The North American species of Psathyrella.

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MEMOIRS OF THE NEW YORK BOTANICAL GARDEN

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Illust. Text Figs. 117-119.
Pileus 2.5-4 cm broad, nearly plane when mature, obtuse at first, then convex,
glabrous and moist, hygrophanous, at first a grayish honey-color, fading to grayish buff; margin appendiculate with small fragments of the veil at first. Context
thin but not markedly fragile, odor and taste not recorded.
Lamellae grayish pallid becoming dark grayish brown ("hair brown"), close,
narrow, adnate-seceding, edges even and pallid.
Stipe short, 2-4 cm long, 2-4 mm thick at apex, pallid and more or less naked
above, lower down thinly coated with grayish pallid fibrils, as dried with a distinct
"sand bulb" at the base as a result of shrinkage of tissue above the bulb.
Spores 7-8 x 3.5-4 x 4-4.6 a, smooth, apical pore distinct, at least a fair number
slightly compressed, shape in face view ovate to elliptic, in profile somewhat beanshaped to oblong, rarely with a slight medial constriction, color in KOH dull
cocoa-color but slowly darkening, in Melzer's tawny red, wall 0.2 p.
Basidia 4-spored, 17-22 x 5-7 a, clavate, hyaline in KOH. Pleurocystidia not
found. Cheilocystidia 34-47x9-14 a, utriform to capitate, thin-walled, smooth,
hyaline in KOH, content not distinctive in KOH or Melzer's, some vesiculose cells
also present. Caulocystidia similar to but larger than cheilocystidia, rare.
Pileus cuticle a layer of vesiculose cells 1-2 deep, the walls thin and hyaline
to yellowish hyaline, smooth, content not distinctive. Hyphae of the subcuticular
zone dingy cinnamon in KOH, the walls smooth or practically so. Clamps present.
No distinctive reactions in Melzer's observed.
Type locality. University of Michigan Biological Station, Cheboygan County,
Michigan.
Habit and habitat. Gregarious on sand at the edge of a woods, July.
Distribution. Known only from the type locality.
Observations. The distinctive features of this species are the slightly compressed spores, the color of the pileus (which is grayer than that of P. candolleana
in young stages), the habitat on sand, the grayish pallid fibrils on the stipe, and
the gray-brown gills when mature. They lack a violaceous tone. As dried the gills
are dull cocoa-color.
43. Psathyrella rupchandii A. H. Smith, sp. nov.
Pileus 1-3 cm latus, obtuse conicus, demum late conicus, glaber, ad marginem
appendiculatus, fulvus; lamellae brunneolae, demum fulvae, angustae, confertae,
adnatae; stipes 5-8 cm longus, 3-3.5 mm crassus, albidus, glabrescens; sporae
7-8 x 4-4.5 i, in "KOH" cacaocolor demum subfuscae; pleurocystidia nulla;
cheilocystidia clavata, subcylindrica vel fusoide ventricosa; fibulae adsunt. Typus.
Smith 78343 (MICH); legit Rup Chand, Ann Arbor, Michigan.
Illust. Text Figs. 120-122.
Pileus 1-3 cm broad, obtusely conic, expanding to broadly conic, dark rusty
brown ("Mars brown") moist, fading to pale tan ("pinkish buff") on disc first,
margin quite irregular and at first decorated with appendiculate patches of pallid
veil remnants, surface at first thinly fibrillose from the veil but glabrescent when
still only partly expanded. Context thin, fragile, concolorous with pileus when
either moist or faded, odor and taste not distinctive.
Lamellae rusty brown like the pileus when mature, merely dull brownish when
young, crowded, narrow, adnate, edges even.
Stipe 5-8 cm long, 3-3.5 mm thick, equal, white, not discolored in old ones,
at first with scattered fibrils from the veil but soon glabrescent.