The North American species of Psathyrella.

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MEMOIRS OF THE NEW YORK BOTANICAL GARDEN

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near cinnamon-brown, hygrophanous, fading to pallid, rugulose at times. Context
very thin and fragile, odor none, taste not recorded.
Lamellae close, broad, adnate, blackish at maturity.
Stipe 2-3 cm long, about 2.5 mm thick, equal, fragile, pallid, fibrillose from
remains of the veil, glabrescent.
Spores 13-15(-18) x 6.5-8 A, smooth, apex truncate from a broad apical pore,
shape in face view ovate, in profile somewhat inequilateral, color in KOH bister
to mummy brown, slowly becoming dark chocolate-brown, in Melzer's dull reddish
tawny to bay-red, wall about 1 [ thick.
Basidia 2- and 4-spored, 20-34x10-13 A, hyaline or nearly so in KOH.
Pleurocystidia scattered, 46-62 x 9-15,/, fusoid-ventricose with tapered neck and
very acute apex, hyaline in KOH, smooth, thin-walled, cell content not distinctive
in KOH or Melzer's. Cheilocystidia abundant, similar to pleurocystidia or slightly
smaller, many smaller ellipsoid to clavate cells yellowish in KOH intermingled
with them. Caulocystidia similar to the pleurocystidia but more variable in size.
Gill trama dark cocoa-brown in KOH. Pileus trama dark cocoa-brown in
KOH, pigment thickenings in the wall near the septa numerous. Cuticle of pileus
a palisade of clavate to ellipsoid cells about 1 deep (or staggered somewhat), the
walls hyaline or ochraceous in KOH but near the base or in the pedicel pale rusty
brown. Clamp connections present. No distinctive reaction on any tissue in
Melzer's.
Type locality. Pole Mt. near Laramie, Wyoming.
Habit and habitat. Gregarious on campfire sites of recent (about a year old)
activity.
Distribution. Wyoming.
Observations. This species has the cystidial and tramal features of P. carbonicola but differs in having much larger spores.
Material examined. Wyoming: Smith 34553, 34609 (Type), 34612.
154. Psathyrella subrubella A. H. Smith, sp. nov.
Pileus 8-15 mm latus, conicus demum convexus, albo-fibrillosus, glabrescens,
fusco-brunneus dein avellaneus, tarde ad marginem incarnatus; lamellae latae,
confertae, adnatae, atro-brunneae; stipes 5-6 cm longus, 1-1.5 mm crassus, fragilis, pallidus demum griseus, fibrillosus, glabrescens; sporae (12-)13.5-17 (-20) x
6.5-8(-9) u; basidia tetraspora; pleurocystidia 30-44(-50) x9-14 [, fusoide
ventricosa, acuta; fibulae adsunt. Typus. Smith 22041 (MICH); legit prope
Douglas Lake, Michigan.
Illust. Text Fig. 347.
Pileus 8-15 mm broad, evenly and obtusely conic, becoming nearly convex,
surface at first covered by small patches of white fibrils from the remains of the
outer veil, moist and translucent striate, hygrophanous, chocolate-brown fading
to avellaneous but soon assuming a distinctly pinkish tint. Context membranous
and exceedingly fragile, pallid.
Lamellae broad, close, adnate, chocolate-brown to blackish, edges whitish.
Stipe 5-6 cm long, 1-1.5 mm thick, equal, very fragile, glabrous, whitish but
becoming dingy drab, yellowish tan when dry, soon glabrous, base white-strigose.
Spores (12-) 13.5-17 (-20) x 6.5-8 (-9) [, smooth, apical pore broad and causing
apex to appear truncated, shape in face view elliptic to narrowly ovate, in profile
suboval to obscurely inequilateral, at times the apical region extended into a short