The North American species of Psathyrella.

1972]

PSATHYRELLA

173

129. Psathyrella microcystis A. H. Smith, sp. nov.
Pileus 2-4 cm latus, demum late conicus, subspadiceus, ad marginem appendiculatus; lamellae pallidae demum purpureo-brunneae, confertae, secedentes
latae; stipes 5-10 cm longus, 2.5-5 cm crassus; pleurocystidia 32-48x7-11 /l,
subcylindrica vel anguste inflata, subacuta; fibulae adsunt. Typus. Smith 52744
(MICH); legit prope Trout Lake, Ophir, Colorado.
Illust. P1. 54, fig. a.
Pileus 2-4 cm broad, obtusely conic, expanding to broadly conic, "buckthorn
brown" (rich honey brown) moist, hygrophanous, fading to pale ochraceous buff
(pallid buff); margin at first appendiculate from remains of the veil. Context
thin, not markedly fragile, odor and taste not distinctive.
Lamellae tilleul buff (pallid) becoming purplish brown at maturity, close,
ascending-adnate, seceding, moderately broad.
Stipe 5-10 cm long, 2.5-5 mm thick at apex, often crooked, white, with a thin
coating of fibrils from the partial veil, pruinose above the veil line.
Spores 8-10x4-5 u, smooth, apical pore distinct, shape in face view elliptic
to ovate, in profile subelliptic to obscurely inequilateral, color in KOH dull cocoabrown slowly becoming somewhat chocolate-color, in Melzer's reddish tawny,
wall about 0.2-0.3, thick.
Basidia 18-22x8-9 /u, 4-spored, clavate, hyaline in KOH. Pleurocystidia
scattered, 32-48x7-11 ju, subcylindric with flexuous neck and subacute apex,
varying to narrowly ventricose, wall smooth, thin and hyaline. Cheilocystidia
28-37x9-15,/, vesiculose-pedicellate to fusoid-ventricose, apex in latter case
obtuse, wall smooth and hyaline, content not distinctive in either KOH or
Melzer's. Caulocystidia versiform: (1) clavate and 50-90 x 18-28 /, thin-walled,
smooth and hyaline, (2) cystidioid and 28-42 x 7-12 j, more contorted than the
pleurocystidia, (3) pedicellate-vesiculose and up to 25 u wide.
Pileus cuticle of vesiculose cells 2-3 deep and with hyaline, smooth, thin walls,
subcutis of hyaline to yellowish-hyaline hyphae in KOH, walls smooth. Clamp
connections present. No distinctive reaction of any tissue in Melzer's.
Type locality. Trout Lake, San Juan Mountains, Colorado.
Habit and habitat. Scattered to cespitose on duff of conifer needles and aspen
leaves mixed, August.
Distribution. Known only from the type locality.
Observations. The very narrow pleurocystidia with flexuous necks, the
medium-sized spores, the gigantic clavate caulocystidia, the submembranous veil,
white stipe and cespitose habit are distinctive.
Material examined. Colorado: Smith 51779, 52744 (Type).
130. Psathyrella crassulistipes A. H. Smith, sp. nov.
Pileus 1-2 cm latus, late convexus, demum subplanus, squamuloso-floccosus,
glabrescens, badius vel cinnamomeo-brunneus, ad marginem denticulato-appendiculatus; lamellae confertae, latae, brunneolae, demum fumoso-fulvae; stipes
2-4 cm longus, 2-5 mm crassus, cavus, pallidus, sparse fibrillosus; sporae 7-9
(-10) x4.5-5(-6) f/; pleurocystidia 32-44(-67) x9-14 [; fusoide ventricosa;
fibulae adsunt. Typus. Smith 53710 (MICH); legit prope Priest Lake, Idaho.
Illust. P1. 44; fig. b.
Pileus 1-2 cm broad, broadly convex with the margin curved in slightly,
expanding to nearly plane or the disc slightly depressed, surface at first covered