North American species of Mycena.

358 NORTH AMERICAN SPECIES OF MYCENA

22. Pileus 2-5 mm. broad; cheilocystidia 3-7 j, broad; scattered on old
canes of Rubus................................ 177. M. Brownii
22. Pileus larger; strictly terrestrial................................ 23
23. Spores 6-8 X 3-4, (4-spored).................... 183. M. concolor
23. Spores (7) 8.5-10 X 4-5.5 M,........................ 182. M. misera
173. MYCENA IIIEMALIS (Fr.) Quelet
Champ. Jura et Vosges, p. 110. 1872
Agaricus hiemalis Fries, Epicr. Syst. Myc., p. 119. 1838.
Omphalia corticola Peck, Ann. Rep. New York State Mus., 44: 18. 1891.
Omphalopsis corticola Murrill, North Am. Flora, 9: 312. 1916.
Illustrations:
Plate 53 B; Text fig. 14, nos. 5-6 (p. 154).
Beardslee and Coker, Journ. Elisha Mitchell Sci. Soc., 40, pl. 23 (upper
figures).
Fries, Icon. Sel. Hymen., 1, pi. 85, fig. 1.
Lange, Flora Agar. Dan., 2, pl. 54 A.
Peck, Ann. Rep. New York State Mus., 44, pl. 2, figs. 8-12.
Pileus (2) 5-15 mm. broad, conic to convex, often papillate, the
disc usually depressed around the papilla, surface smooth, glabrous,
translucent-striate when moist, coarsely sulcate at least along the
margin in age, the margin often irregular or wavy, color variable, disc
grayish to avellaneous, the margin whitish, sometimes quite dark
over the central portion and the margin pale grayish in buttons but
soon fading to whitish; flesh membranous but fragile, pallid avellaneous, odor and taste not distinctive; lamellae subdistant to distant,
(6) 9-15 reach the stipe, one or two tiers of lamellulae, broadly adnate
or with a decurrent tooth, narrow to broad, edges even; stipe 5-7 mm.
long, less than 1 mm. thick, equal, inserted on the substratum, fragile,
whitish, very finely pruinose-pubescent over all under a lens but soon
glabrous, base scarcely strigose.
Spores 8-9 (10) X 4.5-6,, ellipsoid to somewhat ovoid, not
amyloid; basidia two-spored; pleurocystidia not differentiated; cheilocystidia rare, clavate to fusoid-ventricose, hyaline, 26-33 X 7-9 j;
gill trama homogeneous, yellowish in iodine; pileus trama yellowish
in iodine, pellicle thin, hypoderm not distinct, tramal body filamentous.
Habit, habitat, and distribution.-Single or scattered on tree trunks
of soft maple, willow, or elm; Tennessee, New York, and Michigan.
Rare.