The North American species of Psathyrella.

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MEMOIRS OF THE NEW YORK BOTANICAL GARDEN

[VOL. 24

220. Psathyrella minima Peck, Rep. N. Y. State Mus. 41: 70. 1888.
Pileus 1-4 mm broad, margin appressed against the stipe at first, cap conic
and becoming nearly campanulate, when young appearing frosted or minutely
pubescent under a lens from pileocystidium-like hairs, soon glabrous, "buckthorn
brown" to "cinnamon-buff," hygrophanous and fading to pale pinkish buff. Context very delicate and membranous.
Lamellae bluntly adnate, distant (5-7 reach the stipe, 1 tier of lamellulae),
broad, pallid honey-color becoming more or less wood brown from the spores,
edges even.
Stipe up to 20 mm long, filiform, pallid watery gray to pale honey-color,
flecked with white tufts (of caulocystidia?), no veil observed.
Spores 6-8 x 3-4 A, cocoa-color in H20 mounts when fresh, darker revived in
KOH.
Basidia 4-spored, 10-12 x 6-7 lu, rather short and fat. Pleurocystidia rare and
similar to the cheilocystidia. Cheilocystidia 20-30 x 6-10 A, abundant, thin-walled,
smooth, fusoid-ventricose, apex subacute, hyaline in KOH. Gill trama and pileus
trama of vesiculose to ellipsoid cells. Cuticle of pileus a palisade of globosepedicellate cells with fusoid-ventricose acutely pointed projecting pileocystidia
20-28 x 6-9 1A, projecting, cuticular cells 15-20 /u wide.
Type locality. Adirondack Mountains, New York.
Habit and habitat. Scattered to gregarious on deer dung.
Distribution. Idaho, Michigan, New York, Washington.
Observations. The exceedingly small delicate basidiocarps make preservation
by drying almost impossible.
Material examined. Idaho: Smith 54162, 54447, 71071. Michigan: Smith
23398, 37027, 37071. New York: Peck's type.
221. Psathyrella pseudolimicola A. H. Smith, sp. nov.
Pileus 1-3 cm latus, late convexus, glaber, sordide cinnamomeus; lamellae
brunneolae demum violaceo-fuscae; stipes 3-8 cm longus, 2-3.5 mm crassus,
albidus demum sordidus, sparse fibrillosus, glabrescens; sporae 8.5-11 x4.5-5
(12 x 6) i; pleurocystidia 36-45 (-50) x 9-15 A, utriformia vel ventricoso-rostrata,
ad apicerum saepe subcapitata; fibulae adsunt. Typus. Smith 65850 (MICH);
legit prope Riggins, Idaho.
Illust. Text Figs. 502-505.
Pileus 1-3 cm broad, obtuse to convex, expanding to nearly plane, surface
moist and hygrophanous, dingy "Verona brown" to pale dull cinnamon-brown
when fresh, fading to cinnamon-buff or finally pale pinkish buff on margin, disc
remaining cinnamon-buff, striate when moist, decidedly atomate when faded;
margin at first decorated with a fringe or patches of pallid veil material,
glabrescent.
Lamellae pallid brownish when young, when mature "benzo brown" (grayish
violaceous-brown), close, broadly adnate, broad, horizontal, edges whitish.
Stipe 3-8 cm long, 2-3.5 mm thick, equal, fragile, hollow, white and scarcely
discoloring, only faintly fibrillose when very young, soon naked except for the
base which is fibrillose-squamulose from white fibrils.
Spores 8.5-11x 4.5-5 (-12 x 6) pA, smooth, apical pore distinct, shape in face
view elliptic to slightly ovate, in profile subelliptic, wall about 0.3 p thick, color
in KOH dark chocolate-color, in Melzer's tawny-red.