North American species of Mycena.

EUMYCENA: OMPHALIARIAE

359

Material studied. -Smith 15530. Hesler, 5225, 6298, 13824.
Mains, November 19, 20, 1931.
Observations.-Characteristically small species such as this often
exhibit great variation in many of the macroscopic characters usually
emphasized in classifying members of this genus, and hence it is not
surprising to find what appear to be rather great differences in the
descriptions of this species by different authors. The width of the
gills is a good example. It varies from narrow to very broad, and the
attachment varies accordingly. As interpreted here, this fungus is
merely a small grayish or whitish Mycena with fusoid cheilocystidia,
a relatively short stipe, and a tendency to grow on tree trunks or
pieces of bark. The stipe is likely to be more pubescent downward
and a bit longer than that of M. corticola. Kiihner (1938) has given
rather complete accounts of both typical material and related forms.
Except for the two-spored basidia, my collection is closest to his
typical form.
A study of Peck's type of Omphalia corticola revealed that in all
probability it belongs here. Cystidia were not found on the gill
edges, but the material was very scanty, and since cheilocystidia are
sometimes rare in M. hiemalis, their apparent absence in 0. corticola
cannot be given a great deal of emphasis. The base of the stipe in
the latter species was described as brownish, but this could have been
a discoloration caused by age.
174. MYCENA SPEIREA (Fr.) Gillet
Les Hym6n., p. 280. 1874
Agaricus speireus Fries, Syst. Myc., 1: 159. 1921.
Omphalia speirea Quelet, Champ. Jura et Vosges, p. 240. 1872.
Omphalia camptophylla Berkeley, English Flora, 5: 62. 1836.
Omphalia tenuistipes Lange, Dansk Bot. Arkiv, 6 (5): 16. 1930.
Illustrations:
Plate 86 A; Text fig. 44, nos. 2-3 (p. 371).
Bresadola, Icon. Mycol., 5, pl. 224, fig. 4.
Fries, Icon. Sel. Hymen., 1, pl. 78, fig. 2.
Lange, Flora Agar. Dan., 2, pl. 61 E (as var. tenuistipes).
Smith, Pap. Mich. Acad. Sci., Arts, and Letters, 19, pl. 43, fig. 2.
Pileus 5-10 mm. broad, convex or obtuse when young, the margin
straight, becoming plane, slightly umbilicate or papillate and slightly
depressed around the papilla, surface very faintly pruinose and soon
naked, moist or appearing dry, lubricous when wet, "fuscous" on the