The North American species of Psathyrella.

1972] PSATHYRELLA 443
hymenium appearing cellular in sections but cells not much enlarged (5-10,
wide). Pileus cuticle a layer of vesiculose cells 2-3 deep, the walls hyaline to
dingy pale ochraceous (in KOH), cell content not distinctive. Subcutis pale
cocoa-color in KOH but fading, no appeciable hyphal incrustations noted. Clamp
connections present.
Habit, habitat and distribution. Densely gregarious on soil in the "parking"
strip possibly where a shade tree had been removed, Liberty St., Ann Arbor,
Michigan, Sept. 30,1971, Smith 80623.
Observations. The distinguishing features of this species are first its dingy
appearance, secondly the whitish rather densely floccose stipe (but lacking an
annular velar zone), the rare to scattered pleurocystidia and spores 5-6 e broad.
I have not encountered another species with a similarly ornamented stipe and so
little veil on the pileus in young specimens.