The North American species of Psathyrella.

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MEMOIRS OF THE NEW YORK BOTANICAL GARDEN

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face view broadly elliptic to ovate, in profile obscurely inequilateral to subelliptic, color when first revived in KOH resembling that of a roasted coffee bean,
soon darkening to fuscous, in Melzer's dark tawny-red, wall about 0.4 K thick.
Basidia 4-spored, 16-20 x 10-13 a, subglobose-pedicellate, hyaline in KOH.
Brachybasidioles present. Pleurocystidia 40-70 x 10-18 /, fusoid-ventricose with
broadly rounded to obtuse apex, smooth, wall thin (in a few), in most the
wall 1-1.5 u thick in the neck and highly refractive, but thin again over the
apex, content of cell not distinctive. Cheilocystidia more or less similar to
pleurocystidia but walls typically thin to 0.6 / thick.
Gill trama regular, the hyphae with greatly inflated cells with hyaline
to dingy ochraceous walls. Pileus trama vinaceous-brown in KOH but soon
fading, having pigment thickenings near the cross walls. Cuticle of pileus a layer
of vesiculose cells 2-3 cells deep, their walls thin, smooth and hyaline to ochraceous. Clamp connections present.
Type locality. Papoose Creek, near Riggins, Idaho.
Habit and habitat. Under birch, gregarious.
Distribution. Known only from the type locality.
Observations. The thickened walls of the pleurocystidia as revived in KOH
distinguish this species readily from P. atrofolia. It illustrates again, how individual characters appear scattered through the genus. In this case we have
the correlation of brachybasidioles, pleurocystidia with thickened walls, and a
submembranous partial veil. In my estimation the species is not closely related
to those grouped around P. cystidiosa.
205. Psathyrella cloverae A. H. Smith, sp. nov.
Pileus 1.5-3 cm latus, demum convexus, copiose fibrillosus, glabrescens, sordide
cinnamomeus; lamellae angustae confertae, sordide brunneae; stipes 2-3 cm
longus, 2.5-3.5 mm crassus, glaber; sporae 8-9.5(-10.5) x 4-5(-5.5),/, in "KOH"
tarde fusco-brunneae; pleurocystidia 50-90x8-22 tu, crassotunicata (~+3 /).
Typus. Clover 1229 (MICH); legit prope Hildalgo County, Texas.
Illust. Text Figs. 477, 480.
Pileus 15-30 mm broad, obtusely conic to convex, surface tawny or darker
beneath a dense coating of delicate white fibrillose flecks representing the
remains of an outer veil, surface lubricous beneath the veil because of a slight
gelatinization of the cuticular cells, when dried near "Sayal brown" or with a
stronger cast of cinnamon. Context apparently rather firm and pliant (judged
by the way the tissue revived), odor and taste not recorded.
Lamellae narrow, crowded, narrowly adnate, dull brownish when dried.
Stipe short, 2-3 cm long, 2.5-3.5 mm thick, nearly equal above a narrow
marginate basal bulb (as seen on dried material), glabrous and pallid above,
brownish below (data taken from dried specimens).
Spores 8-9.5 (-10.5) x 4-5 (-5.5) /, smooth, apical pore present but not prominent and apex not distinctly truncate, shape in face view oblong to elliptic, in
profile obscurely inequilateral to bean-shaped, color in KOH cocoa-color slowly
darkening to chocolate-brown, in Melzer's tawny to reddish tan, wall about 0.3 IL
thick.
Basidia 26-30 x 7-9 t, narrowly clavate, 4-spored, hyaline in KOH. Pleurocystidia very abundant, 50-90 x 8-22 A, essentially fusoid but variable as to
shape, with walls up to 3, or more thick, apex incrusted or smooth, content
not distinctive in either Melzer's or KOH. Cheilocystidia present, of two types: