The North American species of Psathyrella.

294

MEMOIRS OF THE NEW YORK BOTANICAL GARDEN

[VOL. 24

nesi (1966) which is vernal, grows in calcareous situations, and lacks rose tints
in age.
260. Psathyrella orizabensis (Murrill) A. H. Smith, comb. nov.
Psilocybe orizabensis Murrill, Mycologia 10: 29. 1918.
Illust. Text Figs. 554, 556.
Pileus 1.5 cm broad and high, conic, not expanding, not umbonate, surface
smooth, glabrous not striate, uniformly rosy isabelline, margin entire, concolorous. Context thin and fragile.
Lamellae adnate, crowded, broad, whitish at first, becoming dark isabelline,
with a rosy tint in addition.
Stipe 5 cm long, 1.5-2 mm thick, slightly larger below, glabrous, paler than
the pileus, rather brittle.
Spores 12-15 x 6-8 L, smooth with an oblique distinct apical pore causing
the apex to be somewhat truncated, shape in face view elliptic to slightly ovate,
in profile obscurely inequilateral to subelliptic, color in KOH fuscous becoming
dark chocolate-color, in Melzer's reddish tawny, wall about 1.0 u thick.
Basidia 4-spored, 20-28 x 10-15 /, clavate, hyaline in KOH. Brachybasidioles
apparently differentiated in old caps. Pleurocystidia abundant, 42-64 x 10-18 j,
ventricose above a narrow pedicel, tapered to an obtuse to broadly rounded
apex, the apical region of the cell filled with highly refractive granules as revived
in KOH (the granules yellowish in Melzer's), wall thin and colorless. Cheilocystidia similar to pleurocystidia varying to saccate but with apical region
containing granular material.
Gill trama regular, sordid yellowish brown in KOH. Pileus trama sordid
yellowish brown in KOH, no obvious pigment incrustations seen (on mounts
of the type). Pileus cuticle of hyaline vesiculose cells 1-2 cells deep; the walls
thin, smooth and hyaline; cell content not distinctive. Clamp connections present.
Type locality. Orizaba, Mexico.
Habit and habitat. Solitary to scattered on the soil.
Distribution. Mexico. United States: Kansas, Michigan.
Observations. Among the large spored species the granular content of the
apical region in the cystidium is the key character.
Material examined. MEXICO. Orizaba: Murrill (the type). UNITED
STATES. Kansas: Brooks 1598, 1602, 1603. Michigan: Smith 21432.
261. Psathyrella pseudofrustulenta A. H. Smith, sp. nov.
Pileus 10-15 mm latus, convexus demum planus, sparse fibrillosus, glabrescens,
fulvus; lamellae latae, subdistantes, fulvae; stipes 1-2 cm longus, 1 mm crassus,
sparse fibrillosus; pallidus; sporae 11-14(-15) x5.5-7 /; pleurocystidia 37 -48 (-56) x 10-16,u, fusoide ventricosa, obtusa vel rotundata; fibulae adsunt.
Typus. Smith 39894 (MICH); legit Mt. Rainier National Park, Washington.
Illust. Text Figs. 555, 557, 558.
Pileus 10-15 mm broad, convex expanding to plane, the margin straight or
bent in slightly at first, the surface at first with a thin coating of pallid to
grayish fibrils, soon glabrescent, color "russet" (dark rusty brown), hygrophanous
and fading to cinnamon-tan. Context very thin and fragile, lacking a distinctive
odor or taste.