The North American species of Psathyrella.

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MEMOIRS OF THE NEW YORK BOTANICAL GARDEN

[VOL. 24

Distribution. Known only from the type locality.
Observations. The material in the Ellis collection is not the same as the type
(Bartholomew 2199, July 20, 1896). The pallid pileus when young, presence of
brachybasidioles in the hymenium, and the slight differentiation between the
cuticular and tramal hyphal cells are distinctive. The cuticle of the pileus is about
2 cells deep. Psathyrella badiophylla Romagn. is close to this species.
237. Psathyrella bartholomaei Peck, Bull. Torrey Club 22: 490. 1895.
Illust. Text Fig. 534B.
Pileus 1.5-3 cm broad, subconic or convex, surface glabrous, striate on the
margin, pale brown. Context thin and fragile.
Lamellae close, nearly plane, adnate, brownish becoming black.
Stipe 2.5-4 cm long, scarcely 2 mm thick, slender, flexuous, hollow, adorned
with a few grayish fibrils, pale brown.
Spores 9-12x5-6 I, smooth, apical pore well developed and apex of spore
truncate, shape in face view ovate to elliptic, in profile obscurely inequilateral to
subelliptic, wall about 1 /u thick, color in KOH blackish brown, in Melzer's dull
bay-red.
Basidia 4-spored, 9-12 / broad at apex, 20-26 p long, clavate, hyaline in KOH.
Brachybasidioles present at maturity. Pleurocystidia not found (type material
did not revive well). Cheilocystidia 28-33 X9-12(-15) i, vesiculose, clavate or
broadly fusoid-ventricose with rounded apex, hyaline, thin-walled, smooth.
Gill trama not reviving well, tawny in KOH. Pileus trama of tawny-brown
hyphae with incrusted patches of pigment on the walls (dark vinaceous-brown in
Michigan collections). Cuticle of pileus of vesiculose hyaline cells with a mucilaginous thickening lining the interior wall causing it to appear thickened in the
manner of a Rhizopogon basidium, color pale cinnamon to nearly hyaline in KOH.
Clamp connections present but difficult to demonstrate in the type.
Type locality. Rockport, Kansas.
Habit and habitat. On wet ground in woods, also on green humus.
Distribution. Kansas, Michigan (?)
Observations. The material lining the interior of the cuticular cells may not
be a "good" taxonomic feature-the details of the preservation of the specimen
are not known. This material does not show in all cells or in all collections. The
lack of pleurocystidia, presence of brachybasidioles, blackish spores in KOH, the
well-developed apical pore of the spores, and the brown color in KOH of the
subcuticular zone or hyphae of the pileus context when revived are distinctive.
Material examined. Kansas: (Peck's type). Michigan: Sass 10-2-27.
238. Psathyrella agrestis A. H. Smith, sp. nov.
Pileus 1-3 cm latus, convexus, glaber vel ad marginem sparse albo-flocculosa,
glabrescens, fusco-brunneus; lamellae latae (~5 mm), pallidae demum cinereae
vel fusco-brunneae; stipes 3-5 cm longus, 1.5-3 mm crassus, albidus, deorsum
sparse floccosus, glabrescens; sporae (8-)9-11x5-6(-7) u; pleurocystidia nulla;
fibulae adsunt. Typus. Smith 10921 (MICH); legit prope Ann Arbor, Michigan.
Illust. P1. 74, fig. b; Text Figs. 534C, 535.
Pileus 1-3 cm broad, convex, becoming broadly convex but not plane, glabrous
except for concentric white patches of fibrils from the thin veil along the margin
on immature pilei, surface radially wrinkled or somewhat netted at times near the