The North American species of Psathyrella.

1972]

PSATHYRELLA

163

Material examined. Michigan: Smith 34013. Washington: Imshaug 2070;
Smith 29142 (Type), 29148.
119. Psathyrella fallax A. H. Smith, sp. nov.
Pileus 1-3 cm latus, demum campanulatus vel late convexus, ad marginem
sparse appendiculatus, glaber, cinnamomeus, nitens; lamellae pallide cinnamomeae demum fusco-brunneae, confertae, latae, secedentes; stipes 3-8 cm longus,
1.5-3.5 mm crassus; fragilis, pallidus, deorsum demum sordide alutaceus; sporae
7-9x4-5 u. Pleurocystidia 36-50x9-15,u, fusoideo-ventricosa, obtusa; fibulae
adsunt. Typus. Smith 43322 (MICH); legit prope Mackinaw City, Michigan.
Pileus 1-3 cm broad, obtusely conic when young, expanding to obtusely
campanulate or convex, margin at first slightly appendiculate from the veil,
glabrous otherwise but small buttons covered by a thin fibrillose veil, color a rich
cinnamon-brown and shiny (with a clean appearance), fading to dingy buffy tan
but drying a dull cinnamon-tan. Context dark brown, thin, fragile and lacking
a distinctive odor.
Lamellae dingy cinnamon when young, becoming dark cinnamon before being
clouded chocolate-brown as the spores mature, drying dark vinaceous-brown,
close, moderately broad, adnate-seceding, edges even.
Stipe 3-8 cm long, 1.5-3.5 mm thick, equal, slender, fragile, whitish at first
but discoloring to tan below, coated with white veil fibrils at first but glabrescent,
apex pruinose.
Spores 7-9x4-5 ~, smooth, apex truncate from a small pore, shape in face
view almost perfectly narrowly ellipsoid varying to oblong, in profile obscurely
clouded chocolate-brown as the spores mature, drying dark vinaceous-brown,
finally chocolate-brown, in Melzer's tawny, wall about 0.3 IL thick.
Basidia 4-spored. Pleurocystidia 36-50x9-15 /p, fusoid-ventricose with an
obtuse apex, wall thin, smooth and hyaline (or rarely with dried coagulated
material adhering to it near apex), cell content not distinctive. Cheilocystidia
similar to pleurocystidia but neck typically shorter, apex obtuse to rounded;
clavate cells also present. Hyphae of trama rusty brown in KOH, with incrusting
pigment. Cuticle of pileus a layer 2-3 cells deep of vesiculose hyaline to
ochraceous cells with smooth, thin walls. Clamp connections present.
Type locality. Wilderness State Park, Emmet County, Michigan.
Habit and habitat. Gregarious on chip-dirt, September.
Distribution. Michigan.
Observations. This species resembles P. obtusata but has an appendiculate
pileus margin at first, strikingly elliptic spores in face view which are coffeecolored in KOH, and the pleurocystidia are obtuse enough to approach being
utriform in shape.
Material examined. Michigan: Smith 43322 (Type), 62163.
120. Psathyrella tahquamenonensis A. H. Smith, sp. nov.
Pileus 2-4 cm latus, demum campanulatus vel plano-umbonatus, glaber, ad
marginem appendiculatus (denticulatus), griseo-argillaceus deinde subincarnatus; lamellae confertae, latae, brunneae demum purpureo-brunneae; stipes 3-5 cm
longus, 3-5 mm crassus, fragilis, albidus, deorsum fibrillosus, glabrescens; sporae
7-9 x 4-4.5 /; pleurocystidia 40-56 x 10-16 u, fusoide ventricosa, subacuta; fibulae
adsunt. Typus. Smith 61022 (MICH); legit Tahquamenon Falls State Park,
Michigan.