The North American species of Psathyrella.

1972]

PSATHYRELLA

261

7. Stipe 1.5-3 cm long, 1-2 mm thick, darker below; veil rudimentary; gill edges not
known to be pink in age. 225. P. potteri.
7. Not as above. 8
8. Stipe soon discolored over lower part. 226. P. pruinosipes.
8. Stipe remaining white to pallid throughout. 9
9. Pileus 6-12 mm broad; lamellae pale grayish brown when young. 227. P. prona.
9. Pileus 1-4 cm broad; lamellae white to pallid when young. 10
10. Pileus violaceous-brown fading to vinaceous gray. 228. P. argentata.
10. Pileus dark rusty brown fading to pale tan. 11
11. Pileus with only the margin fibrillose at first. 229. P. equina.
11. Pileus and stipe with copious fibrils. 230. P. hirta.
219. Psathyrella galericolor A. H. Smith, sp. nov.
Pileus 1-2.5 cm latus, conicus vel convexus, glaber, fulvus; lamellae subdistantes, latae, brunneolae demum fumoso-fulvae; stipes 2-4 cm longus, 1.5-2.5
mm crassus, albidus, deorsum demum melleibrunneus, sparse fibrillosus, glabrescens; sporae 7-9 x 4-5 A; pleurocystidia 42-60 x 9-14 (-16) /, anguste fusoideoventricosa, obtusa vel subacuta; cheilocystidia saepe subvesiculosa; fibulae
adsunt. Typus. Smith 43054 (MICH); legit prope Cross Village, Michigan.
Pileus 1-2.5 cm broad, obtuse when young, expanding to broadly conic or
convex, surface glabrous, moist and hygrophanous, marginal area pale tawny and
edge fringed with fibrils for a time from the rudimentary veil, disc tawny or
darker, fading to ochraceous-tan. Context thin and fragile.
Lamellae subdistant, broad, adnate, pallid brownish becoming dingy tawny
and finally duller from the spores, edges pallid.
Stipe 2-4 cm long, 1.5-2.5 mm thick, equal, hollow, fragile with a patch of
radiating mycelium at the base, white at first but dingy honey brown over lower
area in age, faintly fibrillose becoming glabrous.
Spores 7-9 x 4-5 /, smooth, apical pore scarcely evident, apex only very
obscurely truncated in a few, shape in face view fairly broadly elliptic to
obscurely ovate, in profile somewhat bean-shaped to obscurely inequilateral, color
in KOH ochraceous tawny, slowly darkening slightly, in Melzer's pale tawny;
wall about 0.2 u thick.
Basidia 4-spored, narrowly clavate, 20-24x 7-9 I, hyaline in KOH. Pleurocystidia 42-60x9-14 (-16) A, narrowly fusoid-ventricose with the apex obtuse to
subacute and when first revived in KOH with particles of coagulated material
adhering near the apex, thin-walled but wall in KOH refractive to apex where
it is very thin and often bursts in KOH mounts; cell content not distinctive
in KOH or in Melzer's. Cheilocystidia mostly subvesiculose to clavate and
20-32 x 9-18 t, some fusoid-ventricose cells 28-36 x 8-12 / also present.
Gill trama regular, hyphae with walls hyaline to pale rusty in KOH. Pileus
with a cuticle of inflated cells 2-3 cells deep, walls hyaline to ochraceous in KOH
or near the subcutis tawny wall thickenings evident. Hyphae of subcutis with
tawny incrusted pigment and wall thickenings (mostly near the septa). Clamps
present.
Type locality. Wilderness State Park, Emmet County, Michigan.
Habit and habitat. On piles of porcupine dung, gregarious.
Distribution. Known only from the type locality.
Observations. The pale ochraceous-tawny spores slowly darkening to dull
cocoa-color in KOH, the "Galerina-like" aspect, practical lack of a veil (no
small buttons were available for study), and the long narrow pleurocystidia are
distinctive. The species, actually, appears to be closely related to P. fulvescens.