The North American species of Psathyrella.

402 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN [VOL. 24
Lamellae broad, adnate, distant or subdistant, dark chocolate-brown, edges
even.
Stipe 1-1.5 cm long, 1 mm thick, equal, almost concolorous with pileus in age
or when dried, with scattered evanescent fibrils.
Spores 8-10 x 5-6.5 /A, smooth, apical pore distinct but apex not truly truncate
(merely a hyaline spot which does not affect the contour of the spore apex), shape
in face view broadly elliptic to broadly ovate, occasionally truncate at base and
obscurely angular, in profile broadly subelliptic to broadly and obscurely
inequilateral. Color in KOH soon becoming dark chocolate-color, in Melzer's
bay, wall about 0.3 A thick.
Basidia 4-spored, 18-24x9-11 u, clavate, hyaline in KOH. Pleurocystidia
32-46x9-13 /, fusoid-ventricose with obtuse to subacute apex, or fusoid to a
subacute apex, wall thin, smooth and hyaline, cell content not distinctive. Cheilocystidia more or less similar to pleurocystidia.
Gill trama bright rusty brown in KOH, slowly fading to tawny-cinnamon or
paler, color often in the wall thickenings near or at the septa. Pileus trama dark
rusty cinnamon from numerous pigmented incrustations on the hyphae and from
wall thickenings. Cuticle of pileus of inflated cells several deep and with medium
to pale rusty cinnamon to ochraceous-cinnamon walls, the walls thin and smooth.
Clamps present.
Type locality. Goose Lake, near New Meadows, Idaho.
Habit and habitat. Scattered on soil in a wet mountain meadow, July.
Distribution. Idaho, Washington.
Observations. The cuticular cells of the pileus are colored somewhat as in
P. tsugae and other species inhabiting wood of species of conifers. At first sight
the species reminds one of a Psilocybe subg. Deconica but the anatomy of the
basidiocarp does not support the impression.
Material examined. Idaho: Smith 65134, 65135 (Type). Washington: Smith
48034, 48076.
379. Psathyrella boulderensis A. H. Smith, sp. nov.
Pileus 1-2 cm latus, conicus vel convexus, glaber, subcastaneus; contextu subcastaneus; lamellae fusco-brunneae, latae, conferte, late adnatae; stipes 1-3 cm
longus, 1.5-2.5 mm crassus, pallidus, deorsum brunneus, glaber, sursum pruinosus;
sporae 7-9.5 x4-5 A; pleurocystidia 38-56 x 9-15 p, fusoide ventricosa, obtusa;
fibulae adsunt. Typus. Smith 58670 (MICH); legit prope Boulder Lake, McCall,
Idaho.
Pileus 1-2 cm broad, obtusely conic expanding to broadly conic or convex,
surface glabrous, moist, hygrophanous, when young dark chocolate-color and
fading to dark dull tawny, margin naked (no veil present). Context thin, very
dark brown, fragile, odor and taste not distinctive.
Lamellae as dried chocolate-black, dark dull brown when young becoming
chocolate-brown when mature, broad, close, broadly adnate, seceding; edges even
and whitish.
Stipe 1-3 cm long, 1.5-2.5 mm thick, equal or nearly so, fragile, pallid and
weakly pruinose near apex, dull brown below and finally almost so over all.
Spore deposit dark chocolate-brown. Spores 7-9.5 x 4-5 p, smooth, apical pore
distinct and spore apex obscurely truncate, shape in face view elliptic to narrowly
ovate, varying toward oblong, in profile obscurely inequilateral to subovate, color