The North American species of Psathyrella.

1972]

PSATHYRELLA

57

the cells of the cuticle or from the cuticle cells themselves, with pale rusty cinnamon walls in KOH which are smooth to granular-incrusted (these form the
blackish layer on the pileus). Pileus trama of hyaline inflated smooth-walled
hyphae, clamp connections regularly present.
Type locality. Mt. Rainier National Park, Washington.
Habit and habitat. Cespitose to subcespitose on alder stumps and logs, fall,
rather rare during most seasons.
Distribution. Oregon, Washington.
Observations. This species features minute spores, pleurocystidia shaped like
typical chrysocystidia but lacking the distinctive content, the darkening layer
of veil material of the pileus, and the avellaneous annulus. It is related to
P. lacrymabunda. It is also known from Europe.
Material examined. Oregon: Kauffman 10-7-22; Smith 19532, 20199, 26714,
28319. Washington: Smith 30233, 30240, 31425, 47522, 49019, 49082.
22. Psathyrella duchesnayensis A. H. Smith, sp. nov.
Pileus 3-6 cm latus, convexus, ad marginem griseo-fibrillosus vel squamulosus
et appendiculatus, ad centrum pallide alutaceus et glaber; odor fragrans; lamellae
pallidae demum avellaneae, confertae, angustae, secedentes; stipes 3-6 cm longus,
9-12 mm crassus, deorsum sordide fibrillosus, sursum sericeus, albidus; sporae
6-6.5 x3-3.5 /; pleurocystidia 33-52 x 10-15 u, ad apicerum late rotundata;
caulocystidia sparsa, subclavata vel late fusoide ventricosa; fibulae adsunt. Typus.
Smith 61737 (MICH); legit prope Duchesnay, Quebec, Canada.
Illust. Text Figs. 53-57.
Pileus 3-6 cm broad, convex with an incurved margin, surface moist but not
hygrophanous, appressed-fibrillose near the margin, having dingy grayish buff
fibrils scattered or in patches, the disc glabrous and pale pinkish buff, margin at
first decorated with patches of dingy veil tissue. Context white, firm, taste mild,
odor faintly but distinctly fragrant.
Lamellae whitish at first, becoming vinaceous and finally near vinaceous-drab
(pinkish gray), close, narrow, adnate, soon seceding, edges even.
Stipe 3-6 cm long, 9-12 mm thick, equal, hollow, white within, surface of lower
three fourths coated with dingy buff to grayish veil remnants which terminate in
an evanescent zone of fibrils, apex white and silky.
Spores 6-6.5 x 3-3.5 A, smooth, apical pore present but very minute, shape in
profile allantoid to bean-shaped, in face view nearly oblong, color in KOH pale
fuscous to dark chocolate-color, in Melzer's merely dingy tawny, wall about 0.2 /
thick.
Basidia 4-spored, 21-25 6-7 A, clavate, hyaline in KOH. Pleurocystidia
33-52x 10-15 p, abundant, broadly utriform to broadly fusoid-ventricose with
obtuse to rounded apex; wall thin and smooth, content of cell hyaline in KOH,
not distinctive in Melzer's. Cheilocystidia 35-50 X 8-15 /, narrowly fusoidventricose with obtuse apex to broadly ventricose with short neck and rounded
apex, content not distinctive in KOH or in Melzer's. Caulocystidia present as an
occasional cell near stipe apex and in shape resembling the cheilocystidia.
Pileus with a cuticle of pedicellate and vesiculose cells mixed, 1-3 cells deep,
walls thin and hyaline in KOH, content not distinctive in Melzer's or KOH.
Hyphae of the subcuticular region interwoven, the cells inflated, the walls
perfectly hyaline, in Melzer's the subhymenium in the area adjoining the context