The North American species of Psathyrella.

1972]

PSATHYRELLA

75

35a. Psathyrella ellenae var. yubaensis Thiers & A. H. Smith, var. nov.
Sporae 8-10 x 4-5 u; pleurocystidia 44-68 (-80) x 10-18 (-20) I, ad apicerum
obtusa, saepe crassotunicata (0.5 A). Typus. Thiers 13870 (MICH); legit prope
Yuba Pass, Sierra County, California.
Pileus 3-4 cm broad, convex expanding to broadly convex or plane, in age some
slightly umbonate and with undulating margin, glabrous, distinctly rugulose over
entire marginal portion, smooth on the disc, when partly faded the marginal area
chestnut-brown, the central portion warm buff to pale olive-buff; margin incurved
and entire at first but becoming eroded, naked at all times. Context very fragile,
about 3 mm thick in the disc, concolorous with the surface, taste and odor not
distinctive.
Lamellae close to subdistant, several tiers of lamellulae, thin, fragile, narrow,
adnate, avellaneous, dark vinaceous-brown as dried; margin becoming eroded,
paler in color than the faces.
Stipe 3-4 cm long, 3-6 mm thick near apex, hollow, white, shiny, surface
appressed silky-fibrillose, dry, with a conspicuous persistent subapical annulus;
interior of stipe white and unchanging.
Spores 8-10 x 4-5 /, smooth, apical pore distinct and apex truncate as seen in
optical section, shape in face view ovate to subelliptic, in profile somewhat to
obscurely inequilateral, color in KOH dingy ochraceous-tawny slowly becoming
grayish tinged, in Melzer's bright pale tawny, wall about 0.3 U thick.
Basidia 4-spored. Pleurocystidia 44-68 (-80) x 10-18 (-20) /, fusoid-ventricose
with obtuse smooth apex; walls often slightly thickened and yellowish in KOH,
smooth; cell content not distinctive. Cheilocystidia abundant, clavate, hyaline,
26-40 x 8-15 u, thin-walled, hyaline in KOH.
Pileus cuticle 2-5 cells deep, the cells hyaline to yellowish in KOH, some very
large cells present, walls somewhat thickened (up to 0.5,) but smooth. Hyphae
of the subcuticular region nearly hyaline in KOH. Clamps present.
Type locality. Yuba Pass, California.
Habit and habitat. Gregarious in conifer woods on humus.
Distribution. Known only from the type locality.
Observations. This variety differs from the type variety in having obtuse
pleurocystidia, somewhat thickened refractive cell walls in the cuticular hyphae,
and paler spores in KOH.
36. Psathyrella longistriata (Murrill) A. H. Smith, Mushrooms in Their Natural
Habitats, 552. 1949.
Stropharia longistriata Murrill, Mycologia 4: 301. 1912.
Stropharia fragilis Kauffman, Pap. Mich. Acad. Sci. 5: 144. 1926.
Illust. Kauffman, 1. c. pl. 12. P1. 20; P1. 21; Text Figs. 105-109.
Pileus (3-)4-8(-10) cm broad, obtusely conic to convex when young and the
margin incurved, expanding to plane or broadly convex but sometimes with a
low broad umbo, surface at first covered with thin fibrillose patches of veil
remnants or merely thinly fibrillose, soon glabrous, smooth but sometimes becoming rugulose at least around the disc, moist, decidedly hygrophanous, when moist
dark avellaneous, pale sordid yellowish brown, to dark rusty brown or dark reddish
brown (cinnamon-buff, "wood brown" "Mars brown" or "Mikado brown"), more
or less translucent striate when moist, fading to pallid or tinged cinnamon buff
or merely pallid ("tilleul buff" to "cinnamon-buff"). Context very thin and