North American species of Mycena.

EUMYCENA: TYPICAE

269

127. MYCENA ALCALINIFORMIS Murrill
Mycologia, 8: 220. 1918
Prunulus alcaliniformis Murrill, North Am. Flora, 9: 331. 1916.
Illustrations:
Plate 35 E; Text fig. 32, nos. 2, 4.
Murrill, Mycologia, 4, pl. 68, fig. 9 (as M. vexans).
Pileus 1-2 cm. broad, obtusely conic to convex, becoming broadly
convex, obtusely campanulate or with the disc flattened somewhat,
margin appressed against the stipe at first, often flaring in age and
often becoming crenate, surface moist, even, glabrous, very hygrophanous, conspicuously striate to the disc when moist, colors "fuscous" to "hair brown" over the disc and striae, grayish white elsewhere, fading quickly to pale cinereous; flesh very fragile, thin and
membranous, grayish to whitish, taste not distinctive, odor faintly
fragrant at first, soon fading; lamellae ascending-adnate with a slight
tooth, subdistant to distant, 9-13 reach the stipe, one or two tiers of
lamellulae, moderately broad, grayish, with whitish even margins;
stipe 2-4 cm. long, 1-2 mm. thick, equal or tapered slightly at the
base, hollow, very fragile, terete or compressed, base sparsely mycelioid, glabrous and polished above, translucent, concolorous with the
pileus or paler, often whitish above.
Spores ellipsoid, 8-10 X 4-5,, amyloid (reaction strong); basidia
four-spored, 26-29 X 7-8 A; cheilocystidia clavate, hyaline, with
obtuse fingerlike projections over the enlarged portion, often with
wavy outlines or variously contorted; pleurocystidia not differentiated; gill trama vinaceous brown in iodine; pileus trama with a thin
pellicle, beneath it a region of vesiculose cells (about half the thickness
of the cap), the remainder of moderately broad cells, all but the
pellicle vinaceous brown in iodine.
Habit, habitat, and distribution.-Densely gregarious on needle
beds, especially those of white pine, in spring, late summer, and fall;
Alabama, Massachusetts, New York, Michigan, and Oregon in the
United States and Ontario in Canada.
Material studied.-Smith, 703, 711, 742, 3475, 4814, 5042, 8927.
Overholts, September 6, 1935, Ontario. Stuntz, F 485.
Observations.-Murrill described the species as occurring on debris
of spruce. In the Adirondacks I have found it exceptionally abundant under white pine. In Oregon I collected it sparingly under
Pinus contorta. The very fragile consistency, conspicuously striate
pileus, cheilocystidia, and fragrance readily separate it from other