North American species of Mycena.

270 NORTH AMERICAN SPECIES OF MYCENA

gray fragile Mycenae. The short-stemmed form of M. atroalboides,
M. pusilla, and M. constans are all characterized by approximately
the same stature and, apparently, by more or less the same color.
From all these M. alcaliniformis is readily separated by the somewhat
different cystidia, fragrance, and more fragile consistency.
128. MYCENA URANIA (Fr.) Gillet
Champ. Fr., 1: 279. 1878
Agaricus uranius Fries, Syst. Myc., 1: 144. 1821.
Illustrations:
Plate 49 A; Text fig. 32, nos. 5-6 (p. 268).
Smith, Mycologia, 27: 601, fig. 2 c.
Pileus 4-10 mm. broad, conic to hemispheric at first, the margin
appressed, becoming broadly umbonate to convex in age, surface
hoary-pruinose but soon naked and dull, appearing rather dry, margin
somewhat sulcate-striate or at times becoming crenate, color "dark
plumbeous" or "deep Varley's gray" when fresh, fading through
"lilac gray" and finally becoming pale drab, the margin usually pallid
when fresh (dark grayish blue when young, becoming lighter and
more bluish, but finally becoming pale drab); flesh thin, fragile, bluish
gray to almost pallid, not changing when bruised, odor and taste not
distinctive; lamellae broadly adnate to distant, white to whitish
when young, becoming bluish or pallid gray, edges even and concolorous with the faces; stipe 1-3 cm. long, 0.5-1 mm. thick, equal,
rigid, and fragile, tubular, pruinose and with a hoary unpolished
appearance, at first "deep Varley's gray" to "pale violet-gray," but
becoming paler (more or less concolorous with the pileus).
Spores 7-9 X 4-5 u, ellipsoid, amyloid; basidia four-spored;
pleurocystidia sporadic, scattered to abundant or apparently absent
on some caps, similar to the cheilocystidia; numerous, 26-34 X 8-12 A,
clavate to subcapitate, the apex covered with short rodlike projections; gill trama homogeneous, the cells becoming distinctly inflated,
vinaceous brown in iodine; pileus trama with a thin, poorly differentiated pellicle, the hyphae of which bear numerous short rodlike
projections, hypoderm well differentiated, the remainder filamentous,
all but the pellicle vinaceous red in iodine.
Habit, habitat, and distribution.-Gregarious on wet or swampy
ground among mosses and decaying leaves in coniferous and hardwood forests, usually found during the late summer and fall. It is