The North American species of Psathyrella.

1972]

PSATHYRELLA

143

Type locality. Highlands, North Carolina, 4000 ft. elev.
Habit and habitat. Gregarious on deep humus in frondose woods, September.
Distribution. Known only from the type locality.
Observations. This species is close to P. kauffmanii var. exannulata, but is a
richer color when young, the spores are wider and take a reddish tinge in KOH,
and the gills are white at first. It has the colors of P. delineata or P. hydrophila
when these are fully pigmented.
97. Psathyrella subradicata A. H. Smith, sp. nov.
Pileus 1-3 cm latus, obtuse conicus, demum late convexus, glaber, ad marginem
appendiculatus, sordide pallido-cinnamomeus; lamellae confertae, latae, brunneolae demum umbrino-vinaceae; stipes 2-4.5 cm longus, 1.5-3 mm crassus,
subradicatus, albidus, glaber; sporae 7-9 x 4-5 A; pleurocystidia 38-50 x 9-15 /,
versiformia (utriformia, fusoide ventricosa et pedicellato-elliptica); fibulae adsunt. Typus. Trueblood 2945 (MICH); legit Boulder Creek, Owyhee County,
Idaho.
Illust. Text Figs. 239-241.
Pileus 1-3 cm broad, obtusely conic expanding to broadly convex but retaining
an obtusely conic umbo, surface glabrous except for the margin which is at first
appendiculate with patches of the pallid veil, veil remnants soon evanescent,
pale dingy cinnamon-brown fading to pallid, surface even or nearly so. Context
thin, fragile, concolorous with surface either moist or faded, odor earthy, taste
not distinctive.
Lamellae close, moderately broad, adnate-seceding, brownish when young,
nearly "bone brown" (dark vinaceous-brown) as dried, edges even.
Stipe 2-4.5 cm long, 1.5-3 mm thick, more or less radicating (base with
adhering dirt over a short pseudorhiza for 1-1.5 cm additional length), nearly
equal above the ground line, white (pallid as dried, over all), naked or at first with
scanty evanescent veil particles.
Spores fuscous-brown in deposit, 7-9 x 4-5 a, smooth, apical pore distinct and
apex truncate to indistinctly so, shape in face view elliptic to suboblong, rarely
ovate, in profile obscurely inequilateral to obscurely bean-shaped, color in KOH
dark cocoa-color soon becoming a medium dark chocolate-color, in Melzer's
reddish tawny, wall about 0.2, thick.
Basidia 4-spored, 18-24 x 7-9, clavate, hyaline in KOH. Pleurocystidia
38-50 x 9-15 p, of four types: (1) fusoid-ventricose with flexuous walls and
obtuse apex (uncommon); (2) elliptic to elongate-elliptic, pedicellate (fairly
numerous); (3) ventricose with scarcely any neck and apex half as broad as
ventricose part (numerous), and (4) typically utriform, all with thin, smooth,
hyaline walls, cell content showing refractive granules in apex of some. Cheilocystidia variable in shape like the pleurocystidia and in addition some of them
clavate, hyaline in KOH.
Gill trama of moderately inflated interwoven hyphae with (in central strand)
yellow-brown smooth walls in KOH. Subhymenium cellular but cells not greatly
inflated. Pileus cuticle of clavate and vesiculose cells in a layer 2-3 deep, the
walls smooth, thin and hyaline or nearly so. Hyphae of subcuticular region clay
color to more rusty in KOH but walls smooth or nearly so. Clamps present.
Type locality. South Fork Boulder Creek, Owyhee County, Idaho.
Habit and habitat. Cespitose on soil under fir.
Distribution. Known only from the type locality.