The North American species of Psathyrella.

1972]

PSATHYRELLA

293

distinct apical pore, shape in face view ovate to oblong, in profile obscurely
inequilateral to subelliptic, color in KOH dark mummy-brown (blackish), the
immature spores more ochraceous brown, Melzer's reaction not obtained, wall
about 1.2 gu thick.
Basidia 4-spored, hyaline in KOH. Pleurocystidia 40-56x 10-15 g, utriform
to fusoid-ventricose with rounded apex; wall thin, smooth and hyaline; content
not distinctive in KOH. Cheilocystidia similar to or shorter than the pleurocystidia and more of them fusoid-ventricose; wall thin, smooth and hyaline.
Caulocystidia not studied.
Gill trama not reviving. Pileus with a cuticle of vesiculose hyaline cells one
or possibly two cells deep, hyaline, thin-walled, smooth, content not distinctive
in KOH. Context not reviving well and apparently the hyphae not distinctive
in either KOH or in Melzer's, and lacking any distinctive type of organization.
Type locality. San Jose, California.
Habit and habitat. Cespitose in rich soil and grassy places under Sycamore.
Distribution. Known only from the type locality.
Observations. The gigantic spores, utriform or broadly rounded cystidia and
the stipe discoloring at the base along with the clustered habit are its claim to
distinction. Type studied.
259. Psathyrella rooseveltiana Murrill, Lloydia 5: 155. 1942.
Illust. Text Figs. 552, 553.
Pileus about 1 cm high and 1 cm broad, campanulate, umbonate, surface dry,
glabrous, radiate-sulcate, uniformly pale avellaneous tinged with old rose, (very
likely hygrophanous but faded when collected-A.H.S.), margin straight entire,
sulcate. Context very thin pallid, fragile.
Lamellae adnate, broad, distant, entire, with white edges.
Stipe 5-7 cm long, less than 1 mm thick, very slender, equal, smooth, glabrous,
pale reddish brown.
Spores 13-16(-18) x 7-9.5(-10) /, smooth, black in KOH, ovoid to ellipsoid,
not flattened, apical pore broad and distinct, apex truncate.
Basidia 18-23 x 10-14 g, 4-spored, broadly clavate, hyaline in KOH. Pleurocystidia scattered, 36-48 x 10-18 /, ventricose above a relatively long narrow
pedicel, neck very broad and apex broadly rounded, some elliptic-pedicellate,
thin-walled, hyaline in KOH, some with scattered highly refractive granules and
some with local lens-shaped wall thickenings. Cheilocystidia similar (or nearly
so) to the pleurocystidia, varying to ellipsoid, yellowish to hyaline in KOH (pigment in the wall). Caulocystidia not studied.
Gill trama of more or less interwoven hyphae. Pileus cuticle formed by
globose to clavate cells in a loose palisade, hyaline in KOH, cell content not
distinctive.
Type locality. Camp Roosevelt, Marion County, Florida.
Habit and habitat. In sandy soil on an exposed grassy road-shoulder.
Distribution. Known only from the type locality.
Observations. This species is distinguished by the rose tint of the faded
pileus, the broad distant lamellae, pale reddish brown stipe, large spores, very
broadly rounded pleurocystidia and the loose palisade forming the cuticle of the
pileus. The local wall thickenings in some cystidia are of a type observed in
various fleshy Basidiomycetes and Ascomycetes and are here not regarded as of
taxonomic significance. A closely related species is Drosophila calcarea Romag