The North American species of Psathyrella.

1972]

PSATHYRELLA

157

fibrils especially toward the appendiculate margin, glabrescent, color dark rusty
to reddish brown when moist, ("Mars brown" to "Vandyke brown"), watery in
appearance but fading slowly to sordid tan (more or less hygrophanus), margin
zonate at times, surface conspicuously radially rugulose. Context fragile but
thick and watery brown, odor and taste mild.
Lamellae close, moderately broad, bluntly adnate, concolorous with the pileus,
very thin and fragile, near "bone brown" (very dark vinaceous-brown) when dried.
Stipe 6-10 cm long, (5-) 10-15 mm thick, equal, hollow, whitish, white fibrillose
over the lower portion, apex silky-pruinose.
Spores 6.5-8(-9) x 4.5-5.5,/, smooth, apical pore present but not conspicuous,
shape in face view ovate, in profile obscurely inequilateral to obscurely beanshaped, color in KOH dark cocoa-color slowly becoming dark chocolate-color, in
Melzer's dark bay-red, wall about 0.3-0.4, thick.
Basidia 4-spored, 20-26 x 6-9,u, narrowly clavate, hyaline in KOH. Pleurocystidia abundant, 45-68x 10-22 ~, broadly ventricose above a broad base and
apex a finger-like projection or mucro 2-3.5 I broad, walls hyaline smooth and
thin, with a large hyaline globule in KOH, the globule yellowish in Melzer's.
Cheilocystidia similar to pleurocystidia or smaller and clavate-mucronate (26 -40x 7-14 4), bases often yellowish brown in KOH (the whole gill edge colored
in robust specimens). Caulocystidia similar to pleurocystidia but larger, containing the same kind of globule.
Gill trama parallel, the hyphae 8-15, wide, hyaline to pale vinaceous-brown
when revived in KOH. Pileus with a cuticle of inflated cells but elongated
perpendicularly to the pileus surface in an irregular palisade, cell walls smooth,
thin and hyaline, content not distinctive. Hyphae of the context tawny-brown
in KOH but fading on standing. Clamp connections present. Pileocystidia similar
to the pleurocystidia, scattered.
Type locality. Port Jefferson, New York.
Habit and habitat. On humus or decayed wood, scattered to gregarious.
Distribution. Alabama, Massachusets, Michigan, New York, North Carolina,
Ohio, Oregon, Pennsylvania, Tennessee, West Virginia.
Observations. Kent McKnight has found a bitter variant of this species. It
is not included in the distributional records as further studies are desirable in
regard to its identity.
Some spiral brown incrustations were found to be present on the hyphae of
the subcuticular region of the pileus in some collections. When fruiting luxuriantly the pilei of this species are very often conspicuously rugose-reticulate.
Material examined. Alabama: Burke BE. Massachusetts: Smith 67257.
Michigan: Ammirati 3438; Kanouse 629; Smith 28743, 36490, 75293, 75557,
77573. New York: Peck's type. North Carolina: Hesler 16378. Ohio: Walters
136, 146, 185. Oregon: Smith 24238; Thiers 750. Pennsylvania: Kauffman
9-6 and 7-24, 9-12-24, 8-30-26. Tennessee: Hesler 17202. Virginia: Murrill
9-15-26.
113. Psathyrella oregonensis A. H. Smith, sp. nov.
Pileus 2.5 —5 cm latus, obtuse conicus demum plano-umbonatus, glaber, ad
marginem appendiculatus, umbrino-melleus; lamellae angustae, adnatae, pallidae,
demum griseofuscae; stipes 4-6 cm longus, 3-5 mm crassus, pallidus, glaber;
sporae 8-10 x 4.5-5.5x5.5-6.5 i; pleurocystidia 48-62 x10-16 f, ad apicerum
obtusa vel subcapitata; fibulae adsunt. Typus. Smith 28182 (MICH); legit in
Mt. Hood National Forest, Oregon prope Beaver Creek.