The North American species of Psathyrella.

1972]

PSATHYRELLA

327

very fragile, glabrous, hygrophanous, "Natal brown" (dark vinaceous-brown)
when moist, "vinaceous-fawn" (dingy pinkish) and atomate when faded, radially
wrinkled to subplicate. Context thin, dingy brownish, odor none.
Lamellae adnate with a decurrent tooth and line, ventricose and broad, subtriangular, subdistant, two tiers of lamellulae, "benzo brown" (purplish brown)
or when dried blackish brown, the edges "vinaceous-fawn" (pinkish).
Stipe 2-4 cm long, 1-1.5 mm thick, equal, hollow, fragile, dingy whitish fresh,
pale dull avellaneous when dried, easily splitting, glabrous except for the pruinose
apex.
Spores 12-14 (-17) x 7-8 /, smooth, apical pore present but apex not conspicuously truncate, shape in face view oblong to elliptic, in profile subelliptic to
obscurely inequilateral, date brown revived in KOH becoming dark date brown
to blackish, in Melzer's bay to bay-red, wall 1 u thick or slightly more.
Basidia 4-spored, 23-28x 10-15 A, clavate, hyaline in KOH. Pleurocystidia
scattered to rare, 36-63x 12-16 A, broadly ventricose above a narrow pedicel and
the apex acute to subacute, neck elongated and narrow and abruptly differentiated
from the ventricose part, hyaline smooth and thin-walled, cell content not distinctive in either KOH or Melzer's. Cheilocystidia abundant, of two types: fusoidventricose and hyaline or clavate and yellowish in KOH, the former 30-36x
9-12 p,, neck not much elongated, the latter clavate to ellipsoid and with very
slightly thickened walls. Caulocystidia very scattered, present as clavate end
cells much like some of the cheilocystidia.
Gill trama of enlarged cells more or less parallel and pale cocoa-color to
reddish brown in KOH. Pileus trama of floccose interwoven hyphae, pale cocoacolor to sordid tan or finally nearly hyaline (all in KOH), walls of hyphae
roughened. Cuticle of pileus of inflated cells with hyaline walls, some clavate or
pedicellate cells present but not numerous enough to form a palisade, the layer
irregularly 2 cells deep. Clamp connections present. No distinctive reactions
observed on any tissue as mounted in Melzer's.
Type locality. North Africa.
Habit and habitat. Scattered on soil in woods.
Distribution. Michigan, Tennessee.
Observations. Authentic material has not been examined hence the name is
used provisionally.
Material examined. Michigan: McCrea 507, 508, 529. Tennessee: Hesler
14213.
298. Psathyrella subdebilis A. H. Smith, sp. nov.
Pileus 1-4 cm latus, conicus vel campanulatus, glaber, pallide cinnamomeae;
lamellae pallidae demum fusco-brunneae, latae, confertae; stipes 4-11 cm longus,
2-3.5 mm crassus, pallideae, glaber; sporae 11-14 x 5.5-7 A; pleurocystidia lecythiformis vel fusoideo-ventricosa, 36-57x10-17 pA; fibulae adsunt. Typus. Smith
78344 (MICH); legit prope Adrian, Michigan.
Pileus 1-4 cm broad, obtusely conic becoming broadly conic to campanulate,
surface glabrous, moist and hygrophanous, when mature striate if moist, pale
cinnamon fading to pale pinkish buff, margin straight on button stages and naked.
Context concolorous with the surface when faded or moist, very fragile, taste mild,
odor fungoid, FeSO4-no reaction.
Lamellae pallid becoming brownish then avellaneous, finally pale to medium