The North American species of Psathyrella.

1972]

PSATHYRELLA

87

when faded, glabrous or with scattered fibrils at first, the margin appendiculate.
Context very fragile and thin, odor and taste not distinctive.
Lamellae crowded and narrow, adnate, seceding, white becoming purplish gray,
edges even but white.
Stipe 2-5 cm long, 2-3 mm thick, equal, hollow, fragile, white, base whitestrigose, with scattered fibrils above but soon glabrescent, apex pruinose.
Spores 6-7.5 x 3.5-4,u, smooth, apical pore present but inconspicuous, shape in
face view elliptic to subovate, in profile subelliptic to obscurely inequilateral, color
in KOH cocoa-color slowly becoming chocolate-gray or darker, in Melzer's reddish
tawny, wall about 0.2 pu thick.
Basidia small, 14-16x7-8 a, 4-spored, hyaline in KOH. Brachybasidioles
present, 8-10 ft broad. Pleurocystidia none. Cheilocystidia 32-46x 9-14 a, utriform to fusoid-ventricose with broadly rounded apex, some merely clavate, thinwalled, hyaline, smooth, content not distinctive. Caulocystidia clavate to utriform
or fusoid-ventricose, mostly like the cheilocystidia but often larger. Gill trama
of greatly enlarged hyaline cells (40-90 x 10-20 /), subhymenium cellular but the
cells only 8-12 u wide. Pileus with a cuticle of vesiculose cells one or two deep,
walls thin, hyaline and smooth, content not distinctive. Hyphae of context with
hyaline, smooth walls in KOH, in Melzer's no distinctive reactions noted. Clamps
present.
Type locality. Green Island, New York.
Habit and habitat. Gregarious to subcespitose or scattered on damp soil with
much lignicolous debris in it, or near stumps of hardwoods; late spring and
summer.
Distribution. Alabama, California, Idaho, Michigan, New York, North Carolina, Ohio, Oregon, Pennsylvania, Tennessee, Utah, Vermont, Washington in the
United States and Nova Scotia in Canada.
Observations. Since some European authors recognize P. coronata as having
spores 7-10 M long, it seems best to return to the American name which clearly
applies to the species described here. Many reports in the literature for "Hypholoma incertum" apply to P. candolleana. In spite of this Peck's species is to
be regarded as common and widely distributed in North America. Peck noted
a tendency for at least a partial annulus to form, and this is a feature, rarely, of
Michigan collections, but see P. diabolica also. Hypholoma incertum var. sylvestre
Kauffman (Agar. Mich. p. 264), is incompletely described and the specimens
are in very poor condition. It is best to drop the name. Also see var. pygmea,
p. 429.
Material examined. UNITED STATES. Alabama: Burke AU, AZ, BN,
BNb. California: Morse 11-16-37. Idaho: Smith 64938. Michigan: Homola
800, 812; Hoseney 5, 613; Kanouse 6-26-31; Kauffman 8-14-25; Lange 1429,
1441; Potter 3307, 3889, 4653, 4681, 4682, 5246, 5399, 5402, 5416, 5525, 5526, 6473,
6477, 7576, 7577, 9622; Smith 6555, 25479, 25480, 25481, 25483, 25785, 32101,
32392, 32643, 36482, 57127, 63598, 64825, 66721, 71529, 73013, 75412, 7-19-38,
6-?-62. New York: Peck's type. North Carolina: Kauffman 8-15-24. Ohio:
Cooke 33336. Oregon: Gruber 619. Pennsylvania: Kelly 502; Sumstine 26A.
Tennessee: Hesler 3704, 20177, 20442; Sharpe and Underwood 3701, 4477. Utah:
McKnight F83. Vermont: Shaffer 2994, 3017. Washington: Flett 6-26-41; Smith
16612, 47923. CANADA. Nova Scotia: Smith 646; Wehmeyer 592.
49. Psathyrella rogueiana A. H. Smith, sp. nov.
Pileus 4-6 cm latus, convexus demum late convexus umbrino-melleus vel
melleus, sparse fibrillosus demum glaber (fibrae pallide alutaceae), ad marginem