The North American species of Psathyrella.

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MEMOIRS OF THE NEW YORK BOTANICAL GARDEN

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grayish brown and finally purplish gray, as dried fuscous-brown at least near the
margin; edges even.
Stipe 6-8 cm long, 4-6 mm thick, equal, hollow, fragile, striate, whitish at first,
later sordid to brownish below, with a thin coating of appressed fibrils; veil
rudimentary.
Spores 7-9 x 4-5 i, smooth, apical pore distinct but apex not truly truncate,
shape in face view elliptic to subovate, in profile obscurely bean-shaped to
obscurely inequilateral, color in KOH cocoa-brown but becoming chocolate-brown,
in Melzer's reddish tawny, wall about 0.3 u thick.
Basidia 4-spored, 18-26 x 8-10 /, clavate, hyaline. Pleurocystidia 38-60 x
9-18 a, utriform to fusoid-ventricose with broadly rounded apex, rarely one with
subacute apex, in most the wall pale ochraceous in the distal portion and with the
wall thickened to about 0.3 a, smooth, cell content not distinctive. Cheilocystidia
ochraceous in KOH and usually smaller (and more of them clavate) than for the
pleurocystidia.
Pileus cuticle a staggered palisade of clavate-pedicellate and inflated cells in
a thick layer, hyaline in KOH, walls thin and cell content not distinctive. Hyphae
of the subcuticular region smooth to weakly incrusted with ochraceous (in KOH)
deposits; trama below the cuticle ochraceous-hyaline in KOH. Clamps present.
Type locality. Dynamite Hill Road, Silver River Area, Baraga County,
Michigan.
Habit and habitat. Gregarious on leaf mold in a hardwood forest, July.
Distribution. Michigan.
Observations. The bitter taste, utriform cystidia with their slightly thickened
ochraceous walls (as revived in KOH) in the distal portion, and the overall
resemblance to P. spadiceogrisea are distinctive.
Material examined. Michigan: Ammirati 2925 (Type).
327. Psathyrella spadiceogrisea (Fries) Maire, Mem. Soc. Sci. Nat. Maroc 45:
113. 1937.
Agaricus spadiceogriseus Fries, Epicr. Syst. Mycol. 232. 1838.
Psathyra spadiceogrisea (Fr.) Kummer, Fiihr. Pilzk. 70. 1871.
Psilocybe spadiceogrisea (Fr.) Boudier, Icones Mycol. 4: 68. 1911.
Drosophila spadiceogrisea (Fr.) Quelet, Enchir. Fung. 117. 1886.
Illust. Boudier, 1. c. pl. 135. P1. 84, fig. c; Text Figs. 709, 710.
Pileus (1-)2-8 cm broad, broadly conic when young, soon convex and finally
plane or with a low umbo, surface at first with inconspicuous patches of fibrils
on or near the margin from the rudimentary white or pallid fibrillose veil, soon
entirely glabrous, smooth to rugulose, moist and translucent striate or at times the
margin slightly furrowed in age, "russet" to "cinnamon-brown" (rusty brown),
hygrophanous and fading to "avellaneous" or "wood brown," atomate when faded.
Context thin, very fragile, pallid brownish, odor fungoid, taste mild.
Lamellae close, 18-27 reach the stipe, 2-3 tiers of lamellulae, bluntly adnate
or with a slight decurrent tooth, moderately broad (3-4 mm), pallid brownish
young, near "wood brown" (dark avellaneous) at maturity.
Stipe (1-)4-12 cm long, (1-)2.5-6 mm thick, slightly narrowed upward or
equal, very fragile, hollow, whitish above, pallid to sordid tan downward, sparsely
fibrillose at first from veil remnants, glabrous in age, apex pruinose at first,
glabrous in age, apex sometimes striate from the gill impressions.
Spores 7-9 (-10) x 5-5.5 (-6) I,, smooth, apical pore distinct and apex truncate