The North American species of Psathyrella.

1972]

PSATHYRELLA

315

prongs, 38-52 x 10-15 gA, wall thin, smooth and hyaline, cell content not distinctive. Cheilocystidia of two types, the first fusoid-ventricose, hyaline in KOH and
thin-walled, with obtuse to subacute apex, 28-31 x 9-12 /; the second clavate to
ellipsoid and slightly yellowish in KOH, the wall very slightly thickened in some.
Caulocystidia more or less resembling the pleurocystidia but variable in size.
Gill trama regular, of somewhat inflated cells, dull brown in KOH but fading.
Pileus trama of floccose hyphae interwoven and pale to dark cinnamon-brown in
KOH, fading on standing, pigment incrustations clearly evident on the hyphae
of immature pilei. Cuticle of pileus formed by a layer of globose and often
pedicellate cells one cell deep arranged in a rather loose palisade, the walls thin
and in KOH yellowish to hyaline, cell content not distinctive. Clamp connections
present.
Type locality. Lake Mills, Olympic National Park, Washington.
Habit and habitat. Gregarious on debris in an alder flat.
Distribution. Oregon, Washington.
Observations. The distinctive features of this species are the practical absence
of a veil, the cartilaginous stipe, the pink tints which develop in age on faded pilei,
the loose palisade of cells forming the cuticle of the pileus, and the medium-large
spores.
Material examined. Oregon: Smith 24548. Washington: Smith 14162 (Type).
285. Psathyrella barlowiana A. H. Smith, sp. nov.
Pileus 10-15 mm latus, conicus, glaber, cinnamomeo-brunneus; lamellae brunneolae, demum brunneo-violaceae, subdistantes, latae; stipes 4-7 cm longus,
1-2 mm crassus, pallidus; deorsum demum avellaneus; fibrillosus glabrescens;
sporae 9-12 x 5-6.5 u; pleurocystidia 46-62 x 6-12 t/, anguste fusoideo-ventricosa;
fibulae adsunt. Typus. Smith 24284 (MICH); legit prope Government Camp,
Mt. Hood, Oregon.
Illust. Text Figs. 611-613.
Pileus 10-15 mm broad, obtusely conic and expanding merely to broadly conic,
glabrous except for a thin fringe of fibrils along the margin which is soon evanescent, moist and hygrophanous "cinnamon-brown" when young and moist, becoming grayer as spores mature, translucent-striate at first, fading to near "cinnamonbuff," atomate when faded. Context very thin and fragile, concolorous with
surface, odor and taste not distinctive.
Lamellae dull brownish, then violaceous-drab ("benzo brown"), subdistant,
2 tiers of lamellulae, ascending but bluntly adnate, readily seceding, broad
(3 mm), edges even but whitish.
Stipe 4-7 cm long, 1-2 mm thick, equal, tubular, fragile, whitish above, sordid
avellaneous below, lower part decorated with numerous white fibrils from the
remains of the thin partial veil, pruinose above.
Spores 9-12 x 5-6.5 I/, smooth, apex truncate from a distinct apical pore, shape
in face view ovate to elliptic, in profile obscurely inequilateral to subelliptic, color
in KOH medium chocolate-color but when first mounted dull cocoa-color, reddish
fulvous in Melzer's, wall about 0.6 p thick.
Basidia 4-spored, 18-22 x 9-11 t/, clavate-subcapitate, hyaline in KOH. Pleurocystidia 46-62 x 6-12 /l, narrowly fusoid-ventricose, neck elongate and apex subacute, wall smooth, hyaline and thin, cell content not distinctive in KOH or
Melzer's. Cheilocystidia abundant, 20-38 x 6-10 /J, fusoid-ventricose to clavate,