The North American species of Psathyrella.

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MEMOIRS OF THE NEW YORK BOTANICAL GARDEN

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versiform: (1) clavate to saccate, 26-38x8-15 p, and walls often yellow as
revived in KOH; (2) fusoid-ventricose as for the pleurocystidia but smaller;
(3) intermediate types with neck showing various degrees of elongation. Caulocystidia 36-62 x 10-18 /A, broadly ventricose, the neck narrow and apex acute,
rarely varying to elliptic in optical section, hyaline, content not distinctive in KOH
or in Melzer's.
Pileus cuticle a layer of broadly clavate vesiculose to pedicellate cells 15-35 p
wide, the walls thin and hyaline, or at base or in the pedicel ochraceous as revived
in KOH; subcuticular region of the trama dark vinaceous-brown as revived in
KOH, the hyphae incrusted with patches of pigment (in age the KOH reaction
paler and yellower on crushed out hyphae). No distinctive reactions on any tissue
when mounted in Melzer's. Clamps present.
Type locality. Tahquamenon Falls State Park, Chippewa County, Michigan.
Habit and habitat. On debris in a wet area.
Distribution. Michigan.
Observations. This variant features large spores, deep coloration of the pileus
(and this is reflected in the KOH reaction of the trama of young basidiocarps),
acute pleurocystidia with narrow neck and very broad mid portion by comparison, in the hyaline nearly naked stipe becoming brown in age, and by the lack
of a veil. It may deserve rank as an autonomous species, but should be carefully
compared with P. pseudogracilis Romagn.
302. Psathyrella superiorensis A. H. Smith, sp. nov.
Pileus 6-14 cm latus, conicus, glaber, demum rugulosa subochraceus, ad marginem demum incarnatae; lamellae confertae demum subdistantes, adnatae, latae,
pallidae demum avellaneae, in exsiccatis atratae; stipes 2-4 cm longus, 1-1.5 mm
crassus, sparse fibrillosus, glabrescens, deorsum brunneus; velum sparsum; spores
11-13 x 5.5-6.5 A: pleurocystidia 50-85 x10-15,x, fusoide ventricosa (collum
elongatum, flexuosum) obtusata; fibulae adsunt. Typus. Ammirati 2251 (MICH);
legit Huron Mountain Club, prope Big Bay, Michigan.
Pileus 6-14 mm, broad, obtusely conic becoming broadly conic, finally somewhat campanulate, glabrous, moist, hygrophanous, becoming rugulose in age,
pallid to grayish on margin at first and disc grayish tawny, when partly faded
developing pinkish tints over marginal area and more or less ochraceous tints over
the disc. Context very thin and fragile, odor and taste not distinctive.
Lamellae close becoming subdistant, adnate, broad, pallid becoming grayish
and as dried blackish, edges pinkish in age.
Stipe 2-4 cm long, 1-1.5 mm thick, delicate, thinly white fibrillose, pallid
above, brownish below, veil if present rudimentary.
Spores 11-13 x 5.5-6.5 p, smooth, apical pore distinct and spore apex truncate,
shape in face view elliptic to ovate, in profile obscurely inequilateral, color in
KOH chocolate-brown becoming dark chocolate-color, in Melzer's bay-brown wall
about 0.6 A thick.
Basidia 4-spored, 10-13 /A broad, clavate. Pleurocystidia scattered, 50-85x
10-15 /j, fusoid-ventricose with long flexuous neck and obtuse apex, some with
a lateral subapical protuberance; wall thin, smooth and hyaline, cell content not
distinctive. Cheilocystidia smaller than pleurocystidia; clavate hyaline to yellowish (in KOH) cells also present.
Pileus cuticle a layer of vesiculose cells 1-2 deep, walls hyaline to yellowish in