North American species of Mycena.

112 NORTH AMERICAN SPECIES OF MYCENA

distinctive; lamellae adnate, toothed or nearly free, moderately broad
to very narrow, subdistant, 14-18 reach the stipe, one or two tiers
of lamellulae, grayish or becoming white, edges even; stipe 3-7 cm.
long, filiform, equal, flexuous, very fragile, inserted abruptly on
leaves or sparsely strigose-particularly if decumbent-glabrous,
apex pruinose at first, upper portion bluish black in young specimens,
the color fading quickly and soon entirely pale gray or whitish.
Spores 8-10 X 4-5 Au (11-13 X 5-6,u in two-spored forms), narrowly ellipsoid, smooth, hyaline; scarcely amyloid; basidia either
four-spored or two-spored (both quite common in Michigan); pleurocystidia not differentiated; cheilocystidia fairly abundant, 25-37 X
7-11 y, clavate to capitate, apex covered with 5-129 or more projections, sometimes the heads variously branched or irregular, hyaline;
gill trama of vesiculose cells, homogeneous, vinaceous brown in
iodine; pileus trama composed of enlarged cells, those near or at the
surface with verrucose walls, vinaceous brown in iodine, pellicle
poorly formed, of slender hyphae with obtuse protuberances covering
most of their length.
Habit, habitat, and distribution.-Single to gregarious on fallen
leaves of oak and beech during late fall. It is often very abundant
locally in November. It comes up during warm rainy weather between severe frosts. I have examined specimens from New York,
Michigan, Idaho, and Oregon in the United States and from Ontario
in Canada. Because of its size it is difficult to make good herbarium
specimens.
Material studied.-Smith, 32-664, 1175, 1252, 1270, 18207, October 1, November 12, 19, 1931, October 29, 1932 (two-spored),
Michigan.
Observations.-The relatively long, narrow spores are characteristic
of both the four-spored and the two-spored forms and are a distinguishing feature of the species. The color of the pileus is gray at first,
either light or dark, and soon fades to white or retains a watery-gray
disc and striations. I have not observed colors approaching those
described for M. Smithiana by Kiihner. As is frequently true of very
small agarics, the thickness and width of the gills, their attachment
to the stipe, and their spacing are all tremendously variable and must
be used cautiously as taxonomic characters. The large granular or
verrucose hyphae near or on the surface of the pileus that Kuihner
described and illustrated are also present in my material. The
hyphae described as forming the poorly differentiated pellicle are