North American species of Mycena.

EUMYCENA: TYPICAE

(in age) brownish pileus with its whitish margin and the broad mucronate cheilocystidia distinguish it. The cheilocystidia are its most
distinctive character. The faint vinaceous tint along the edge of the
pileus is a fairly reliable character, but must be determined from
immature pilei. M. plumbea has somewhat the same type of cheilocystidia, though it has a distinctly different appearance as well as
slightly larger spores.
118. MYCENA ATROCYANEA (Fr.) Gillet
Les Hymen., p. 271. 1874
Agaricus atrocyaneus Fries, Syst. Myc., 1: 147. 1821.
Mycena nigricans Bresadola, Fungi Trid., 1: 33. 1882.
Illustrations:
Plate 47 C; Text fig. 30, nos. 4, 7 (p. 253).
Bresadola, Icon. Mycol., 5, pl. 245.
Pileus 5-15 mm. broad, obtusely conic to convex, the margin appressed, becoming broadly convex to slightly umbonate, surface at
first hoary because of the presence of a glaucous bloom, slowly becoming naked and moist, opaque at first, at times becoming faintly striate
when mature, sometimes becoming rugulose, scarcely fading, color
"Chaetura black" and fading to "hair brown" or "drab" near the
edge (black to bluish black when fresh and fading to dark sordid
gray); flesh thin but rather cartilaginous, two-layered, upper layer
dark blackish brown, lower layer pallid (under a hand lens), no odor,
taste not recorded; lamellae adnate or toothed, distant, narrow to
moderately broad, pale gray, edges even and dark grayish; stipe 2-5
cm. long, about 1 mm. thick, extending a short distance into the soil
but hardly rooting, equal, tubular, rigid, and cartilaginous, base
white-strigose, apex hoary, concolorous with the pileus (apex seldom
paler).
Spores 8-10 X 5-6 u, ellipsoid, amyloid; basidia four-spored;
pleurocystidia rare to scattered, 38-54 X 8-12 u, fusoid-ventricose,
subelavate or sometimes irregular but seldom branched; cheilocystidia
abundant, similar to pleurocystidia; gill trama with a thin surface
pellicle, the hyphae of which bear numerous short projections, beneath
the pellicle a broad hypoderm of greatly enlarged cells filled with a
dark-brown sap, the remainder made up of broad but filamentous
hyphae.
Habit, habitat, and distribution.-Gregarious on humus under