The North American species of Psathyrella.

1972]

PSATHYRELLA

303

convex, surface glabrous, moist and hygrophanous, color dark russet to cinnamonbrown and shining when moist, dingy tan when faded and drying, dull cinnamon,
margin incurved at first. Context thin, fragile, odorless.
Lamellae narrow, close, adnate seceding, dingy cinnamon when young,
chocolate-brown mature and dark vinaceous-brown ("bone brown") in age, edges
whitish.
Stipe 4-6 cm long, 3-5 mm thick, equal, fragile, white, naked (no veil present),
apex faintly pruinose.
Spores 9-12 x 5-6 JL, smooth, apical pore distinct and apex truncate, shape in
face view oblong to broadly elliptic or ovate, in profile elliptic to obscurely
inequilateral, color in KOH dark cocoa-color slowly becoming chocolate-brown,
in Melzer's reddish tawny, wall about 0.4, thick.
Basidia 4-spored, clavate, 18-25x7-9 a, hyaline in KOH. Pleurocystidia
scattered, 34-48 x 12-17 )u, fusoid-ventricose with broadly rounded to obtuse apex,
neck 8-10 f thick, wall thin, smooth and hyaline, cell content not distinctive.
Cheilocystidia clavate to broadly and obtusely fusoid, 10-18 K wide, thin-walled,
hyaline. Pileus cuticle a layer of vesiculose cells 2-3 deep, walls yellowish to
hyaline and thin. Hyphae of the context strongly vinaceous and heavily incrusted
with pigment. Clamp connections present.
Type locality. Wilderness Park, Emmet County, Michigan.
Habit and habitat. Gregarious on burned soil (where a brush pile had been
burned), September.
Distribution. Known only from the type locality.
Observations. The diagnostic features of this species are the medium large
cocoa-colored spores, the habitat, lack of a veil, shining white stipe and shining
pileus when wet.
272. Psathyrella ramicola A. H. Smith, sp. nov.
Pileus 1-2 cm latus campanulatus vel convexus, demum distincte atomatus,
avellaneus; lamellae confertae latae brunneolae demum cinnamomeo-brunneae;
stipes 3-5 cm longus, 1-1.5 mm crassus, pallidus sursum pruinosus, deorsum sparse
fibrillosus, glabrescens, demum sordide brunneus; sporae 9-12 x 5.5-6.6 /; pleurocystidia (48-) 55-72 x 8-12 (-14) i, fusoide ventricosa, subcapitata; fibulae adsunt.
Typus. Smith 23922 (MICH); legit prope Cherryville, Oregon.
Illust. Text Figs. 578-581.
Pileus 1-2 cm broad, obtusely conic becoming obtusely campanulate to convex, all pilei faded and coarsely atomate when collected, color near "avellaneous,"
surface checking circumferentially, margin slightly uneven and with a few fibrillose veil remnants on the smallest pilei. Context very thin and fragile, pallid when
faded, odor none, taste not distinctive.
Lamellae close, broad, pallid brownish becoming cinnamon-brown, broadly
adnate, edges white and floccose.
Stipe 3-5 cm long, 1-1.5 mm thick, equal, hollow, fragile, pallid and pruinose
over upper half, lower portion pruinose or with a few appressed fibrils and
becoming dingy brown on aging.
Spores 9-12 x 5.5-6.6 /, smooth, apex somewhat truncate from a distinct apical
pore, shape in face view very broadly elliptic, in profile broadly elliptic to
obscurely inequilateral, color dark dull reddish brown in water mounts when
fresh, dingy date brown when first revived in KOH but slowly becoming chocolatebrown, in Melzer's pale tawny, wall less than 0.5 /u thick.