The North American species of Psathyrella.

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MEMOIRS OF THE NEW YORK BOTANICAL GARDEN

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rudimentary veil, moist and hygrophanous, "russet" to "Mars brown" and becoming "ochraceous-tawny" before fading, hygrophanous, fading to "cinnamon-buff"
in young pilei and "wood brown" in old ones, faded parts becoming dingy pinkish
(near vinaceous-fawn), striate when moist, smooth and atomate when faded.
Context equal, very thin and fragile, concolorous with the surface, odor and taste
not distinctive.
Lamellae adnate, somewhat ascending, readily seceding, close to subdistant,
18-20 reach the stipe, almost equal, moderately broad (3 mm), pallid, soon pale
fuscous-brown; edges even, none seen with pinkish margins.
Stipe 4-6 cm long, 1.5-2 mm thick, equal, cartilaginous-brittle, stuffed with a
white pith which can sometimes be removed in the form of a thin rod, sometimes
hollow, white, grayish white or tinged dingy buff over lower part, decorated below
with small patches of fibrils, glabrescent, faintly pruinose toward the apex.
Spores 11-14 x 6-7 u, smooth, apical pore well developed and spore apex
truncate, shape in face view oblong to narrowly elliptic, in profile narrowly elliptic
to obscurely inequilateral, color in KOH date brown to blackish brown, in Melzer's
reddish tan, wall about 1 / thick.
Basidia 4-spored, 18-22 X 10-12 A, clavate from a broad short pedicel, hyaline
in KOH. Pleurocystidia scattered, 32-48 x 9-15 /, broadly fusoid-ventricose, apex
obtuse and neck short or finally somewhat elongated, wall thin, smooth, and
hyaline in KOH, cell content not distinctive in KOH or Melzer's. Cheilocystidia
abundant, mostly saccate and thin-walled, 30-38 x 9-15 /, some fusoid-ventricose
and measuring 32-40 X 9-14 A, when revived in KOH the hyphae from which they
originate are pale yellow in KOH. Caulocystidia resemble the cheilocystidia,
scattered, to rare.
Gill trama regular, the hyphal cells much inflated at maturity, pale brown to
nearly hyaline as revived in KOH, subhymenium cellular. Pileus trama of hyphae
vinaceous-brown when first revived in KOH but fading, darkest in young pilei.
Cuticle of pileus of loosely arranged vesiculose cells in a layer one cell deep, walls
yellowish to hyaline in KOH, smooth, thin, cell content not distinctive in KOH or
Melzer's. Clamp connections present. No distinctive reactions on any tissue as
mounted in Melzer's.
Type locality. Europe.
Habit and habitat. Solitary to scattered on organic debris.
Distribution. Colorado, Michigan, Montana, Ohio, Tennessee, Washington,
Wyoming.
Observations. Drosophila pellucidipes Romagn. is very close to my concept
of P. trepida but has a shining white stipe, paler more rapidly fading pileus, and
longer cystidia.
Material examined. Colorado: Smith 51663 (small spored variety). Michigan:
Foray 1948; Kauffman 6-12-07; Potter 5214; Smith 1947 (yr.), 25256, 25776,
25777. Montana: Kauffman 7-6-28; Mains 6107. Ohio: Walters 181. Tennessee: Hesler & Sharp 9194. Washington: Smith 14188, 14524, 14749, 14792,
29761, 29763, 30226. Wyoming: Smith 34618, 34649, 34823, 34828, 34830, 34867,
34974, 35203, 35275, 35538.
297. Psathyrella anaglaea (Maire) Smith & Hesler, Jour. Elisha Mitchell Soc.
62: 182. 1946.
Psathyra anaglaea Maire, Bull. Soc. Hist. Nat. Afr. Nord 22: 16. 1931.
Illust. Maire, 1. c. fig. 3. Smith & Hesler, 1. c. fig. 1; F, G, H, K. Text Fig. 639.
Pileus 7-15 mm broad, convex, hemispheric or finally somewhat expanded,