The North American species of Psathyrella.

1972]

PSATHYRELLA

65

to give the marginal area a coarsely striate appearance, near cinnamon-buff faded.
Context firm but fragile, near snuff brown when moist, fading to near avellaneous,
taste mild, odor sweetish-aromatic.
Lamellae close to crowded, broad, ascending adnate, avellaneous becoming
gray-brown ("wood brown") at maturity, dingy vinaceous-brown when dried,
edges even to slightly crenulate.
Stipe 8-10 cm long, 7-8 mm thick at apex, equal to evenly enlarged downward,
hollow, not exceptionally fragile, the cavity lined with avellaneous tissue, the
cortex whitish, surface white and densely fibrillose-squarrose scaly below the
cottony-membranous fringed annulus, scales white but tips fuscescent, pruinose
and silky-striate above the superior annulus.
Spores 9-12x4.5-6 u, smooth, apical pore not evident under low-power oilimmersion, shape in face view broadly ovate to subelliptic, in profile obscurely
inequilateral (suprahilar area flattened), with a prominent apiculus, color in
KOH distinctly cocoa-color but slowly darkening to a grayish chocolate-brown
on standing, reddish tawny in Melzer's, wall about 0.4 ) thick.
Basidia 4-spored, 24-30 x9-10 1, clavate, hyaline in KOH. Pleurocystidia
scattered, 36-54x (12-)14-22 x, broadly ventricose with a short neck ending
in an obtuse to rounded apex, wall thin, smooth and hyaline, content not distinctive in KOH or Melzer's or rarely in KOH with numerous minute droplets.
Cheilocystidia similar to pleurocystidia and some narrower and more elongated
(50-65 x 9-13,), the neck often drawn out and flexuous in outline, walls thin
and hyaline, content of some oily in KOH. Caulocystidia elongate-clavate
(9-18 f wide) or flexuous-filamentous (8-10 u wide) or resembling the pleurocystidia, rarely with a pale cinnamon-colored dissolved content as revived in
KOH, walls thin and hyaline. Cortex hyphae rather refractive in KOH but
smooth.
Pileus with a cuticle formed by a layer of vesiculose cells 3-5 deep, the
walls hyaline, thin and smooth, content not distinctive in KOH or Melzer's.
Hyphae of the trama flushed with cinnamon when first revived in KOH but
soon fading. Not distinctive in any part when mounted in Melzer's. Clamp
connections present, typically prominent.
Type locality. Europe.
Habit and habitat. Cespitose on or near conifer wood such as stumps etc.
Distribution. Washington (Smith 30907).
Observations. There is remarkable agreement in the literature as to the
features of this species though it apparently is generally rare. The stipe is much
more cottony below the annulus than in P. pseudocotonea. For additional
comment see that species. The rather distinct apiculus of the spores is an
important feature.
29. Psathyrella annulata A. H. Smith, sp. nov.
Pileus 3-5 cm latus demum subplanus, minute squamulosus, glabrescens,
melleibrunneus; lamellae confertae, latae, secedentes, pallide cinnamomeae demum
cacaocolor; stipes 9-13 cm longus, 5-9 mm crassus, pallidus, deorsum sericeus,
sursum annulatus; annulus membranaceus, tenuis, sursum striatus, deorsum
squamulosus; sporae 11-14(-15) x6-7.5 f; pleurocystidia 46-77x13-20 /, ad
apicerum late rotundata vel subacuta; fibulae adsunt (sparsae). Typus. Smith
76887 (MICH); legit prope Priest Lake, Idaho.