The North American species of Psathyrella.

178

MEMOIRS OF THE NEW YORK BOTANICAL GARDEN

[VOL. 24

Lamellae close, broad, depressed-adnate, brownish drab at maturity but dull
cocoa-brown as dried, edges even.
Stipe 4-5 cm long, 3-4 mm thick, equal, fragile, naked, pallid over all.
Spores 7-9 x 4-4.6 a, smooth, apical pore distinct but apex not truncate, shape
in face view ovate to elliptic, in profile obscurely inequilateral to somewhat beanshaped, color in KOH dull cocoa-brown, not darkening readily, in Melzer's reddish
tawny, wall about 0.3 /L thick.
Basidia 4-spored, 20-25x8-10 pt, hyaline in KOH, clavate. Pleurocystidia
abundant, 42-63 x 9-15 a, fusoid-ventricose with elongated neck and subacute to
obtuse apex which in KOH remains granular-incrusted for some time, wall thin
to slightly thickened and hyaline to yellowish in KOH in the ventricose part,
content not distinctive in KOH or in Melzer's. Cheilocystidia saccate-pedicellate
to vesiculose, 22-30 x (8-) 10-16 a, walls thin and smooth or slightly thickened and
yellowish, content not distinctive. Caulocystidia not found.
Pileus with a cuticle of inflated cells several deep, the walls smooth and
yellowish to hyaline in KOH, content of cells not distinctive; trama of pileus of
inflated hyphal cells brownish at first as revived in KOH but fading to yellowish
hyaline, walls smooth. Clamps present. When mounted in Melzer's no distinctive
reaction was noted in any tissue.
Type locality. McCall, Idaho. -
Habit and habitat. Gregarious under spruce and fir, July.
Distribution. Known only from type locality.
Observations. The distinctive features of the species are the stature-reminding one of small basidiocarps of P. candolleana,-the elongate pleurocystidia with
the apical granular incrustation as revived in KOH, medium-sized spores and gill
edges almost entirely made up of clavate to vesiculose cells. The weak coloration
in the wall of the pleurocystidia can be easily overlooked. In crushed mounts the
cystidia tend to break thus indicating a more rigid wall than in most species
in the genus.
135. Psathyrella subfasciculata A. H. Smith, sp. nov.
Pileus 2-3 cm latus, hemisphericus demum late convexus, pallide spadiceus,
ad marginem appendiculatus; lamellae latae, confertae, pallidae demum olivaceobrunneae; stipes 3-4 cm longus, 4-6 mm crassus, siccus, sursum fibrilloso-zonatus;
sporae 8-9 x 4-4.5 (-5) t; pleurocystidia 40-55 (-66) x 10-15 p, fusoide ventricosa,
obtusa; fibulae adsunt. Typus. Sharp 18909 (MICH); legit prope Greenbrier,
Great Smoky Mountains National Park, Tennessee.
Illust. Text Figs. 303-306.
Pileus 2-3 cm broad, convex-hemispheric or finally broadly convex to nearly
plane, atomate, hygrophanous, "snuff brown" moist, "clay color" faded (when
dried nearly drab), margin white-appendiculate, at times splitting. Context rather
thin on disc, very thin on margin, white, odor and taste not distinctive.
Lamellae adnate, rather broad, close, pallid at first, finally "buffy brown" to
"olive-brown," edges pale and fimbriate.
Stipe 3-4 cm long, 4-6 mm thick, dry, equal, whitish, shining, fibrillose, hollow,
with a slight fibrillose ring left by the webby veil.
Spores 8-9x4-4.5(-5) au, smooth, apical pore distinct and apex obscurely
truncate, shape in face view oblong to narrowly elliptic, in profile subelliptic to
obscurely inequilateral, color in KOH cocoa-color slowly changing to chocolatebrown, in Melzer's tawny-red, wall about 0.3 t thick.