The North American species of Psathyrella.

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MEMOIRS OF THE NEW YORK BOTANICAL GARDEN

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Basidia 4-spored, 22-26x9-12 p, clavate, hyaline in KOH. Pleurocystidia
abundant to scattered, (48-) 55-72x 8-12 (-14) u, when fresh often with a
mucilage-cap, typically fusoid-ventricose but the apex rounded and slightly wider
than the neck, hyaline, smooth, in KOH some with refractive particles in the
interior. Cheilocystidia shorter than the pleurocystidia but of the same type.
Caulocystidia versiform (Fig. 581).
Gill trama hyaline in water mounts of fresh material and only slightly brownish revived in KOH. Pileus trama sordid yellowish brown in KOH but fading on
standing; pileus cuticle of vesiculose cells 2-3 p thick and yellowish as revived in
KOH. Clamp connections present. No distinctive reactions observed on tissues
mounted in Melzer's.
Type locality. Cherryville, Oregon.
Habit and habitat. Gregarious on small branches of alder slash, October.
Distribution. Known only from the type locality.
Observations. The very broadly elliptic spores, the mucilaginous cap on many
cystidia in the fresh condition, the versiform caulocystidia, (many of which have
finger-like prolongations), and the discolorations over the lower part of the stipe
appear to be distinctive.
273. Psathyrella subpalustris A. H. Smith, sp. nov.
Pileus 8-15(-20) mm. latus, conicus, sparse griseo-fibrillosus, fusco-cinnamomeobrunneus; lamellae confertae, latae brunneolae demum griseo-brunneae;
stipes 3-6 cm longus, 1-2.5 mm crassus, pallidae demum brunneae; velum sparsum;
sporae 9-11 x 5-6(12-13 x 5-6) u; pleurocystidia 32-44 10-14 p, fusoideventricosa obtusa vel rotundata; fibulae adsunt. Typus. Smith 21412 (MICH);
legit prope Pinckney, Michigan.
Illust. Text Figs. 582-584.
Pileus 8-15(-20) mm broad, obtusely conic to convex, the margin slightly
incurved, expanding to broadly convex or nearly plane, surface at first covered
with a thin coating of grayish fibrils over marginal area, soon glabrescent, moist
and hygrophanous, "Mars brown" to "cinnamon-brown," hygrophanous and fading to near wood brown or avellaneous and closest to wood brown when dried,
margin faintly striatulate when moist. Context thin and fragile, odor none, taste
not distinctive.
Lamellae close, moderately broad, adnate but readily seceding, pallid brownish
young, becoming somewhat darker than "wood brown" at maturity (dark grayish
brown).
Stipe 3-6 cm long, 1-2.5 mm thick, hollow, very fragile, equal, pallid, becoming brownish in age, slightly fibrillose at least over lower part from the remains
of the veil, glabrescent.
Spores 9-11 x 5-6 p (a few 12-13 x 5-6 i), smooth, apex truncate from a wide
apical pore, shape in face view broadly elliptic to merely elliptic, in profile
elliptic to obscurely inequilateral, in KOH cocoa-color and remaining so for a
long time, finally clouded with chocolate-gray, in Melzer's clear tawny, wall about
1 p thick.
Basidia 4-spored 17-22 x 9-11 /, scarcely narrowed downward (6-8 U at base
in many). Pleurocystidia scattered, 32-44 x 10-14 u, fusoid-ventricose with obtuse
to rounded apex, wall hyaline, thin and smooth, content of cells in KOH or
Melzer's not distinctive. Cheilocystidia abundant, similar to the pleurocystidia
or saccate to clavate and 22-46x 10-16 u, the pedicel with slightly thickened