The North American species of Psathyrella.

130

MEMOIRS OF THE NEW YORK BOTANICAL GARDEN

[VOL. 24

Pileus 2.5-5 cm broad, convex, expanding to plane or the margin uplifted,
glabrous, moist, hygrophanous, margin denticulate with submembranous patches
of the broken veil, colors dark rusty brown to chestnut fading to a reddish tan.
Lamellae close, narrow, adnate, dull brown when young and dark rusty brown
when mature, in drying becoming practically concolorous with the pileus.
Stipe 4-11 cm long, 2.5-7 mm thick, equal or slightly enlarged below, hollow,
fragile, whitish to pale honey-color when fresh but becoming reddish-fulvous over
basal area and the basal part drying ferruginous-red.
Spores 7-10 x 4-5 A, smooth, apical pore distinct and apex somewhat truncate
shape in face view elliptic to ovate, varying to suboblong, in profile obscurely
bean-shaped to subelliptic, color in KOH dull cocoa-color but soon chocolatebrown, in Melzer's tawny-red, wall about 0.3-0.4 g thick (in Melzer's).
Basidia 4-spored, hyaline in KOH, clavate, 17-23x7-9 /. Pleurocystidia
36-48x10-16 /, fusoid-ventricose with thick neck and broadly rounded apex
varying to utriform or ovate- to elliptic-pedicellate (as seen in optical section),
wall thin, hyaline; with granular (or coagulated) debris over the apical region
in many as revived in KOH but this slowly dissolving. Cheilocystidia 30-42X
9-14 g, fusoid-ventricose with a short neck and obtuse apex, thin-walled, hyaline.
Gill trama regular, hyaline in KOH. Pileus trama hyaline or only in the
subcuticular region weakly brownish in thick sections, walls smooth and thin.
Cuticle of pileus of inflated hyaline thin-walled cells in a layer 2-4 deep. Clamp
connections present.
Type locality. Cleveland Heights, Ohio.
Habit and habitat. Cespitose on decaying hardwood logs, June.
Distribution. Michigan, Ohio.
Observations. This species might be regarded as a robust variant of P. septentrionalis. The spores and shape of the pleurocystidia indicate this. It is distinguished as a species by the almost colorless pileus trama as revived in KOH
(this is important in such a darkly pigmented Psathyrella!), the material adhering to the pleurocystidia, and the long stipes which become rusty red at the base
in drying.
Material examined. Michigan: Smith 78007. Ohio: Walters 6-8-40 (Type).
85. Psathyrella hololanigera (Atkinson) A. H. Smith, comb. nov.
Hypholoma hololanigerum Atkinson, Ann. Mycol. 7: 371. 1909.
Drosophila hololanigera (Atk.) Murrill, Mycologia 14: 70. 1922.
Illust. Text Figs. 213, 214.
Pileus 2-2.5 cm broad, oval to convex, watery brown, hygrophanous, as it dries
becoming pale ochraceous-buff to pinkish buff, covered by long dense delicate
whitish fibrous scales which are superficial and soon disappear, not striate.
Context fragile.
Lamellae elliptic, adnate, purplish brown, whitish on the edges.
Stipe 6-7 cm long, 4-5 mm thick, slender, hollow, fragile, even, white with a
very pale pink tint; veil at first forming a volva at the time the veil breaks.
Spores 7-9x4-4.5 A, smooth, apical pore present and readily visible under
ordinary magnifications, shape in face view broadly and bluntly fusoid varying
to subelliptic, in profile somewhat inequilateral, color as revived in KOH pale
chocolate-gray, wall about 0.4, thick.
Basidia 4-spored, 18-24 x 6-8,u, clavate, hyaline in KOH. Pleurocystidia
38-50 x 10-16 A, scattered, with a slender pedicel, a broadly ventricose midportion