North American species of Mycena.

48 NORTH AMERICAN SPECIES OF MYCENA

four-spored, rarely two-spored; no pleurocystidia seen; cheilocystidia
abundant, 18-28 X 9-15 P, clavate, the enlarged portion covered
with small blunt projections or densely verrucose, hyaline; gill trama
vinaceous brown in iodine; pileus trama covered with a layer or coating of inflated or globular readily detachable verrucose cells 18-24 X
10-30,, tissue beneath colored vinaceous brown in iodine; stipe tissue
yellow to hyaline in iodine, surface covered with long or short verrucose cells or filaments 60-300 X 9-20 A, their apices obtuse.
Habit, habitat, and distribution.-Single to scattered on conifer
needles, fern debris, or old leaves during spring, summer, and fall.
It is known from Alabama, North Carolina, Tennessee, New York,
Ohio, Michigan, and Washington in the United States and from
Ontario and British Columbia in Canada. It has also been found in
British Honduras. Because of its size and delicate texture it is
easily overlooked or neglected. Mr. Walters found it on Osmunda
fibers in a greenhouse near Cleveland, Ohio.
Material studied.-Smith, 32-19, 32-20, 32-230, 33-576, 33-597,
33-933, 715, 4713, 7026, 7471, 10741, 10906. Atkinson, New York
(as M. tenerrima). Burke, Alabama. Mains, 3740, 3858, 4050.
Sharp, 5170. Walters, November 15, 1940, Ohio.
Observations.-I have never observed the cheilocystidia of this
fungus to have the long needlelike projections which characterize
western collections of typical M. tenerrima. In regard to the identity
of M. osmundicola and M. tenerrima var. carpophila Lange there
seems to be no doubt that the variety should be referred to the former
as a synonym. At least I have found material on beech mast which
checks perfectly with M. osmundicola and which does not have the
characteristic cheilocystidia of M. tenerrima. In his first publication
(1914, p. 35) Lange stated, of the variety, "for the rest microscopically like 50a" (M. tenerrima). But for the latter (which is
no. 50a, referred to) he described the cheilocystidia as "apex either
obtuse, obtuse with hairlike appendix or gradually tapering off into a
hairlike appendix." Since he makes no definite statement whether
this variation was noted on a single cap or on different collections,
it is impossible to be certain in regard to the shape of the cheilocystidia in the variety.
Lange believed that M. osmundicola was an introduced species,
and thus was obviously not expecting to find it native to Denmark.
In North America it is apparent that it has adapted itself to a wide
range of substrata and is very widely distributed. It is possible, of