The North American species of Psathyrella.

1972]

PSATHYRELLA

221

178. Psathyrella fulvobrunnea A. H. Smith, sp. nov.
Pileus 1-2.5 cm latus, conicus demum campanulatus vel convexus, sparse
fibrillosus, glabrescens, pallide fulvus, demum fusco-spadiceus; lamellae 2-4 mm
latae, confertae, demum subdistantes, brunneolae, demum fumoso-fulvae, stipes
3-4 cm longus, 2-3 mm crassus, fragilis, pallidus, fibrillosus demum glabrescens;
sporae 7-9 x 4-5 t; pleurocystidia 40-55 x 9-13 pt, anguste fusoideo-ventricosa;
fibulae adsunt. Typus. Smith 33-766 (MICH); legit prope Hulbert, Michigan.
Pileus 1-2.5 cm broad, obtusely conic, soon convex to campanulate or nearly
plane, surface at first with a thin coating of superficial fibrils which become
aggregated into scattered fascicles and eventually disappear, surface moist,
hygrophanous, striate to disc and tawny ("ochraceous-tawny") at first, gradually
becoming umber-brown ("mummy brown") but fading later to a pale buff ("warm
buff"), slightly rugose when faded. Context pallid, odor and taste not distinctive.
Lamellae broad (2-4 mm), bluntly adnate, close, becoming subdistant, pallid
brownish, finally dull rusty reddish brown or clouded with umber, edges even or
slightly fimbriate.
Stipe 3-4 cm long, 2-3 mm thick, fragile, equal, whitish, fibrous-striate or with
loose fibrils from the veil, pruinose above.
Spores 7-9 x4-5 /i, smooth, apical pore distinct and apex obscurely truncate
to rounded, shape in face view ovate to elliptic, in profile obscurely inequilateral
to somewhat bean-shaped, color in KOH cocoa-color slowly becoming clouded
gray (a medium chocolate-color), tawny to slightly redder in Melzer's, wall about
0.3 pt thick.
Basidia 18-22x8-10 A, 4-spored, hyaline in KOH, clavate. Pleurocystidia
40-55 x 9-13 A, narrowly fusoid-ventricose, apex subacute to obtuse, wall smooth,
thin and hyaline, cell content not distinctive in Melzer's or KOH. Cheilocystidia
similar to pleurocystidia or shorter. Caulocystidia mostly clavate hyphal ends but
a few resembling the pleurocystidia.
Gill trama regular, the cells inflated and somewhat irregularly arranged,
hyaline to pale tawny in KOH. Pileus trama pale tawny in KOH, the pigment in
the wall but walls smooth for the most part (a few pigment deposits near the
septa). Cuticle of pileus of inflated cells 1-2 deep, the walls thin and smooth,
hyaline to weakly yellowish (in KOH), cell content not distinctive. Clamps
present.
Type locality. Hulbert, Michigan.,
Habit and habitat. Solitary on small sticks of hardwoods.
Distribution. Known only from type locality.
Observations. The medium-sized spores, the thin pallid veil, ochraceous-tawny
color at first and subacute pleurocystidia are the important features.
179. Psathyrella similissima A. H. Smith, sp. nov.
Pileus 1-2.5 cm latus, conicus, demum campanulatus, sparse fibrillosus, glabrescens, cinnamomeo-fulvus; lamellae pallidae, demum cinnamomeo-fulvae, confertae; stipes 3-5 cm longus, 1.5-2.5 mm crassus, melleicolor, sparse fibrillosus,
glabrescens; sporae 7-8.5x4-4.5(-5) /; pleurocystidia 40-60x 10-16 L, fusoide
ventricosa; fibulae adsunt. Typus. Smith 71809 (MICH); legit prope Hulbert,
Michigan.
Illust. P1. 89, fig. b; Text Figs. 400-403.
Pileus 1-2.5 cm broad, obtusely conic with a straight margin, expanding to
campanulate or rarely convex at first, covered with a thin but very distinct outer