The North American species of Psathyrella.

264 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN [VOL. 24
weakly cinnamon-buff in KOH to nearly hyaline, smooth, cell content not distinctive. Hyphae of context in region of subcutis cocoa-color in KOH from pigment in the wall and incrusted on it, incrustations very fine and most conspicuous
on the narrow hyphae, the broad ones often smooth. Clamps rare to absent (one
seen on over 100 septa examined). No distinctive reaction on any tissue as
mounted in Melzer's.
Type locality. Ann Arbor, Michigan.
Habit and habitat. In pastures near but not on cow dung.
Distribution. Michigan.
Observations. In this species clamp-like branches are not infrequent on cells
of the stipe but often at places where there is no cross wall, so in ascertaining the
number of true clamps present one must be exceedingly careful. The degree of
color in the veil is probably not of great taxonomic value because it is so slight. In
many respects the species recalls P. obtusata but the spores at once distinguish it.
Material examined. Michigan: Potter 3306, 3558; Smith 20718, 20793 (Type).
223. Psathyrella odorata (Peck) Saccardo, Sylloge Fung. 5: 1136. 1887.
Agaricus odoratus Peck, Ann. Rep. N. Y. State Mus. 24: 70. 1872.
Illust. Text Figs. 509-511.
Pileus 2.5-5 cm broad, ovoid-convex, at length expanded, surface smooth,
hygrophanous, dark reddish brown and striatulate on the margin when moist,
when faded dingy white or clay-colored with a pinkish tint and somewhat atomate
and radiately rugose. Context thin, fragile, with a strong odor resembling that of
Sambucus pubens.
Lamellae crowded, broad, attached with a slight spurious decurrent tooth,
dingy flesh-colored then rosy brown, finally black with whitish edges.
Stipe 5-8 cm long, 2-4 mm thick, equal, hollow, base slightly enlarged, pallid,
slightly mealy and striate at the apex, subfibrillose when young.
Spores 13-15 x 6.5-8 j, smooth, apical pore present but small and apex not
obviously truncate, pore oblique in some spores, shape in face view oblong to
elliptic, in profile subelliptic to obscurely inequilateral, color in KOH dark date
brown becoming chocolate-gray-brown on standing, in Melzer's dark reddish
tawny, wall about 1 p thick (measured in KOH on broken spores).
Basidia 22-33x 10-14 I, 4-spored, hyaline in KOH, with a narrow pedicel.
Brachybasidioles not differentiated. Pleurocystidia scattered to abundant, 40 -70 x 9-18 a, broadly fusoid-ventricose with rounded apex to subcylindric or
elliptic-pedicellate and all with broadly rounded apex; wall smooth, thin and
hyaline; content not distinctive in KOH or Melzer's. Cheilocystidia similar to
pleurocystidia but shorter and varying to clavate or saccate, 24-42x 10-15 u.
Caulocystidia similar to cheilocystidia, readily collapsing.
Gill trama not reviving well but apparently regular, slightly brownish in KOH,
the color in the walls but fading on standing. Pileus having a cuticle of hyaline
thin-walled vesiculose cells several deep, the cell content not distinctive. Context
in region of subcuticular zone rusty brown in KOH but fading, with pigment
thickenings in the wall or slight incrustations (near the septa). Clamp connections present on hyphae of the stipe. No distinctive reaction on any tissue mounted
in Melzer's.
Type locality. West Albany, New York.
Habit and habitat. Around manure heaps, gregarious to subcespitose.
Distribution. New York.