The North American species of Psathyrella.

1972]

PSATHYRELLA

387

Lamellae broad (5 mm or more), adnate, seceding, distant to subdistant,
brownish when young, "Verona brown" when mature, edges whitish.
Stipe 2.5-3 cm long, 1-1.5 mm thick, equal, very fragile, white over all and
thinly silky fibrillose to the pruinose apex, veil fibrillose and rudimentary.
Spores 8-11x4-5(-6) I,, smooth, apical pore distinct under low power oilimmersion but spore apex rounded, shape in face view elliptic to ovate, in profile
subelliptic to obscurely bean-shaped, color in KOH cocoa-brown, slowly darkening
(revived in KOH), in Melzer's tawny-red, wall about 0.5 t thick.
Basidia 4-spored, 8-9 pt broad, hyaline. Brachybasidioles present at maturity
8-12 KA wide. Pleurocystidia 52-68(-75) x10-16 ai, broadly fusoid to fusoidventricose, rarely bifurcated at the apex, smooth, thin-walled, hyaline, cell content not distinctive, apex obtuse to somewhat rounded. Cheilocystidia vesiculose
to clavate, with yellowish walls in KOH and these 0.3-0.5 pA thick as revived in
KOH, some fusoid but smaller than the pleurocystidia and hyaline. Caulocystidia
versiform, as chains of inflated cells, as clavate to ellipsoid-pedicellate cells or as
fusoid-ventricose cells, some clavate cells up to 70 x 25 I, walls thin, smooth and
hyaline.
Cuticle of pileus a layer of inflated cells 3-4 deep, their walls yellowish in
KOH, some cells clavate to cystidioid, vesiculose cells up to 50 IA wide also present,
cell content not distinctive, walls smooth. Hyphae of the subcuticular region dull
cinnamon in KOH but fading to ochraceous, walls smooth or nearly so. Clamps
present. No distinctive reactions present on material revived in Melzer's.
Type locality. Tahquamenon Falls State Park, Luce County, Michigan.
Habit and habitat. Scattered on rotten hardwoods-logs, stumps etc., June.
Distribution. Michigan, Washington.
Observations. The distinctive features of this species are the watery cinnamon
color of the fresh pileus, broad more or less distant gills, pallid stipe over all,
versiform caulocystidia and the large pleurocystidia.
Material examined. Michigan: Smith 66717 (Type). Washington: Smith
30389.
362. Psathyrella fulvescens (Romagnesi) Moser in Gams, Kleine Kryptogamenfl.
233. 1955.
Drosophila fulvescens Romagnesi, Bull. Mens. Soc. Linn. Lyon 21: 153. 1952.
Illust. P1. 72, fig. b; Text Figs. 813-816.
Pileus 15-25(-30) mm broad, obtusely conic to convex, becoming broadly
campanulate to broadly convex, surface moist and with scattered fibrils over the
marginal area or to the disc in buttons, soon glabrous except for a few fibrils along
the margin (veil almost rudimentary and pallid to pale buff in color when enough
is present to show the color), translucent-striate before fading, hygrophanous
"cinnamon-brown" to "tawny" or ochraceous-tawny to pale yellowish brown
("clay color") or pale tan, paler when faded (sometimes nearly pallid). Context
very thin, fragile, pallid, odor and taste not distinctive.
Lamellae broadly and bluntly adnate, close to nearly subdistant, 1-2 tiers of
lamellulae, narrow to moderately broad to (finally) broad, not seceding readily,
pallid brownish young, becoming dark cocoa-brown with a purplish tone in age,
edges even but often whitish.
Stipe 3-5 cm long, 1-2.5 (-3) mm thick, equal, tubular, very fragile, white or
whitish, base tinged honey-color at least in age, pruinose near the apex, at first