North American species of Mycena.

314 NORTH AMERICAN SPECIES OF MYCENA

"plumbeous black" when young (especially toward the apex), fading
to "army brown," "bone brown," or pale grayish, often white in age.
Spores 8-10 X 5-6, ellipsoid, amyloid; basidia four-spored;
pleurocystidia abundant, 60-90(110) X 8-16 g, smooth, hyaline,
subcylindric to fusoid-ventricose; cheilocystidia similar but shorter
(up to 70,u); gill trama homogeneous, vinaceous brown in iodine;
pileus trama with a well-differentiated pellicle and hypoderm, the
remainder filamentous, all but the pellicle pale vinaceous brown in
iodine.
Habit, habitat, and distribution.-Gregarious to cespitose on conifer
logs and debris; most abundant during late May and early June in the
vicinity of Ann Arbor. I have examined material from Tennessee,
Pennsylvania, and Michigan.
Material studied.-Smith, three collections, 32-12, May 25, 1932,
Michigan. Hesler, 3816, 11415. Overholts, 22749.
Observations.-In his notes Overholts described the pileus as pale
watery brown to "Saccardo's umber" or "snuff brown," and the
spores as measuring 8-10 X 5-7,. Thus it appears that the same
range in color noted for M. alcalina is present in this species. The
collections just listed have been identified as Singer's species chiefly
on the basis of the very large cystidia and the odor. Kiihner reduced
M. macrocystidiata to synonymy with M. metata (M. leptocephala in
this work). The cystidia of the latter fungus, which has been collected abundantly in North America, have never approached the
measurements given by Singer. Consequently, although the species
described here is a robust Mycena, it does not seem wise to separate it from M. macrocystidiata. The variations in stature observed
for M. alcalina locally are no greater than those indicated by Singer's
original description and my notes. M. macrocystidiata and M. niveipes
have many characters in common, but their appearance readily distinguishes them. Compare Plates 67 and 68 with Plate 69.
TYPICALLY LIGNICOLOUS SPECIES; CYSTIDIA
NOT GREATLY ELONGATED
153. MYCENA ALCALINA (Fr.) Quelet
Champ. Jura et Vosges, p. 105. 1872
Agaricus alcalinus Fries, Syst. Myc., 1: 142. 1821.
Mycena vexans Peck, Ann. Rep. New York State Mus., 38: 85. 1885.