The North American species of Psathyrella.

158

MEMOIRS OF THE NEW YORK BOTANICAL GARDEN

[VOL. 24

Illust. Text Figs. 272-274.
Pileus 2.5-5 cm broad, obtusely conic, expanding to campanulate and finally
nearly plano-umbonate, surface moist and hygrophanous, glabrous except for
patches of matted fibrils along the margin or hanging from it, color dark honeycolor when moist and fading to pale pinkish buff. Context thin but relatively
firm, cartilaginous, odor and taste not recorded.
Lamellae narrow, close, adnate, pallid to near cinnamon-buff but finally nearly
drab (gray), edges even.
Stipe 4-6 cm long, 3-5 mm thick, relatively cartilaginous, hollow, whitish
glabrous or nearly so, pruinose above, base white-strigose.
Spores 8-10x 4.5-5.5 x 5.5-6.5 /, smooth, apical pore present but very inconspicuous, shape in face view distinctly ovate to elliptic, in profile obscurely
inequilateral, subelliptic or bean-shaped (less frequently), color in KOH becoming dark coffee color to chocolate-brown, in Melzer's reddish tawny, wall about
0.6 M thick.
Basidia 4-spored, 26-29x8-10 /, clavate, hyaline in KOH. Pleurocystidia
scattered, 48-62 x10-16 I, ventricose with obtuse apex or subcapitate, some
branched near apex or with several protuberances, wall thin, smooth and hyaline,
content not distinctive in either KOH or Melzer's. Cheilocystidia mostly clavate,
ovate-pedicellate, vesiculose or somewhat fusoid-ventricose with obtuse to
rounded apex, thin-walled, hyaline to yellowish, smooth. Caulocystidia more or
less similar to the cheilocystidia, rare to scattered as far as observed.
Gill trama regular, tinged cocoa-color in KOH but soon fading, color in the
cell walls. Pileus cuticle an irregular layer of vesiculose cells about 2 deep, their
walls thin, smooth and hyaline, content of cells not distinctive in either KOH or
Melzer's. Hyphae of the context in young pilei cocoa-colored as revived in KOH
but soon fading, in old pilei nearly hyaline, walls smooth. Clamps present. No
distinctive reactions on any tissue as revived in Melzer's.
Type locality. Beaver Creek, Mt. Hood National Forest, Oregon.
Habit and habitat. Gregarious on rotten conifer wood, October.
Distribution. Known only from type locality.
Observations. This species reminds one of P. candolleana but differs in having
pleurocystidia and in the features of the spores.
114. Psathyrella rugulosa A. H. Smith, sp. nov.
Pileus 2-4 cm latus, convexus, demum late convexus; ad marginem dente
appendiculatus, subhepaticolor; lamellae latae, ventricosae confertae ("auburn")
laete brunneo-fulvae; stipes 3-5 cm longus, 3-5 mm crassus, cavus, albidus,
deorsum tactu brunnescens; sporae 7-9 X 4-5 I; pleurocystidia 38-50 x 9-14 i,
obtusa vel subacuta; fibulae adsunt. Typus. Hesler 17027 (MICH); legit prope
Clingman's Dome, Tennessee (Great Smoky Mountains National Park).
Pileus 2-4 cm broad, convex to obtuse, expanding to broadly convex or slightly
umbonate, margin dentate-appendiculate with patches of white veil material, dark
reddish brown moist ("warm sepia"), pale tan ("pinkish buff") faded, conspicuously radially rugulose, striate when moist. Context thin, fragile, hygrophanous,
concolor with pileus, odor and taste not distinctive.
Lamellae adnate-decurrent, seceding, medium broad and ventricose, close,
"auburn" (bright rusty brown), edges serrulate.
Stipe 3-5 cm long, 3-5 mm thick, hollow, equal or equal down to an enlarged
base, white and shining but showing brown in the lower portion where it is covered
with scattered fibrils, apex pruinose.