The North American species of Psathyrella.

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MEMOIRS OF TIlE NEW YORK BOTANICAL GARDEN

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first, dingy brownish in age or as dried, thinly fibrillose from remains of the pallid
veil, apex scarcely pruinose.
Spores 7-8.5 x4.5-5 a, smooth, apical pore distinct but apex only obscurely
truncate, shape in face view ovate to elliptic, in profile subelliptic to obscurely
bean-shaped or obscurely inequilateral, color in KOH chocolate-brown becoming
dark chocolate, dark reddish tawny in Melzer's, wall about 0.3 n thick.
Basidia 4-spored, clavate, 18-24x7-9 pu. Pleurocystidia scattered, 32-47x
9-14 A, ventricose with a neck narrowed to 4-4.5 u but ending in a capitellum
5-6.5 / wide, or cystidium varying to broadly and obtusely fusoid and 40-50x
13-16 a, some merely fusoid-ventricose with narrow neck and obtuse apex, all
thin-walled, smooth, and hyaline. Cheilocystidia mostly clavate-pedicellate and
9-14 p wide, hyaline to dingy pale ochraceous.
Gill trama at first with hyphal walls fuscous-brown in KOH but soon fading
to dull cinnamon, smooth or nearly so. Pileus cuticle a palisade of clavatepedicellate cells and vesiculose ones intermingled, or irregularly 2-3 cells deep but
still basically a palisade, walls smooth, brownish to hyaline in KOH, thin. Hyphae
of the subcuticular region dark, almost fuscous-brown in KOH but soon fading
to dull sepia or warm sepia (dull dark cinnamon), walls roughened but becoming
smoother on standing. Clamp connections present.
Type locality. South Fork, Boulder Creek, Owyhee County, Idaho.
Habit and habitat. Gregarious under aspen and fir, June.
Distribution. Idaho.
Observations. The dried specimens resemble in color those of P. umbrinescens.
The pigmentation as seen revived in KOH at first resembles that of P. barlae but
this stage is of short duration and a rusty brown tone is soon evident. The ninepin-shaped pleurocystidia are distinctive but at the same time the overall picture
is one of wide variation in cystidial shape.
391. Psathyrella fuscospora A. H. Smith, sp. nov.
Pileus 1-3 cm latus, late convexus, glaber, castaneus; contextu brunneolus;
lamellae latae, confertae, brunneolae, demum fusco-brunneae; stipes 3-5 cm
longus, 1-2.5 mm crassus, albus, deorsum brunneus; velum sparsum, pallidum;
sporae 7.5-9x 4.5-5 A; pleurocystidia 38-52 x9-15 a, obtuse fusoideo-ventricosa;
fibulae adsunt. Typus. Smith 64951 (MICH); legit prope Payette Lakes, Idaho.
Illust. Text Figs. 849-853.
Pileus 1-3 cm broad, obtusely conic to convex, glabrous except for a few fibrils
along the margin, chestnut-brown to cinnamon-brown when moist, fading to dull
tan and then somewhat wrinkled. Context brownish, fragile, odor and taste not
distinctive.
Lamellae close, broad, adnate, seceding, dull brown at first, fuscous-brown in
age and edges concolorous with faces.
Stipe 3-5 cm long, 1-2.5 mm thick, equal, fragile, whitish above, dark brownish
below; veil pallid, thin and fibrillose.
Spores 7.5-9 x 4.5-5 /, smooth, apical pore evident, shape in face view elliptic
to ovate, in profile subovate to obscurely inequilateral (in mounts from the gills
a fair number of elongated spores also present), color in KOH dark chocolatecolor, in Melzer's tawny reddish, wall about 0.3 u thick.
Basidia 4-spored, 18-25 x 7-9 I, hyaline, subclavate. Pleurocystidia 38-52 x
9-15,, fusoid-ventricose with obtuse apex, smooth, thin-walled, hyaline or in
KOH some with a weakly purplish brown homogeneous cell sap. Cheilocystidia