The North American species of Psathyrella.

232 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN [VOL. 24
Illust. Text Figs. 430-434.
Pileus 1-2.5 cm broad, obtusely conic, expanding to convex or nearly so,
surface at first covered with a very thin coating of outer veil fibrils which soon
become arranged in scattered fascicles and disappear, margin fringed at first,
surface moist, hygrophanous, color "ochraceous-tawny" to cinnamon-brown
(about as in P. frustulenta), fading to pinkish buff or paler but some dingy tan
in age when faded. Context thin and fragile, watery brownish moist, odor and
taste not recorded.
Lamellae close, moderately broad, ascending adnate, pallid brownish becoming
"benzo brown" (violaceous-fuscous) to "hair brown" (dark brownish gray), and
when dried "chateura drab" (pale fuscous), not showing vinaceous-brown tones,
edges whitish.
Stipe 4-6 cm long, 1.5-3 mm thick, equal, fragile, whitish, base finally dingy
honey-brownish but not discoloring conspicuously, whitish when well dried,
fibrillose at first with fibrils from the veil but soon glabrescent.
Spores 9-10.5 x 5-6 a, smooth, pore apical and small (not affecting the contour
of the apex), shape in face view elliptic to slightly ovate, in profile subelliptic
to obscurely inequilateral, color in KOH dull cocoa-brown slowly becoming a
grayer chocolate-brown, reddish tawny in Melzer's, wall about 0.4. thick.
Basidia 18-20 x 8-9 p, 4-spored, hyaline in KOH, short-clavate. Pleurocystidia
scattered, fusoid-ventricose with elongated necks and obtuse to subacute apex,
42-65 x 9-13 /, wall thin, hyaline and smooth, cell content not distinctive. Cheilocystidia of two types: the first like the pleurocystidia but the neck not as long,
the second clavate to vesiculose and 10-20 x 6-12 pl, having the cell walls slightly
thickened in the lower part or over all and when revived in KOH the color pale
bister, the supporting hyphae often similarly colored. Caulocystidia scattered in
small groups, clavate to subcylindric or fusoid-ventricose, rarely with refractive
material adhering to inner surface of wall at or near the apex, extremely variable
in size from 70 x 20 [u for large fusoid-ventricose cells down to 15 x 10 ju for small
subglobose cells, all hyaline in KOH.
Gill trama cocoa-color in KOH at first but fading, pigment in the smooth wall.
Pileus trama vinaceous-brown fading to cocoa-brown, color rather persistent in
young pilei (located in the wall). Cuticle of pileus a layer of vesiculose cells
several cells deep and with pale ochraceous to cinnamon walls next to the hyphae
of the subcutis. Clamp connections present.
Type locality. Lower Tahoma Creek, Mt. Rainier National Park, Washington.
Habit and habitat. Gregarious under alder.
Distribution. Michigan and Washington.
Observations. This species is peculiar because of the coloration of the pileus
and the lack of reddish tones in the gills after spores have formed. The pale bister
(yellow-brown) cheilocystidia are also unusual.
Material examined. Michigan: Potter 7127, 7139, 7163; Smith 34124. Washington: Imshaug 1309; Smith 29417, 29488, 29514, 29515, 29531, 29640, 29641,
29821, 29923, 30168, 30221, 30227, 30392 (Type) 31507.
190. Psathyrella affinis A. H. Smith, sp. nov.
Pileus 1-2.5 cm latus, obtuse conicus demum expanso-umbonatus, fuscobrunneus, fibrillosus, glabrescens, demum rugulosus; lamellae brunneolae demum
violaceo-griseae, latae, demum subdistantes; stipes 1-3 (-4) cm longus, 1-1.5
(-2) mm crassus, pallidus, deorsum brunneus, fibrillosus, glabrescens; sporae