The North American species of Psathyrella.

1972]

PSATHYRELLA

407

Stipe 1-5 cm long, 1-2 mm thick, equal, fragile, hollow, pallid at first, becoming brownish over all, slightly pruinose above, scarcely mycelioid at base.
Spores 7-8x4-4.5,/, smooth, apical pore very inconspicuous and spore apex
not truncate, shape in face view narrowly elliptic varying to slightly ovate or to
oblong, in profile subelliptic varying to slightly bean-shaped or to obscurely
inequilateral, color in KOH cocoa-brown (rather dark) at first, slowly becoming
dark chocolate-color, in Melzer's reddish tawny to pale bay, wall about 0.3 / thick.
Basidia 14-18 x 7-9 E/, 4-spored, clavate, hyaline in KOH. Pleurocystidia
scattered, 28-48 x 9-14 /u, fusoid-ventricose, apex obtuse, wall thin, hyaline
and smooth or with granular material adhering over apical region, cell content not
distinctive. Cheilocystidia fusoid-ventricose to vesiculose, the former similar to
the pleurocystidia, the latter 12-18 / wide and hyaline to yellowish in KOH.
Caulocystidia versiform (Fig. 856).
Gill trama ochraceous-tawny in KOH, the color in the wall, fading on standing. Pileus trama cinnamon to ochraceous-tawny, fading on standing, walls with
incrusted pigment especially near the septa. Cuticle of pileus a layer of vesiculose
to pear-shaped cells 1-2 cells deep, not organized into a distinct palisade, walls
hyaline to pale cinnamon in KOH, fading on standing. Clamp connections present.
Type locality. Pole Mountain, near Laramie, Wyoming.
Habit and habitat. Gregarious on soil in wet areas.
Distribution. Michigan, New Mexico, Wyoming.
Observations. In the type the basidia are short and fat, and it is difficult to
state whether brachybasidioles are present at maturity or not-the difference is
not great.
Material examined. Michigan: Ammirati 1602. New Mexico: Barrows 780.
Wyoming: Smith 34616 (Type) 34653, 34698, 34717, 34829, 34833, 35202, 35270,
35273, 35374.
384. Psathyrella limosa A. H. Smith, sp. nov.
Pileus 8-15(-20) mm latus, late conicus vel convexus, glaber, sordide fulvus;
contextu cum "FeSO4" olivaceo-umbrinus; lamellae pallidae demum violaceofuscae, latae, confertae; stipes 1.5-2.5 cm longus, 1-2.5 mm crassus, sparse fibrillosus, pallidus, deorsum demum sordide brunneus; tarde glabrescens; velum
albidum; sporae 7-8x4-4.5,/; pleurocystidia 28-37x9-13 u, late fusoidea vel
fusoide ventricosa, subacuta vel rotundata; fibulae adsunt. Typus. Smith 66751
(MICH); legit prope Burt Lake, Michigan.
Illust. P1. 89, fig. d; Text Figs. 833-835.
Pileus 8-15 (-20) mm broad, obtusely conic to convex, the margin straight at
first, expanding to broadly conic or convex, surface glabrous, moist, hygrophanous
dull tawny when moist, pale dull cinnamon-buff faded, the disc often remaining
a darker tan, faintly striatulate when moist. Context thin, very fragile, odor none,
taste mild, with FeSO4 slightly olive-umber.
Lamellae pallid when young, becoming "benzo brown" from the spores
(violaceous-brown), broad, close, adnate then seceding.
Stipe 1.5-2.5 cm long, 1-2.5 mm thick, equal, fragile, at first with a faint
median white-fibrillose zone left by the breaking of the thin fibrillose veil, becoming dark brown below but base often thinly coated with white mycelium, pallid
and naked above the veil line.
Spores 7-8x4-4.5 A, smooth, apical pore distinct, shape in face view elliptic