The North American species of Psathyrella.

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MEMOIRS OF THE NEW YORK BOTANICAL GARDEN

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Cuticle of pileus of vesiculose cells several deep and from them and from
between them arise filaments 9-13 K wide with walls both roughened and tawny
in KOH, walls of cuticle cells somewhat roughened and paler in color in KOH;
subeuticle of hyphae sparsely roughened and pale buff in KOH; in Melzer's the
roughness on all hyphae very inconspicuous. Clamps regularly present.
Type locality. France.
Habit and habitat. Scattered, gregarious to cespitose on rich moist humus or
soil, on compost heaps, very old sawdust piles, or areas rich in organic material.
It is fairly common during wet weather.
Distribution. California, Idaho, Illinois, Kansas, Maryland, Michigan, Minnesota, New Jersey, New Mexico, New York, Ohio, Oregon, Pennsylvania, Tennessee.
Observations. This is an edible species, in fact Kiihner and Romagnesi (1953)
give it two stars, indicating that it is better than average. The spores of this
species are usually figured as verrucose with the warts forming an irregular outline as the spores are viewed in optical section. In most of the American collections a hyaline envelope covers the spore and gives a smooth outline in optical
section-especially if the envelope is pigmented slightly. This envelope does not
always revive well when ammonia is used as a mounting medium and under these
circumstances the spore indeed does appear verrucose in the usual meaning of
the term.
The American material I have seen apparently has a heavier veil and often
larger basidiocarps than is typical for the species in Europe. This point deserves
further critical study.
Material examined. California: Smith 3750, 3865. Idaho: Smith 68303,
70122, 73923. Illinois: Harding 6-2-47. Kansas: Haard 444. Maryland: Kauffman 7-1-18; Kelly 33, 101. Michigan: Baxter 7-21-20; Brooks 1881; Homola
934; Hoseney 431, 706; Kauffman 7-21-12; Kanouse 10-14-54; Lee 7-19-07;
McVaugh 8-19-66; Mains Oct.-Nov. 1938, 6-?-40; Mazzer 3753, 4079, 4366;
Smith 32-438, 33-1027, 33-1054, 35, 1490, 1537, 5030, 7563, 7672, 18676, 18865,
20571, 43438, 57897, 62351, 62891, 64055, 66377, 66379, 67568, 72627, 72808, 72952,
73145, 78277; Thiers 4134. Minnesota: Weaver 1631. New Jersey: Doak 8-6-32.
New Mexico: Barrows 1589, 8-?-55. New York: Rogers 2116; Seaver 5-?-37.
Ohio: Cooke 10-?-55; Kelsey 1067; Walters 163, 218. Oregon: Smith 28046.
Pennsylvania: Henry 4447. Tennessee: Hesler 10882, 18010; Sharp 11495, 14697.
5a. Psathyrella velutina var. boughtoni (Peck) A. H. Smith, comb. nov.
Hypholoma boughtoni Peck, Bull. N. Y. State Mus. 139: 23. 1910.
Illust. 1. c. pl. 2, figs. 1-7.
Pileus 2.5-7 cm broad, broadly convex or subhemispheric, rarely with an
umbo, glabrous or slightly fibrillose, often cracked concentrically or areolately,
pale reddish brown or grayish brown. Context whitish, taste disagreeable.
Lamellae moderately close, adnate, purplish brown to seal brown or blackish,
obscurely spotted, whitish on the edges.
Stipe 2.5-6 cm long, 4-10 mm thick, equal, floccosely fibrillose, striate above,
hollow, white or whitish.
Spores 8-11x5-7 u, elliptic in face view excluding the snout-like apex, in
profile broadly somewhat inequilateral, apex truncate, color in KOH soon dark
chocolate-brown, in Melzer's reddish (bay-red), surface minutely verrucose as
in var. velutina, wall about 0.5 / thick.
Basidia 23-28x9-10 a, 4-spored, hyaline in KOH, clavate. Pleurocystidia