The North American species of Psathyrella.

1972]

PSATHYRELLA

79

39. Psathyrella membranacea A. H. Smith, nom. nov.
Stropharia tenuis Murrill, Mycologia 14: 137. 1922 (non Drosophila tenuis Murrill,
Mycologia 10: 65. 1918).
Illust. Text Figs. 112,113.
Pileus 2.5 cm broad, convex-subumbonate, surface hygrophanous, brown,
faintly striate, with delicate floccose patches from the remains of the veil. Context
very thin and fragile.
Lamellae adnexed, crowded, moderately broad, dark avellaneous.
Stipe 7 cm long, 2-3 mm thick, slender, fragile, tapering upward, enlarged at
the base, glabrous, silky, hollow, concolorous with pileus but slightly paler;
annulus about 2.5 cm from apex of stipe, white, ample, persistent.
Spores 7-8 x 4.5-5 I, smooth, with a small apical pore but apex not appearing
truncate, shape in face view elliptic to slightly ovate, in profile subelliptic to
obscurely inequilateral, pale chocolate gray as revived in KOH, wall about 0.2 /%
thick.
Basidia 4-spored, 18-20 x 9-11 a, clavate-capitate, hyaline in KOH. Brachybasidioles 10-16 x 9-14 /, hyaline and readily collapsing. Pleurocystidia not
found. Cheilocystidia abundant, saccate to clavate or broadly ventricose with a
slightly narrowed neck and very obtuse apex, thin-walled, hyaline, 25-38 x
10-18 pu.
Subhymenium cellular. Pileus with a cuticle of enlarged hyaline hyphal cells
20-40 x 15-30 A, the layer 1-2 cells deep, hyaline in KOH and thin-walled. Tramal
body brown in KOH and the hyphae with greatly inflated cells.
Type locality. Chalmitte, New Orleans, Louisiana.
Habit and habitat. Solitary on the ground in wet woods.
Distribution. Louisiana, Florida and British Honduras (type studied).
Observations. The scattered remains of an outer veil on the pileus, moderately
broad lamellae, brownish stipe, white ample annulus, spores pale chocolate-gray
in KOH, and lack of pleurocystidia all indicate clearly a relationship to the
annulate species of the subgenus Candolleana.
40. Psathyrella vanhermanii A. H. Smith, nom. nov.
Stropharia caespitosa Murrill, Mycologia 10: 71. 1918 (non Psathyrella caespitosa
Peck, 1907).
Illust. Text Fig. 114.
Pileus 3-5 cm broad, campanulate to convex, surface dry, pallid with brownish
shades, floccose-scaly, at length glabrous, rugose, margin thin, fluted, scarcely
striate. Context thin, very fragile, white, taste mild (pleasant).
Lamellae adnexed, crowded, rather narrow, white to pale purplish brown.
Stipe 7-10 cm long, 5-10 mm thick, subcylindric, tapering below, white, densely
floccose, hollow, veil white, thick, usually forming a more or less deciduous annulus
about 3 mm from the apex of the stipe.
Spores 6-7.5x3.5-4 (9-11x5) a, smooth, with a broad apical pore but not
appearing truncate unless the convex apical lens collapses, shape in face view
oblong to narrowly elliptic, in profile obscurely bean-shaped to subelliptic, color
as revived in KOH pale chocolate-gray, wall about 0.2 p thick.
Cheilocystidia 26-30 x 9-15 /, broadly and obtusely fusoid-ventricose, hyaline,
thin-walled and smooth as revived in KOH. Pileus with a cuticle of inflated
hyaline cells 10-20 u wide and hyaline in KOH.
The above description is drawn entirely from the type (Earle 204). The