The North American species of Psathyrella.

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MEMOIRS OF THE NEW YORK BOTANICAL GARDEN

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chocolate-gray cast of old age develops. Context fragile, thin, dark brown fading
to cinnamon-buff or more cinnamon, odor and taste none.
Lamellae broad, horizontal, subdistant, broadly adnate, cinnamon-buff becoming deep chocolate-color (almost black), edges whitish.
Stipe 10-15 mm long, about 1 mm thick, equal, hollow, pale tan when young,
becoming whitish above, with scattered fibrils from the thin veil.
Spores 9-11 (-12.5) x 5-6.5 u, smooth, apical pore present but apex not
truncate, shape in face view ovate to (rarely) elliptic, in profile somewhat
inequilateral to obscurely so or (rarely) obscurely bean-shaped, color in KOH
dark cocoa-color when first revived in KOH, slowly becoming dark chocolatecolor, in Melzer's tawny (not with a strong red component showing), wall about
0.6 A thick.
Basidia 4-spored, 19-23 x9-10 pt, short-clavate, hyaline in KOH. Pleurocystidia 28-37x (9-)10-15,/, broadly fusoid-ventricose with a short usually
narrow neck and obtuse to subacute apex, smooth, hyaline in KOH, rarely with
a mucilaginous coating dried down on some part of the surface, content not distinctive. Cheilocystidia 22-37 x 10-18 t, ventricose-mucronate, clavate, or vesiculose, thin-walled, abundant, wall at base yellowish in KOH on some. Caulocystidia
not studied.
Gill trama with an obscure cinnamon tinge when first revived in KOH but this
soon fading. Pileus trama rusty yellowish in water mounts of fresh material,
pigment incrusted on the hyphae, cinnamon-brown as revived in KOH or in the
region of the subcutis darker russet. Cuticle of pileus an irregular palisade of
clavate pedicellate cells, these with rusty yellow bases in mounts in water when
fresh, and nearly russet revived in KOH, remainder of wall yellowish in KOH.
Clamp connections present. No distinctive reactions noted on any tissue in
Melzer's.
Type locality. Van Trump Park, elev. 6,000 ft., Mt. Rainier, Washington.
Habit and habitat. Gregarious among lichens.
Distribution. Mt. Rainier National Park, Washington.
Observations. The basidiocarps have about the stature of those of Psilocybe
atrorufa. The heavy pigmentation of the subcuticular hyphae, the somewhat
inequilateral spores in profile view, the short but broad pleurocystidia and the
broad horizontal subdistant gills along with the stature distinguish it.
277. Psathyrella subsericea A. H. Smith, sp. nov.
Pileus 1-2 cm latus, convexus, pallidus, sericeus non-hygrophanus; lamellae
latae, confertae griseae vel fusco-griseae; stipes 2-4 cm longus, 2-4 mm crassus,
albidus, nitens, sursum pruinosus, deorsum glaber; sporae 9-12 x 4.5-6.5 /; pleurocystidia 30-52 9-14 J, subfusoidea vel fusoide ventricosa, interdum flexuosa,
acuta vel obtusa; fibulae adsunt. Typus. Hesler 15919 (MICH); legit Knoxville,
Tennessee.
Pileus 1-2 cm broad, convex, dry, pallid, disc tinged tawny, not hygrophanous,
appearing glabrous but silky under a lens, not atomate, margin striate. Context
thin, fragile, odor and taste mild.
Lamellae rounded-adnate, broad, ventricose, close, "light mouse gray" to
"mouse gray," edges fimbriate.
Stipe 2-4 cm long, 2-4 mm thick, white and shining, apex pruinose, elsewhere
glabrous, hollow, dry, tapering downward or equal.
Spores 9-12 x 4.5-6.5 A, smooth, apical pore distinct and apex often distinctly