The North American species of Psathyrella.

1972]

PSATHYRELLA

383

shaped, color in KOH cocoa-color becoming chocolate-gray, in Melzer's tawny,
wall about 0.3,/ thick.
Basidia 4-spored, 18-28x8-11 I, clavate, hyaline in KOH. Pleurocystidia
50-80x 10-16 [, elongate-fusoid-ventricose, apex obtuse to subacute, wall thin,
smooth and hyaline, content not distinctive. Cheilocystidia 34-50 x10-14 p,
fusoid-ventricose to clavate, thin-walled, smooth or with some adhering debris,
content of some (in limited areas) reddish cinnamon in KOH.
Pileus cuticle of vesiculose and pear-shaped pedicellate cells, the layer 1-4 cells
deep, wall near base cinnamon in KOH, near apex hyaline or nearly so (or upper
layer very pale and area near subcutis cinnamon-red and some cells filled with
cinnamon-red pigment). Hyphae of the pileus trama reddish-cinnamon in KOH
or vinaceous-cinnamon, with inconspicuous incrustations except for wall thickenings near or at the septa. Clamp connections present.
Type locality. Mt. Hood National Forest, Oregon.
Habit and habitat. Gregarious on debris of mixed conifer and deciduous forest,
September.
Distribution. Oregon.
Observations. This is a very readily identified species because of the extremely
long pleurocystidia and colors of the basidiocarp which approximate those of the
P. frustulenta group. The pigment noted in the cheilocystidia in places along the
gill edge may be distinctive, but it was not found in young specimens.
357. Psathyrella angusticystis A. H. Smith, sp. nov.
Pileus 1-2.5 (-3) cm latus, ovatus demum campanulatus; lacteo-albus demum
pallide fusco-brunneus; lamellae latae, confertae demum subdistantes, fuscobrunneae; stipes 3-5 cm longus, 2-2.5 mm crassus, albus demum sordide griseus
sparse fibrillosus, glabrescens; sporae 7-9 x 4.5-5 u; pleurocystidia 38-60 x 8-12 u,
anguste fusoideo-ventricosa, elongata; fibulae adsunt. Typus. Smith 43146
(MICH); legit prope Mackinaw City, Michigan.
Illust. P1. 86, fig. b; Text Figs. 807-809.
Pileus 1-2.5 (-3) cm broad, oval and expanding to obtusely campanulate,
surface glabrous, moist, hygrophanous, watery tan ("cinnamon-buff") young,
becoming milky white before maturity, when mature avellaneous to wood brown,
translucent-striate, with a fringe of fibrils on the margin as the veil breaks but
all traces soon vanishing, in age and when faded pale pinkish buff. Context very
soft and fragile, odor and taste not distinctive.
Lamellae broad, close to subdistant, ascending-adnate, becoming ventricose,
near wood brown when mature, edges even.
Stipe 3-5 cm long, 2-2.5 mm thick, equal, fragile, hollow, white, sparsely
fibrillose from the veil at first, watery grayish in age and apex pruinose,
glabrescent below.
Spores 7-9 x 4.5-5 A, smooth, apical pore very inconspicuous, in face view oval
to elliptic to suboblong, in profile view obscurely bean-shaped to obscurely
inequilateral, color in KOH cocoa-color and not darkening readily, (pale cinnamon in water mounts when fresh), in Melzer's pale reddish tawny, wall about
0.2 u thick.
Basidia 4-spored, short-clavate, 8-10,u wide when sporulating. Pleurocystidia
38-60 x 8-12 JL, subcylindric to narrowly ventricose with an elongated neck and
obtuse apex, very abundant, smooth, thin-walled, hyaline or wall weakly yellow