The North American species of Psathyrella.

364

MEMOIRS OF THE NEW YORK BOTANICAL GARDEN

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brownish over lower area and when dried near "Sayal brown" over all, glabrous
or nearly so.
Spores 6-7 x 3-3.5 f, smooth, apical pore not evident, apex rounded; shape in
face view oblong to elliptic or a few subangular, in profile somewhat bean-shaped;
color in KOH cocoa-brown to chocolate-brown to fuscous, pale tan in Melzer's,
wall about 0.2,u thick.
Basidia 4-spored, clavate, 17-24 x 6-8 t, hyaline in KOH. Pleurocystidia
scattered, 36-48(-54) x 9-16 /, utriform to nine-pin-shaped and then the apex
5-9 tt broad, hyaline to yellowish in KOH but smooth and thin-walled. Cheilocystidia similar to pleurocystidia varying to clavate, ochraceous (often) in KOH.
Pileus cuticle a layer of inflated cells 2-4 deep, the walls brownish ochraceous
in KOH, thin, nearly smooth. Hyphae of subcuticular zone coarsely incrusted
with ochraceous-fulvous material and the septa heavily pigmented. Clamps
present.
Type locality. Skanee Road, East Branch of Huron River, Baraga County,
Michigan.
Habit and habitat. Clustered on rotten conifer logs, June.
Distribution. Known only from the type locality.
Observations. The habitat on conifer wood, the ochraceous cuticular cells as
revived in KOH, the predominantly dumbbell-shaped pleurocystidia and brown
stipe as dried are distinctive along (apparently) with the lack of a veil. It is
closest to P. fuscofolia.
337. Psathyrella acadiensis A. H. Smith, sp. nov.
Pileus 2.5-6 cm latus, subplanus, glaber, rugoso-reticulatus, rufo-fulvus, dein
pallide brunneus; lamellae angustae, confertae, fulvae, demum vinaceo-brunneae;
stipes 4-8 cm longus, 3-6 mm crassus, pallidus, deorsum demum brunneus; velum
sparsum; sporae 5-6 x 3 I,; pleurocystidia 32-48x 8-12 I, utriformia vel fusoide
ventricosa, obtusata; fibulae adsunt. Typus. Harrison 8120 (MICH); legit prope
Kentville, Nova Scotia, Canada.
Pileus 2.5-6 cm broad, obtusely conic expanding to nearly plane or with a low
broad umbo, surface glabrous, moist, hygrophanous, rugose-reticulate, russet to
cinnamon-brown fading to pale tan, with a thin fibrillose fringe of veil remnants
along the margin at first. Context pale tan when faded, darker when moist, odor
distinctly musty.
Lamellae narrow, crowded, adnate, soon rusty brown and drying vinaceousbrown to cocoa-brown, edges whitish.
Stipe 4-8 cm long, 3-6 mm thick, equal or enlarged downward, flexuous, hollow,
fragile, white-mycelioid around the basal area, surface ridged and roughened,
whitish becoming brownish.
Spores 5-6x3 /, smooth, truncate from an apical pore, shape in face view
oblong to narrowly elliptic, in profile suboblong to bean-shaped, color in KOH
pale chocolate-brown becoming pale chocolate-gray; pale tawny in Melzer's, wall
about 0.2 / thick.
Basidia 4-spored, 15-18 x5-6 /, narrowly clavate. Pleurocystidia 32-48 x
8-12 A, utriform to fusoid-ventricose with very obtuse apex, smooth, thin-walled,
hyaline, often pale cinnamon when first revived, content not distinctive. Cheilocystidia similar to pleurocystidia or varying to clavate, hyaline.
Pileus cuticle a compacted trichodermium with elements 1-3 cells long and
having inflated cells or clavate-pedicellate cells some up to 80 u long, walls hyaline