The North American species of Psathyrella.

1972]

PSATHYRELLA

55

smooth walls (revived in KOH), content not distinctive in either KOH or
Melzer's. Hyphae of the subcutis and trama hyaline as revived in KOH and
lacking distinctive content. Clamp connections present.
Type locality. Alcove, New York.
Habit and habitat. Clustered on or near hardwood stumps, late summer and
fall.
Distribution. Maryland, Michigan, New York, North Carolina, Ohio, Pennsylvania, Tennessee.
Observations. This variant differs from var. lacrymabunda in having pleurocystidia with very slight amyloid reaction or none at all, and in which the content
of the cell when revived in KOH remains hyaline or practically so. The spores are
a shade smaller, but hardly significantly so. However, the outer veil is more
distinctly colored, which should aid in distinguishing var. aggregata in the fresh
condition.
Material examined. Maryland: Kelly 1675. Michigan: Kauffman 8-27-05;
Mains 10-9-32; Pennington 8-7-06; Smith 64406, 72038, 78137. New York:
Peck's type; North Carolina: Hesler 12309, 17149; Smith 7413, 7538. Ohio:
Walters 223; Worthington no number. Pennsylvania: Kauffman 9-8-26;
Sumstine 1. Tennessee: Hesler 18281.
20. Psathyrella alboalutacea A. H. Smith, Mycologia 42: 118. 1950.
Illust. 1. c. fig. 3, g, h; 16a b; 17. P1. 12; P1. 13, fig. a; Text Figs. 46-48, 50.
Pileus (2-)3-5(-6) cm broad, obtuse to convex at first, becoming plane or
nearly so, the disc in some elevated as a low broad umbo, surface dry and
fibrillose, the fibrils innate and forming an appressed cottony mat over the buttons
which are pure white, the fibrils soon become aggregated into patches and discolor to avellaneous or wood brown, the disc at times dingy alutaceous, at maturity
entire surface off-color toward cinnamon-buff or disc more brownish (near
cinnamon-brown), margin fibrillose-appendiculate to cottony-appendiculate at
first but finally nearly naked. Context firm and hard for this genus, hygrophanous,
watery avellaneous fading to whitish, odor faintly fragrant but soon fading, taste
not distinctive.
Lamellae depressed-adnate, seceding, close, narrow to moderately broad, white
to very pale avellaneous becoming drab-gray to hair brown, edges white-floccose.
Stipe 3-5 cm long, 10-12 mm thick, firm and hard, stuffed but becoming
hollow, white within but pinkish to orange-pink in the base, with dingy fibrils over
lower half in some, in others white-fibrillose, upper half white and longitudinally
striate.
Spores purple-brown in deposit (near "benzo brown"), 7.5-9 x 4-4.5 a, smooth,
apical pore not evident, shape in face view ovate to elliptic, in profile bean-shaped
to obscurely inequilateral color in KOH cocoa-color, becoming only slightly
darker, in Melzer's bay-brown, wall about 0.2 K thick.
Basidia 4-spored, 26-34x 5.5-7 a, narrowly clavate, hyaline in KOH, a few
with refractive particles. Pleurocystidia of two types: (1) Clavate to subvesiculose-pedicellate, 25-40 x 10-14 a, thin-walled, smooth, hyaline in KOH and
content not amyloid; (2) fusoid, 40-53x9-14 [, thin-walled, hyaline in KOH,
smooth, apex obtuse to subacute, varying to mucronate, cell content not amyloid
but when fresh often containing numerous small globules. Cheilocystidia clavate
to fusoid but apex not pointed, 32-48x9-15 A, hyaline and smooth, content
homogeneous and not amyloid. Caulocystidia elongate-clavate, 30-70x 10-18 a,
not abundant.