The North American species of Psathyrella.

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MEMOIRS OF THE NEW YORK BOTANICAL GARDEN

[VOL. 24

Illust. Text Figs. 86-88.
Pileus 3-5 cm broad, obtuse when young, expanding to nearly plane or
retaining a low umbo, surface moist and hygrophanous, at first covered by
minute white squamules from an outer veil, glabrescent, color when moist a
dark honey brown, fading to pallid but when dried dull tawny-brown. Context
thin, fragile, concolorous with surface, odor and taste not distinctive.
Lamellae close, moderately broad, adnate but soon seceding, pale dingy cinnamon (in youngest) becoming dark dingy cinnamon ("Verona brown") and
when dried dark cocoa-color, edges pallid and even.
Stipe 9-13 cm long, 5-9 mm thick, equal, hollow, fragile, whitish over all
and unchanging, silky below the superior membranous annulus, striate-pruinose
over apical region; annulus thin and membranous, striate above, squamulose
on the under side, darkening to avellaneous-brown in drying.
Spores 11-14(-15) X6-7.5 A, smooth, apical pore not evident and apex not
truncate, shape in face view broadly fusiform to ovate-fusiform, pointed at the
apiculate end, apex less so but not rounded, in profile inequilateral to somewhat
inequilateral (or the ventral line almost straight if plage area is very broad
and merely flattened), color in KOH cocoa-brown becoming very dark cocoabrown, in Melzer's rich tawny, wall about 0.3, thick.
Basidia 24-30 9-12 ~, 4-spored, clavate, hyaline in KOH. Pleurocystidia
scattered, 46-77 x 13-20, broadly fusoid-ventricose with a wide (10-12 p)
neck and broadly rounded apex, in some broadly fusoid and more abruptly tapered
to a subacute apex, thin-walled, smooth, hyaline, content not distinctive. Cheilocystidia similar to pleurocystidia but neck narrower and often greatly elongated
and with the apex merely obtuse, the basal ventricose part 10-14 t wide.
Gill trama regular, the hyphae with greatly elongated and inflated cells with
thin, smooth, hyaline walls. Pileus trama hyaline in KOH or at first (in young
pilei) brown in the subcuticular region but fading, walls smooth and hyaline at
maturity. Cuticle of pileus a layer 3-5 cells deep, of vesiculose elements with
pale dingy ochraceous walls in KOH which are thin and smooth. Clamp connections present but rare in material examined to date. Veil hyphae with one type
having cinnamon colored walls in KOH which are thin and smooth.
Type locality. Tule Bay, Priest Lake, Idaho.
Habit and habitat. Gregarious on conifer duff under old-growth hemlocks.
Distribution. Known only from the type locality (Smith 76887).
Observations. This species is close to P. caputmedusae but lacks the odor
and heavy soft veil remnants of the latter below the annulus and has distinctly
larger spores. Both have the tendency of the necks of the cheilocystidia to
elongate.
30. Psathyrella sphagnicola (Maire) Favre, Bull. Soc. Mycol. Fr. 53: 282. 1937.
Stropharia sphagnicola Maire, Bull. Soc. Mycol. Fr. 26: 192. 1910.
Stropharia psathyroides Lange, Dansk. Bot. Arkiv. 4: 36. 1923.
Illust. Maire, op. cit. pl. 6, figs. 10-12; Favre; op. cit. fig. 5; Lange, op. cit. pl. 1,
fig. f. Text Figs. 89-92.
Pileus 1-2 (-3) cm broad, obtusely conic, becoming campanulate or expandedumbonate, surface at first with delicate fibrillose scales toward the margin, soon
glabrescent, when moist pale to dark chocolate-brown, margin striatulate, hygrophanous and fading to pale alutaceous or pale livid buff ("cinnamon-buff") or