North American species of Mycena.

EUMYCENA: CORTICOLAE

69

of the trama, the tissue below it of loosely interwoven floccosehyphae,
the pellicle poorly differentiated, its hyphae 4-6, thick and furnished
with short branches or variously and irregularly roughened with obtuse simple or branched projections; caulocystidia abundant and
similar to the cells covering the surface of the pileus.
Habit, habitat, and distribution.-Densely gregarious on dead or
live trees, often covering large areas of the bark. Common in late
fall throughout eastern North America on all kinds of trees but particularly on oak, pine, hop hornbeam, and basswood. It also appears
in the early spring but usually is not so abundant at that time. I
have not yet collected it along the Pacific coast, and I know of no
authentic collections from that area. Overholts (3145) has collected
it on the umbrella pine (Sciadopitys verticillata Sieb. & Zucc.) at State
College, Pennsylvania, during August. Material from New York,
Pennsylvania, Ohio, Michigan, Tennessee, Missouri, and Texas has
been examined.
Material studied.-Smith, 32-279, 32-605, 1745, 4752, 6961, 8981,
14974, November 18, 1931, Michigan. Atkinson, 3967, 16192. Ellis
and Everhardt, North Am. Fungi, 2007. Hesler, 10204. One collection, by L. N. Johnston, Michigan. Four collections by Kauffman,
New York, Michigan. Overholts, 1297, 1527, 2912, 2959, 3043, 3109,
3113, 3131, 3145, 5769, 13139, 13147, 14998. Patterson, 1941. Routien, 655. E. A. Smith, 1935, Texas.
Observations.-The dark-purplish color of the whole fruiting body
is at first obscured by the canescent covering of cystidia. The purple
soon fades, and before the pileus becomes naked the colors have
changed to vinaceous brown.
I have not examined authentic material of M. Meliigena, but from
the description it appears that there are no characters by which it
could be separated from M. corticola. The "papillate" spores seem
to be the only remote possibility, and I strongly suspect that the
authors were describing the apiculus on the spore rather than the
character of its surface.
12. MYCENA PSEUDOCORTICOLA Kiihner
Le Botaniste, 26: 368. 1934
Illustrations: Lange, Flora Agar. Dan., 2, pl. 57 El, E2. 1936.
Pileus 3-14 mm. (2-8 mm. across the base), globose when young,
then conic, campanulate, or hemispheric, expanding less than in M.:.:,