The North American species of Psathyrella.

1972]

PSATHYRELLA

285

Spores 5.5-6.5 (-7) x 3.2-3.8 I, smooth, apical pore present but small and apex
not truncate, shape in face view oblong to elliptic, in profile subelliptic or
obscurely inequilateral, color in KOH pale avellaneous with a suggestion of
an ochraceous overtone, darkening to pale chocolate-color, in Melzer's tawny
to more reddish-cinnamon, wall about 0.2 f/ thick or less.
Basidia 14-16x 6-7,, 4-spored, hyaline in KOH. Brachybasidioles possibly
present at maturity. Pleurocystidia not found (type revived poorly). Cheilocystidia abundant and very large, 32-44 x 10-20 /, ventricose with broadly
rounded apex varying to ellipsoid, hyaline, thin-walled and readily collapsing.
Gill trama more or less parallel in hyphal arrangement, hyaline in KOH.
Pileus trama of interwoven hyaline (in KOH) hyphae; the cuticle of vesiculose
hyaline cells in a layer one-cell thick.
Type locality. Cinchona, Jamaica.
Habit and habitat. Solitary on decaying logs.
Distribution. Known only from the type locality.
Observations. The very small spores, lignicolous habitat, snow-white stipe,
lack of a veil and large cheilocystidia are distinctive. The species needs to be
restudied from fresh material. In mounts of the pileus tissue in Melzer's some
patches of dark violet (amyloid?) debris were found in some of the hyphae,
reminding one of the content of some cystidia in the bolete genus Tylopilus!
These, if characteristic, would form an additional important taxonomic character.
247. Psathyrella campestris (Earle) A. H. Smith, comb. nov.
Gymnochilus campestris Earle, Inf. An. Estac. Centr. Agron. Cuba 1: 238. 1906.
Hypholoma campestre (Earle) Morgan, Jour. Mycol. 14: 30. 1908.
Drosophila campestris (Earle) Murrill, Mycologia 10: 64. 1918.
Illust. Earle, 1. c. pl. 38. Text Figs 543, 544.
Pileus 2-5 cm broad, campanulate then expanded, glabrous, hygrophanous,
at first grayish brown, then argillaceous, darker in the center, becoming reticulate
and striatulate when dry. Context very thin, very fragile.
Lamellae narrow, close, adnexed, at first grayish brown, at length dark
brown.
Stipe 4-6 cm long, 2-4 mm thick, fistulose, fragile, white, glabrous except at
the summit where it is striate and floccose and pulverulent.
Spores 7-9 x 4.5-5.5 /, smooth, apical pore small and spore apex not truncate,
shape in face view elliptic to ovate, in profile elliptic to obscurely inequilateral,
color in KOH a dull cinnamon ("Sayal brown"), darkening slowly, in Melzer's
tawny to reddish tawny, wall about 0.2,u thick.
Basidia short and fat, 18-20x 10-12 [, 4-spored, hyaline in KOH. Pleurocystidia none. Cheilocystidia abundant, ventricose with broadly rounded apex to
subcylindric, hyaline in KOH, collapsing readily, 28-42 x 10-15 /. Caulocystidia
scattered over apical region, 28-65 x 8-20 u, clavate, fusoid-ventricose with
broadly rounded apex or subcylindric and 6-9 [ wide, some with localized
refractive thickenings on interior wall, some apparently filled with a mucilaginous substance.
Gill trama not reviving well, apparently merely brownish to hyaline in KOH.
Pileus trama colored like the gill trama and also reviving poorly. Cuticle of
pileus of vesiculose cells apparently about 1 cell deep. Clamp connections present
but difficult to demonstrate.
Type locality. Santiago de las Vegas, Cuba.