The North American species of Psathyrella.

1972]

PSATHYRELLA

183

cuticle of vesiculose cells 2-3 deep, walls thin, smooth and hyaline, cell content
not distinctive in KOH or Melzer's. Veil remnants of hyphae 6-12 p wide and
hyaline in KOH. Hyphae of context hyaline to pale brownish in KOH, walls thin
and smooth. Clamp connections present. No distinctive reactions noted on any
tissue as revived in Melzer's.
Type locality. Mt. Hood, Oregon.
Habit and habitat. Scattered on debris in rich soil under alder and cottonwood.
Distribution. Idaho, Michigan, Oregon and Washington. Also in Europe.
Observations. This is a common and characteristic species of the Pacific
Northwest. It is curious that it seems most closely associated with two Cuban
species.
Material examined. Idaho: Smith 47273, 69088, 73538, 76977. Michigan:
Smith 34087, 34090, 35979. Oregon: Smith 19168, 19693, 19694, 19763, 23790,
23872, 24455, 24648, 26696. Washington: Smith 3000, 13175, 17339, 17340, 17341,
30423, 47458, 47900.
Stirps Typhae
Sect. Typhicolae (of Drosophila), Romagn., Bull. Soc. Linn. Lyon 31: 51. 1944.
Psathyrella sect. Typhicolae (Romagn.) Singer, Sydowia 15: 67. 1961.
Key to Species of Stirps Typhae
1. Veil pale tan to buff; spores nearly hyaline in KOH. 140. P. typhae.
1. Veil white to grayish; spores cocoa-color or darker in KOH (nearly hyaline in
P. subaustralis). 2
2. Lamellae cinereous becoming black. 141. P. comata.
2. Lamellae whitish becoming cocoa-color and finally argillaceous to dark
reddish brown. 3
3. Spores 12.5-15 X 6.5-8 u; brachybasidioles present. 142. P. delicatella.
3. Not with either of above features. 4
4. Spores nearly hyaline in KOH; spores 6-7.5 t, wide. 143. P. subaustralis.
4. Spores bister or darker in KOH and 5-6 A wide. 144. P. lanuginosa.
140. Psathyrella typhae (Kalchbrenner) Pearson & Dennis, Trans. Brit. Mycol.
Soc. 31:185. 1948.
Agaricus typhae Kalchbrenner, Gomb. 206. 1865.
Psathyra typhae (Kalchbr.) Saccardo, Syll. Fung. 5: 1067. 1887.
Naucoria scirpicola Peck, Rep. N. Y. State Mus. 42: 19. 1889.
Illust. Peck, 1. c. pl. 2, figs. 6-10. P1. 60, fig. d; Text Figs. 313-314.
Pileus 5-20 mm broad, convex, becoming nearly plane, at very first covered
with thin patches of pale tan fibrils, soon glabrous, dark to pale rusty brown
("russet" to "cinnamon-brown" or "Sayal brown"), hygrophanous, fading to pale
buff, pellucid-striate when moist, somewhat plicate when faded. Context very
fragile, thin and watery, odor and taste not recorded.
Lamellae subdistant to moderately close, broad, attached by a narrow tooth
or nearly free, pallid to whitish at first, soon pale brown, finally with a tinge of
purplish brown.
Stipe 1-2 cm long, 1-1.5 mm thick, hyaline, very weak, watery, fragile, covered
by scattered fibrils or with a denser fibrillose zone toward the base, the base
slightly enlarged and delicately mycelioid at the point of attachment.
Spores 10-12x 5-6.5 p,, smooth, apical pore not evident because of the thin
wall, shape in face view elliptic to ovate, in profile obscurely inequilateral to (in