The North American species of Psathyrella.

1972]

PSATHYRELLA

377

hyaline, cell content not distinctive. Cheilocystidia narrowly fusoid to subfusoid,
32-46 x 7-11 t, hyaline, thin-walled.
Gill trama of greatly inflated hyphal cells with walls dingy vinaceouscinnamon and smooth; subhymenium of narrow compactly interwoven hyphae
in a narrow zone. Pileus cuticle a layer of vesiculose cells 2-5 deep, the walls thin,
smooth and hyaline to weakly ochraceous (in KOH). Hyphae of trama vinaceouscinnamon in KOH with some incrustations on the walls, the color dark near the
subhymenium and paler near the cuticle (the reverse is normally true). Clamps
present.
Type locality. Indian Gap, Great Smoky Mountains National Park, Tennessee.
Habit and habitat. Gregarious on a fallen beech branch, September.
Distribution. Known only from the type locality.
Observations. This is a distinctive species because of the reverse color pattern
of the pilear trama in KOH, and the greatly inflated cells of the lamellar trama
(central portion) in contrast to the narrow interwoven hyphae of the subhymenium.
351. Psathyrella baragensis A. H. Smith, sp. nov.
Pileus 1-3.5 (-4) cm latus, convexus vel conicus, ad marginem albo-fibrillosus,
glabrescens, spadiceus vel cinnamomeo-brunneus; lamellae pallidae demum atrobrunneae; confertae vel subdistantes, latae, demum ventricosae; stipes 2-4.5 cm
longus, caespitosus vel gregarius, 1.5-5 mm crassus, deorsum dilute brunneus,
fibrillosus, glabrescens; sporae 8-11 x 4-5 t; pleurocystidia 48-62 x 9-16 pt, fusoide
ventricosa vel subutriformia, obtusa vel subcapitata; fibulae adsunt. Typus.
Ammirati 2784 (MICH); legit prope Herman-Silver River, Baraga County,
Michigan.
Pileus 1-3.5(-4) cm broad, conic to obtusely conic, becoming expanded to
convex or nearly so, umbo if present typically rounded, margin at first appressed
against the stipe in buttons, spreading at times and splitting in age, fragile, moist,
hygrophanous, smooth, striate on the margin, opaque, when young whitish fibrillose on the margin from the veil at first, color "warm sepia" to "bister" becoming
"cinnamon-brown" to "ochraceous-tawny," paler tan when faded, finally dull
brown from the spores, dingy brown as dried. Context thin, watery under the
cuticle, brownish in the disc, odor and taste not distinctive.
Lamellae pallid to very pale cinnamon-buff, then grayer, finally dark gray
to black and drying blackish, close to subdistant, ascending adnate to adnexed,
broad at maturity and ventricose finally, no pink tints noted.
Stipe 2-4.5 cm long, apex 1.5-5 mm thick, irregular to curved, equal or slightly
enlarged downward, ground color watery brownish in age, brittle, hollow, context
brownish, fibrillose from the whitish remains of the veil, glabrescent.
Spores 8-11 x 4-5 u, smooth, apical pore distinct and apex more or less
truncate, shape in face view elliptic to ovate, in profile obscurely inequilateral,
color in KOH cocoa-brown becoming dark chocolate-color, in Melzer's dark bay.
Basidia 4-spored, 18-26 x 9-11 f, hyaline in KOH. Pleurocystidia scattered,
48-62 x 9-16,j, fusoid ventricose to subutriform, apex typically obtuse varying to
subcapitate (but under 6 t broad), less frequently subacute, smooth, wall thin
to slightly thickened (in KOH) and yellowish, cheilocystidia similar to pleurocystidia (some with thickened yellowish walls).
Gill trama in subhymenial area brownish (as in Lacrymaria), central strand
of inflated hyphal cells with smooth walls very weakly brownish in KOH on