The North American species of Psathyrella.

1972]

PSATHYRELLA

i97

"snout," color in KOH dark bister to blackish brown ("mummy brown"), in
Melzer's dark reddish tawny, wall about 1 thick.
Basidia 2-spored, 17-22x9-14 A, clavate, hyaline in KOH. Pleurocystidia
scattered, 36-44(-50) x9-14,A, fusoid-ventricose with acute apex, wall thin,
smooth and hyaline, cell content not distinctive in KOH or Melzer's. Cheilocystidia similar to pleurocystidia but smaller. Caulocystidia 35-70x10-18 /u,
mostly clavate but varying to fusoid-ventricose with obtuse apex, smooth, thinwalled, hyaline in KOH.
Gill trama hyaline to pale sordid brownish in KOH, the cells greatly enlarged
and more or less regularly arranged. Pileus trama also of greatly enlarged cells
and nearly hyaline in KOH; cuticle formed of upright clavate to ellipsoid or
globose cells arranged in more or less of a palisade, the cells hyaline, thin-walled,
smooth and lacking distinctive content in KOH or Melzer's. Veil hyphae yellowish in KOH and some of the end cells with slightly thickened refractive walls.
Clamp connections present.
Type locality. Wolf's Bog, Cheboygan County, Michigan.
Habit and habitat. Scattered on black muck.
Distribution. Michigan and Oregon.
Observations. The color change to yellow in KOH of the veil hyphae and the
tendency for the end cells to have thickened refractive walls, the large spores, and
generally shorter pleurocystidia than P. gracilis distinguish this species along with
the habitat.
Material examined. Michigan: Smith 33-611, 22041 (Type), 74613; Oregon:
Smith 19338.
155. Psathyrella victori A. H. Smith, sp. nov.
Pileus 1.5-4 cm latus, late conicus demum convexus, floccoso-squamulosus,
glabrescens, fulvus dein sordide fulvidulus; lamellae confertae, perangustae, adnatae, brunneolae, demum subfulvae; stipes 4-8 cm long, 2-5 mm crassus, albidus,
floccose squamulosus, glabrescens, deorsum demum sordide fulvae; sporae 8-11 x
5-6 L; pleurocystidia 34-46 x 8-13 I, fusoide ventricosa; fibulae adsunt. Typus.
Potter 10560 (MICH); legit prope Ithaca, Michigan.
Pileus 1.5-4 cm broad, obtuse, expanding to broadly conic or finally convex
with a decurved margin, surface at first covered with white appressed flocci,
glabrescent, margin not appendiculate, color rusty brown and fading to dingy
tawny, hygrophanous, dingy tawny as dried. Context thin and fragile.
Lamellae close to crowded, very narrow, ascending adnate, brownish when
young, then with a rusty tan tone and as dried cocoa-brown; edges even.
Stipe 4-8 cm long, 2-5 mm thick, at times more or less connate at the base,
hollow, fragile, white at first and with patches of whitish veil remnants, tan in age
beneath the fibrils (or when dried), base mycelioid to strigose, arising from buried
wood but lacking a pseudorhiza.
Spores 8-11 x 5-6 a/, smooth, truncate from an apical pore or apex only
obscurely truncate, shape in face view ovate to elliptic, in profile, subelliptic or
ovate or obscurely inequilateral, color in KOH dull chocolate-color to chocolategray and then pallid grayish with a tinge of ocher; in Melzer's dull tawny, wall
about 0.4 p thick.
Basidia 4-spored, clavate, 7-9 u wide, 18-25 A long. Pleurocystidia scattered,
34-46x8-13 a, fusoid-ventricose, the neck often flexuous and apex subacute,