The North American species of Psathyrella.

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MEMOIRS OF THE NEW YORK BOTANICAL GARDEN

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Basidia 4-spored, 17-22(-36) x 8-9 /u, clavate. Pleurocystidia abundant, 46 -70(-80) x (8-)10-18 I, fusoid to fusoid-ventricose, apex acute to obtuse, wall
smooth and up to 0.6 /u thick, dingy brownish to vinaceous to hyaline in KOH.
Cheilocystidia clavate, 12-20 x 6-14 IL, hyaline to ochraceous in KOH, the color in
the wall; also cells somewhat like the pleurocystidia present but many merely
fusoid-ventricose with thin walls.
Pileus cuticle a layer of hyaline to yellowish inflated cells, 2-3 deep and with
thin, smooth walls, content not distinctive. Hyphae of subcuticular region merely
ochraceous to brownish in KOH and having smooth walls. Clamps present.
Type locality. Aylesford Lake, King County, Nova Scotia, Canada.
Habit and habitat. Scattered on soil at edge of a bog, July.
Distribution. Known only from type locality.
Observations. This species appears to be close to P. squamosa but features
cystidia coloring vinaceous-brown to some extent when revived in KOH, in their
having thinner walls, and in the spores being more elongate.
194. Psathyrella undulatipes A.H. Smith, sp. nov.
Pileus 2-4.5 cm latus, conicus vel late conicus, floccoso-squamulosus, glabrescens, spadiceus; lamellae confertae, latae, brunneolae demum fusco-brunnae;
stipes 8-11 cm longus, fragilissimus undulatus, fibrillosus, glabrescens; sporae
8-11 X 4-4.5 (-5) tt; pleurocystidia 38-64 (-76) x 10-17, fusoide ventricosa, obtusa vel subacuta; fibulae adsunt. Typus. Smith 20084 (MICH); legit prope
Rhododendron, Oregon.
Pileus 2-4.5 cm broad, obtusely conic, remaining so or expanding to broadly
conic, surface at first dotted with fine fibrillose squamules from the remains of
a white outer veil, soon glabrous over all including the margin, color "Prout's
brown" becoming dingy wood brown (medium date brown becoming grayer in
maturing), striatulate on margin when moist, hygrophanous and fading to dingy
tan, fading first on the margin. Context exceedingly thin and fragile but rigid,
concolorous with surface, odor and taste not distinctive.
Lamellae moderately close, 2 tiers of lamellulae present, broadest at stipe
and tapered to the pileus margin, adnate, not readily seceding (breaking near
the stipe before separating from it), color dingy pale brownish becoming chocolate-brown to a more violaceous-brown, dark vinaceous-brown as dried, edges
even.
Stipe 8-11 cm long, 2.5-3.5 mm thick above, equal or slightly enlarged downward, hollow, exceedingly fragile, hollow, white, most of them conspicuously
undulating, at first with scattered white fibrils from the veil over the lower portion and with an evanescent fibrillose zone where the veil breaks.
Spores 8-11 x4-4.5(-5),/, smooth, apical pore present but small and inconspicuous, spore apex not truncate, shape in face view oblong to narrowly elliptic,
in profile obscurely bean-shaped to narrowly elliptic, color in KOH cocoa-color
darkening to chocolate-brown and finally pale chocolate-gray, in Melzer's tawny
to reddish tawny, wall about 0.3 KL thick.
Basidia 4-spored, short-clavate, 16-20x 8-9 IL, hyaline. Pleurocystidia abundant, 38-64 (-76) x 10-17 lA, fusoid-ventricose with apex obtuse to subacute, surface
often with scattered adhering granules or coagulated droplets, hyaline, thinwalled, content of cell not distinctive. Cheilocystidia similar to pleurocystidia
but smaller, often with adhering granules or droplets.
Pileus cuticle a layer of inflated cells 2-3 deep, their walls thin, smooth,
hyaline and slightly refractive in KOH, the cell content not distinctive ("empty").