The North American species of Psathyrella.

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MEMOIRS OF THE NEW YORK BOTANICAL GARDEN

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Lamellae close, broad, adnate, seceding, pallid brownish becoming tawny and
in oldest wood brown (gray-brown), edges even.
Stipe 3-5 cm long, 4-7 mm thick, equal, firm, whitish throughout, apex striate
from gill impressions, lower down fibrillose to squamulose with buff-colored veil
fibrils, veil leaving a zone of fibrils when it breaks but the zone soon evanescent,
no sign of the base darkening in oldest basidiocarps seen.
Spores 7-8.5 x 4-4.5 pu, smooth, apical pore very inconspicuous to lacking, shape
in profile mostly obscurely to somewhat bean-shaped, in face view oblong to elliptic, color in KOH a dingy pale ochraceous-cinnamon, in Melzer's pale reddish
tawny (or broken spores often dark bay-red).
Basidia 4-spored, narrowly clavate, 22-27 x 5-7 pt. Pleurocystidia scattered to
abundant, 28-37x 8-14 A, clavate-mucronate to merely clavate, the apical protuberance up to 10 /, long and 3 tu wide, wall thin and smooth, content of cell not
distinctive in either KOH or Melzer's. Cheilocystidia clavate to (rarely) clavatemucronate, 24-36x8-13 /, content of some cells ochraceous in KOH. Caulocystidia present as elongate-clavate hyphal ends.
Pileus cuticle a layer of vesiculose cells 2-3 deep, the walls about 0.5 pU thick
and rusty ochraceous in KOH but paler on standing; subcutis rusty yellow-brown
in KOH but soon fading. Context hyphae hyaline as revived in KOH and of
inflated cells. Clamps present. No amyloid reactions on any tissue and no other
distinctive reactions present.
Type locality. McCall, Idaho.
Habit and habitat. Cespitose on outwash of a stream, July.
Distribution. Idaho.
Observations. The distinguishing features of this species are the colored cell
walls of the cuticular hyphae of the pileus and their thickness (up to 0.5 p), the
pleurocystidia with the shape of typical chrysocystidia but not distinctive as to
content, and the color of the spores in KOH-which is strongly reminiscent of
those of section Homophron. A spore deposit was not obtained, but the gills of
dried specimens have a decided red tinge which has been accentuated, apparently
by the naphthalene used as an insect repellent.
348. Psathyrella multipedata (Peck) A. H. Smith, Contr. Univ. Mich. Herb. 5:
33. 1941.
Psathyra multipedata Peck, Bull. Torrey Club 32: 80. 1905.
Atylospora multipedata (Pk.) Murrill, Mycologia 14: 265. 1922.
Psathyra stipatiseima Lange, Medd. Foren. Svamp. Fremme 3: 1. 1922-25.
Illust. P1. 85; P1. 86, fig. c; Text Figs. 784-786.
Pileus 1-4.5 cm broad, ovoid to obtusely conic, becoming broadly umbonate,
convex or nearly plane, surface glabrous, very young buttons with a thin zone of
white evanescent fibrils along the margin, surface smooth or at times rugulose,
hygrophanous, "buckthorn brown" over all and with a faintly striate margin when
moist, varying to cocoa-color, lubricous, fading to whitish, sometimes dull lead
gray along the margin and more or less ochraceous-buff on the disc. Context thin
and fragile, pallid, odor and taste not distinctive.
Lamellae close, narrow (about 3 mm wide), ascending adnate, whitish, soon
sordid purplish brown, edges even and white-fimbriate.
Stipe 5-10 cm long, 2-4 mm thick, equal, hollow, very rigid and fragile, densely
cespitose, the clusters branching from the apex of a long pseudorhiza which arises
from a depth of a foot or more under the ground, veil remnants slight and either