae, rather thick, whitish to pale incarnate when young,
often sordid pale rufous orange in age, edges even and concolorous
with the fa'ces; stipe 2-7 cm. long, 1-2 mm. thick, tubular, moderately
fragile, equal, the base frequently prolonged and densely strigose
(sometimes forming a slight pseudorhiza), surface white, glabrous or
very finely pruinose-pubescent, becoming yellowish in age, finally
discoloring at times and becoming dark sordid brown (near "mummy
brown").
Spores (6) 7-9 X 5-6.7,, ovoid to somewhat ellipsoid, nonamyloid; basidia four-spored or two-spored (then the spores 8-10 X
6-8, ); pleurocystidia very rare or apparently absent, similar to
cheilocystidia; cheilocystidia numerous, 28-47 X 7-12 A, subcylindric,
subclavate, or somewhat fusoid-ventricose, hyaline, smooth; gill
trama homogeneous, the cells rather broad and interwoven, yellowish
in iodine; pileus trama with a distinct pellicle, a moderately welldifferentiated hypoderm and the remainder filamentous, yellowish in
iodine.
Habit, habitat, and distribution.-Scattered to gregarious on debris
of elm and ash, and on alder debris in Washington, particularly on the
bark of partly decayed logs, late June and early fall; not uncommon
in New York, Michigan, Missouri, and Washington.
Material studied.-Smith, 32-227, 32-244, 32-259, 32-282, 32 -309, 32-332, 32-342, 32-619, 33-722, 776, 1465, 6832, 7628, 7674,
11081, 15239, 17256, five unnumbered collections, Michigan. Atkinson, 23409, 23147, 23369 (as M. adonis). Kauffman, two collections (as M. subincarnata), Michigan. Mains, 1932, Michigan.
Observations.-The habit and consistency of M. roseipallens reminds one very much of M. olida var. americana. Both occur in
similar habitats at the same time of year. The colors readily separate
the two if young carpophores are compared, but in age either one may
become sordid yellowish tan. The almost complete absence of
pleurocystidia distinguishes M. roseipallens from the confusing group
of rosy-colored species centering around M. amabilissima.
78. MYCENA FUSIPES Murrill
Mycologia, 8: 220. 1916
Prunulus fusipes Murrill, North Am. Flora, 9: 337. 1916.
Illustrations: Text fig. 17, nos. 4-5 (p. 173).