The North American species of Psathyrella.

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MEMOIRS OF THE NEW YORK BOTANICAL GARDEN

[VOL. 24

brown" moist, fading only slightly and near "warm sepia" when dried. Context
fragile, very thin, odor and taste not recorded.
Lamellae adnate, close, narrow, pallid cinnamon becoming more or less cocoacolor at maturity, edges even, whitish.
Stipe 3-4 cm long, 1-2 mm thick, equal, hollow, fragile, white, at first with
scattered white flecks of fibrils from the veil but soon glabrous.
Spores reddish cocoa-color in mass, 7.5-9 x 4.5-5.5 a, smooth, apical pore inconspicuous and apex not truncate, shape in face view broadly elliptic to slightly
oval, in profile bean-shaped to obscurely inequilateral, color in KOH dull cocoacolor but slowly darkening slightly and clouded grayish, in Melzer's dull tawny,
wall about 0.4,u thick.
Basidia 4-spored, 14-20 x 8-9 u, hyaline in KOH, clavate. Pleurocystidia
abundant, 38-46 x 9-15 g, fusoid-ventricose, apex obtuse to rounded and usually
with incrusting material, wall about 0.5 / thick (many cystidia remain collapsed),
wall becoming dingy vinaceous-brown to avellaneous in KOH. Cheilocystidia
32-48x 8-14 g, fusoid-ventricose, often smooth, apex obtuse; some small clavate
to vesiculose elements also present.
Gill trama rusty brown revived in KOH. Pileus trama rather bright yellowish
to cinnamon-brown but gradually becoming duller, walls smooth or with pigment
thickenings near the septa. Cuticle of the pileus formed by a layer of vesiculose
cells 2-3 deep and with pale cinnamon walls (as seen in groups), walls smooth.
Cell content not distinctive in KOH or Melzer's. Clamps present.
Type locality. Ann Arbor, Michigan.
Habit and habitat. Solitary on wet humus under brush.
Distribution. Known only from the type locality.
Observations. The pleurocystidia have thinner walls than in P. olympiana,
the color of the spore deposit is redder and the young pileus is ochraceous-tawny.
216. Psathyrella sharonensis A. H. Smith, sp. nov.
Pileus 10-40 mm latus, late convexus, glaber, dilute griseo-brunneus; lamellae
confertae latae, pallide fulvo-cinnamomeae demum fumoso-cinnamomeae; stipes
1-5 cm longus, 1-4(-5) mm crassus, subcinereus, demum sordidus; sporae 6-7x
3.5-4 [; pleurocystidia 28-40 x 8-12 a, fusoide ventricosa, ad apicerum, rotundata;
fibulae adsunt. Typus. Smith 64638 (MICH); legit prope Manchester, Michigan.
Illust. P1. 72, fig. c; Text Figs. 497-499.
Pileus 10-40 mm broad, convex, becoming broadly convex to nearly plane,
glabrous, moist, hygrophanous, watery gray-brown when young, becoming darker
and more rusty brown as spores mature, when moist translucent striate about half
way to the disc, fading in streaks and patches causing surface to appear silvery
in age, when faded near pinkish buff. Context very thin, fragile, odor and taste
mild, no reaction with KOH or FeSO4.
Lamellae close, adnate-seceding, moderately broad, pale rusty cinnamon becoming "Mars brown" and retaining a dark rusty brown tone on drying, edges
even.
Stipe 1-5 cm long, 1-4(-5) mm thick, equal or apex enlarged slightly, grayish
white, naked to faintly fibrous-striate, apex naked or nearly so, color brownish
throughout but in age not typically discoloring from the base upward.
Spores 6-7 x 3.5-4 /, smooth, apical pore minute, shape in face view ovate to
almost angular-ovate, some obscurely triangular, in profile obscurely inequilateral
to subelliptic, dull rusty brown when revived in KOH but slowly changing to
dark chocolate-color, dull tawny-red in Melzer's, wall about 0.2 M thick.