The North American species of Psathyrella.

1972]

PSATHYRELLA

439

fusoide ventricosa. Typus. Smith 80861 (MICH); legit prope Midland, Michigan,
ad terram arenosam.
Pileus 2.5-4 cm broad, broadly convex with an incurved margin, margin
delicately appendiculate but soon naked, expanding to nearly plane with a
decurved margin, soon glabrous over all including the edge, no appreciable
development of an outer veil, color bister fading (on margin first) to pinkish buff,
disc near cinnamon buff as dried. Context thin, pallid, fragile; odor none.
Lamellae close, narrow, bluntly adnate, pallid brownish becoming drab,
horizontal, edges even.
Stipe 2-3 cm long, 3-4 mm thick, equal to slightly enlarged downward, tubular, pallid within, not markedly fragile; surface whitish over all and not discoloring appreciably in drying, thinly silky to naked; veil remnants sparse and
inconspicuous.
Spores 8.5-11 x 3.5-4 (-4.5) tt, smooth, apical pore indistinct or in large spores
apex obscurely snout-like, shape in face view subovate to oblong varying to
obscurely angular in some and subfusoid in others, in profile suboblong to narrowly obscurely inequilateral to somewhat bean-shaped, color in KOH cocoabrown becoming darker in KOH.
Basidia 4-spored. Basidioles clavate. Pleurocystidia none or near edge and
then similar to cheilocystidia. Cheilocystidia abundant, 36-52 x 10-15 t, utriform
to fusoid-ventricose with rounded apex, some clavate, hyaline, thin-walled,
smooth.
Gill trama of inflated regularly arranged cells, hyaline to brownish in KOH;
subhymenium thin but cellular. Pileus cuticle a layer 2-3 cells deep of inflated
cells with hyaline to brownish walls in KOH. No distinctive pigment incrustations
noted anywhere. Clamps present.
Habit, habitat and distribution. Cespitose in small groups along the side of
a sand-road, City Park, Midland, Michigan, Oct. 13, 1971, Smith 80861.
Observations. Although described from a single collection, this species has
been recognized for years in the central part of the state, but never in good condition. It features unusually long spores with a snoutlike apex in some (more so
from some basidiocarps than others). In the type this feature is not pronounced
though still recognizable. It was spore variability in single basidiocarps that
caused me to be skeptical as to whether the odd assortment of mature basidiocarps
observed over the years actually represented a species.
411. Psathyrella subochracea A. H. Smith, sp. nov.
Pileus 1-2 cm latus, obtuse conicus, ad marginem appendiculatus et rimosus,
albosquamulosus, glabrescens, pallide ochraceus, demum olivaceo-brunneus,
deinde ochraceo-albidus; valde fragilis; lamellae albidae demum avellaneae,
confertae, adnatae, latae; stipes 1-2 cm longus, 1.5 mm crassus, fragilis, cavus,
sursum albidus, deorsum melleus, albo-floccosus, glabrescens; sporae 6-7.5 X
3.5-4.5 /,; pleurocystidia nulla. Cheilocystidia 38-56x10-15,u, fusoide ventricosa vel utriformia, intus ad apicerum cum granis hyalinibus. Typus. Smith 78378
(MICH); legit prope Ann Arbor, Washtenaw County, Michigan, 14 July, 1970.
Pileus 1-2 cm broad, obtusely conic becoming broadly conic, oldest ones split
on the margin, when young pale dingy ochraceous beneath white squamules of
outer veil material; margin appendiculate with pieces of partial veil, glabrescent
becoming olive-brownish to avellaneous, then fading to yellowish white and very