The North American species of Psathyrella.

1972]

PSATHYRELLA

289

Lamellae broad, adnate, pallid fuscous.
Stipe 10-20 mm long, white, changing to reddish, equal, slightly fistulose
(pileus and stipe tawny when dry).
Spores 7-8x 4-4.5 /, smooth, with an obscure apical pore hence apex not
truncate, shape in face view oblong to elliptic, in profile subelliptic to obscurely
bean-shaped, near "wood-brown" (gray-brown) in KOH.
Basidia 4-spored, 16-18x6-7 v, hyaline in KOH. Basidioles present rather
than brachybasidioles. Pleurocvstidia none. Cheilocystidia saccate, 22-28 X
9-12 a, hyaline, thin-walled, readily collapsing.
Gill trama not reliable because of being parasitized. Pileus having a cuticle
of vesiculose cells in a layer 1-2 cells deep. Hyphae of the subcuticular region
hyaline in KOH and with irregular refractive laticiferous elements present.
Clamps not demonstrated (but hyphae revived poorly).
Type locality. Cuba.
Habit and habitat. On logs.
Distribution. Known only from the type locality.
Observations. The white pileus, broad fuscous lamellae, white stipe changing
to reddish, and apparently the lack of brachybasidioles distinguish this species.
254. Psathyrella roystoniae (Earle) A. H. Smith, comb. nov.
Gymnochilus roystoniae Earle. Inf. An. Estac. Centr. Agron. Cuba 1: 239. 1906.
Hypholoma roystoniae (Earle) Morgan, Jour. Mycol. 14: 28. 1908.
Atylospora roystoniae (Earle) Murrill, Mycologia 10: 24. 1918.
Illlst. Earle, 1.. c..37, fig. 3. Text Fig. 548.
Pileus 1-3 cm broad, convex then expanded, obtuse, glabrous, somewhat
reticulate and striatulate, hygrophanous, pallid tinged with purple, becoming
whitish when dry (faded). Context thin and fragile.
Lamellae moderately broad, close, adnexed, at first pallid, at length purplebrown.
Stipe 2 cm long, 2 mm thick, short, fistulose, glabrous, white, with a mycelioid
base.
Spores 7-8 x4-4.5 /, smooth, apical pore distinct and apex truncate in most
but this obscure because the germ pore often bulges slightly in KOH (the outer
membrane becomes convex instead of remaining flat or concave), shape in face
view elliptic to obscurely ovate, in profile elliptic to obscurely inequilateral, color
in KOH pale dull cocoa-color becoming avellaneous and finally fading to nearly
hyaline, pale ochraceous-tawny in Melzer's, wall -0.2, thick.
Basidia 4-spored, hyaline in KOH, 7-8 u broad, clavate. Brachybasidioles
apparently present (reviving poorly). Pleurocystidia none. Cheilocystidia
scattered, saccate to ellipsoid, some broadly ventricose with obtuse apex, 22-28
x9-14 /, hyaline in KOH, thin-walled, readily collapsing. Gill trama not
reviving well but not distinctively colored. Pileus having a cuticle of vesiculose
hyaline cells about one cell deep. Hyphae of the subcuticular region merely
dingy ochraceous in KOH. Clamp connections present.
Type locality. Managua, Cuba.
Habit and habitat. Subcespitose on rotten trunks of Roystonia.
Distribution. Known only from the type locality.
Observations. The pallid pileus at first and the broad gills along with tne
habitat appear distinctive. Singer's (1951 p. 470) publication of the combination
P. roystoniae is not valid.