The North American species of Psathyrella.

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MEMOIRS OF THE NEW YORK BOTANICAL GARDEN

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mixed with vesiculose cells, their walls yellowish-hyaline in KOH, the cell content
not distinctive in KOH or Melzer's. Hyphae of the subcuticular zone weakly
brownish in KOH, thin-walled, smooth. Clamps present. No distinctive reactions
observed for any tissue as mounted in Melzer's.
Type locality. Upper Priest River, Boundary County, Idaho.
Habit and habitat. Cespitose on chip-dirt, October.
Distribution. Idaho.
Observations. The pointed pleurocystidia with slightly thickened walls, the
elongate caulocystidia, the white veil and pallid pileus along with the small spores
are distinctive.
Material examined. Idaho: Smith 73875 (Type), 74105.
354. Psathyrella ophirensis A. H. Smith, sp. nov.
Pileus 1-4 cm latus, late conicus, glaber, subspadiceus vel sordide cinnamomeus; lamellae confertae, latae, brunneolae demum griseo-cacaocolor; stipes
valde caespitosus, 6-12 cm longus, 2-4 mm crassus, albidus, deorsum fibrillosus;
velum sparsum; sporae 7-9 x 4.5 (-5) pu pleurocystidia 28-42 x 7-12 i, fusoide ventricosa vel subutriformia; fibulae adsunt. Typus. Smith 51783 (MICH); legit
prope Ophir, Colorado.
Illust. P1. 87, fig. a; Text Figs. 790-792.
Pileus 1-4 cm broad, oval to obtusely conic, expanding to broadly conic,
surface moist and hygrophanous but none of them striate, "buckthorn brown" to
"Sayal brown" when moist, pinkish buff to cinnamon-buff faded, glabrous except
when very young and then only with scattered fibrils near the margin. Context
thin, fragile, concolorous, odor none, taste not distinctive-merely slightly
disagreeable to mild.
Lamellae crowded, adnate, narrow to only moderately broad, pallid brownish
at first, dull cocoa-color when mature but in age grayer (near cinnamon-drab).
Stipe in massive clusters held together by numerous rhizomorphs and other
mycelium (no pseudorhiza present), 6-12 cm long, 2-4 mm thick, white throughout and unchanging, base woolly-fibrillose, apex fibrillose-pruinose; veil white,
thin, leaving scattered fibrils on lower part of stipe but not leaving a distinct zone
at the point where it breaks.
Spores 7-9 x 4-4.5 (-5) fu, smooth, with an apical hyaline lens-shaped cap causing apex to appear truncate, shape in face view elliptic, in profile elliptic to
obscurely bean-shaped (ventral line straight more or less), color in KOH grayish
brown and not darkening appreciably, in Melzer's bright reddish tawny, wall
about 0.2 p thick.
Basidia 4-spored, 22-28x6-8 ux, clavate, hyaline. Pleurocystidia scattered,
28-42x7-12 /A, fusoid-ventricose with obtuse apex to subutriform, wall thin,
smooth, cell content not distinctive in KOH or Melzer's. Cheilocystidia smaller
than pleurocystidia but otherwise approximately similar to more fusoid. Caulocystidia near apex similar to cheilocystidia, none found a centimeter from the
apex.
Pileus cuticle cellular, 1-2 cells deep, cells 15-40 f wide, some pedicellate with
wall of pedicel thin but cinnamon in color (in KOH), subcuticular zone cinnamon
in KOH but fading. In Melzer's all tissues non-amyloid (yellowish), some fine
hyaline globules noted in the mount. Clamp connections present.
Type locality. Ophir Valley, Ophir, San Miquel County, Colorado.