The North American species of Psathyrella.

1972]

PSATHYRELLA

415

28-37 x 9-12 t, fusoid-ventricose with obtuse apex, hyaline, smooth, thin-walled.
Caulocystidia scattered to rare, vesiculose to clavate, 9-15 p broad, thin-walled
but wall yellowish in KOH in some.
Pileus cuticle a layer of vesiculose cells 2-4 deep, the walls thin but brownish
in KOH, walls smooth. Subcuticular region of hyphae vinaceous-brown in KOH
and with roughened walls. Clamps present. No distinctive reactions in Melzer's.
Type locality. Payette Lakes, Valley County, Idaho.
Habit and habitat. Gregarious on soil along a road.
Distribution. Idaho.
Observations. The dark colors, reflected also in the color of the walls of the
cuticular hyphae, the stature of P. obtusata, and the darkening stipe are the most
significant features. On the whole it is a very ordinary appearing Psathyrella.
Material examined. Idaho: Smith 64951 (Type).
392. Psathyrella limicola (Peck) A. H. Smith, comb. nov.
Agaricus limicola Peck, Rep. N. Y. State Mus. 24: 70. 1872.
Psilocybe limicola (Pk.) Saccardo, Sylloge Fung. 5: 1054. 1887.
var. limicola
Illust. Text Figs. 836, 837, 839.
Pileus 1-2.5 cm broad, convex becoming nearly plane, surface glabrous,
hygrophanous, dark brown and striatulate on the margin when moist, pale
ochraceous-brown and rugose when dry. Context thin and fragile.
Lamellae crowded, rounded next to the stipe and adnexed, cinnamon-brown,
darker when old.
Stipe 3-8 cm long, 1.5-3 mm thick, slender, equal, brittle, silky, hollow, stuffed
in the lower portion, whitish.
Spores 8-10.5 x 4.5-5 u, smooth, apical pore present and apex truncate under
low-power oil immersion, shape in face view elliptic to slightly ovate, in profile
elliptic to obscurely inequilateral, color in KOH date brown slowly darkening to
chocolate-brown or darker date brown, in Melzer's reddish tawny, wall about
0.5 A thick.
Basidia 4-spored, 18-22 x 8-10 t, subellipsoid, hyaline in KOH. Pleurocystidia
38-54 x 10-15 t, fusoid-ventricose with obtuse apex, wall thin, smooth and hyaline,
cell content not distinctive in KOH or Melzer's. Cheilocystidia similar to the
pleurocystidia but not as long. Caulocystidia not distinctive, the only ones seen
were merely clavate end cells of hyphae and these 9-14 t wide.
Cuticle of pileus of vesiculose cells 1-2 cells deep, their walls hyaline to
yellowish in KOH, thin and smooth, cell content not distinctive. Clamps present.
Type locality. Greig, New York.
Habit and habitat. Gregarious to cespitose on wet muck soil in woods.
Distribution. Michigan, New York, Wyoming.
Observations. The pale color of the pileus, generally cinnamon brown lamellae,
whitish stipe, medium-sized spores, habitat, and lack of distinctive caulocystidia
characterize this species.
Material examined. Michigan: Kanouse & McCrea 523; Potter 4442, 4552;
Smith 20298, 20301, 20314, 20320, 20323, 20919, 21373, 22071, 25348, 25627, 25793,
26012, 33751. New York: Peck's Type. Wyoming: Smith 34547.