The North American species of Psathyrella.

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MEMOIRS OF THE NEW YORK BOTANICAL GARDEN

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Lamellae broad, broadly adnate, close at first, subdistant in age, pallid buff
becoming dark bister and finally nearly fuscous, edges even.
Stipe 3-6(-8) cm long, 2-3 mm thick, equal, hollow, white, fragile, at first
with scattered fibrils in squamules or patches but soon glabrous, apex faintly
pruinose.
Spores 7-9 x 4-4.8 at, smooth, apical pore distinct and apex somewhat truncated
(if the lens-membrane over the pore collapses), shape in face view elliptic or
nearly so, in profile obscurely inequilateral to subelliptic, color in KOH coffeecolor becoming chocolate-color (a violaceous component develops), reddish tawny
in Melzer's, wall about 0.3, thick.
Basidia 17-22 x 7-9 /A, 4-spored, hyaline in KOH, short-clavate. Brachybasidioles present in age (at least the basidioles become more inflated in age).
Pleurocystidia scattered (26-) 36-50 x 9-14 a, fusoid-ventricose, apex subacute to
obtuse, wall thin, smooth and hyaline, content of cell not distinctive in either KOH
or Melzer's. Cheilocystidia similar to pleurocystidia; a few clavate, hyaline, thinwalled cells also present. Caulocystidia versiform (Fig. 441), thin-walled, smooth,
hyaline, content not distinctive.
Gill trama interwoven, dull vinaceous-brown in KOH. Pileus trama vinaceousbrown in KOH, fading, some pigment incrustations and wall thickenings present
especially near the cross walls. Pileus cuticle of hyaline vesiculose cells about
2 deep, their walls thin, smooth and hyaline, cell content not distinctive. Clamp
connections present. No distinctive reaction on any tissue in Melzer's.
Type locality. Europe.
Habit and habitat. Solitary to gregarious on debris in mixed conifer-hardwood
forests, late summer and fall.
Distribution. United States: Michigan, Oregon, Washington. Canada: Ontario.
Observations. This species answers well to the features of distinction in the
Friesian descriptions. However, the species apparently does not have a clear and
widely accepted concept in Europe by present-day mycologists. Hence the name
is used here tentatively.
Material examined. UNITED STATES. Michigan: Potter 4155, 8667; Smith
28663, 28665, 33331, 33634, 33745, 33814, 33817, 34010, 34130, 34131. Oregon:
Smith 20082. Washington: 29767, 29768. CANADA. Ontario: Smith 4480.
192. Psathyrella payettensis A. H. Smith, sp. nov.
Pileus 1.5-2.5 cm latus, late conicus, albo-squamulosus glabrescens, sordide
cinnamomeus; lamellae pallide demum fusco-brunneae, latae, subdistantes; stipes
3-4.5 cm longus, 1.5-3 cm crassus, albidus, deorsum floccosus, glabrescens, ad
basem demum sordide brunneus; sporae 7-8 x4.5-5 /; pleurocystidia 38-52
(-60) x 9-16 ju, fusoide ventricosa, obtusa vel subacuta; fibulae adsunt. Typus.
Smith 70160 (MICH); legit prope Warren, Idaho.
Illust. Text Figs. 442-445.
Pileus 1.5-2.5 cm broad, obtusely conic and margin straight, becoming broadly
conic, surface at first covered by minute white superficial squamules from the
outer veil, soon glabrous, margin merely fringed with fibrils at first, surface moist
and hygrophanous, near "Sayal brown" (dingy cinnamon) or slightly darker at
first, paler on the faintly striate margin. Context exceedingly fragile, odor and
taste not distinctive, with FeSO4 no color change.
Lamellae pallid brownish becoming "wood brown" or darker, close to subdistant, broad, seceding, edges even.