The North American species of Psathyrella.

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MEMOIRS OF THE NEW YORK BOTANICAL GARDEN

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Cheilocystidia fusoid-ventricose and shorter than the pleurocystidia and many
merely obtuse at apex. Caulocystidia 30-75 x10-20 p, utriform to broadly inflated both near the base and apex, broadly rounded, hyaline, smooth, scattered.
Gill trama regular, of large inflated cells rather irregularly arranged, pale
brown to rusty brown as revived in KOH. Pileus trama floccose, interwoven, pale
rusty brown in KOH, walls smooth to obscurely roughened. Cuticle of pileus of
vesiculose hyaline cells one cell deep or irregularly 2 cells deep. Clamps present.
Type locality. Great Smoky Mountains National Park, Tennessee.
Habit and habitat. Clustered on a laurel stub.
Distribution. Alabama, Tennessee.
Observations. The caulocystidia appear to be an additional distinguishing
feature of this species not given in the original description.
Material examined. Alabama: Burke 8-9-42; Tennessee: Smith 10793 (Type).
344. Psathyrella parvifibrillosa A. H. Smith, sp. nov.
Pileus 1-3(-4) cm latus, late conicus, sparse fibrillosus demum glaber, cinnamomeo-brunneae vel fulvus; lamellae latae confertae, brunneolae demum
griseo-brunneus; stipes sursum pallidus deorsum sordide brunneus; sporae 7-9 X
4.3-4.8 (8-11 x 4.5-5) u; pleurocystidia 40-62 (-75) x 9-18 u, fusoideo-ventricosa,
elongata, obtusa; fibulae adsunt. Typus. Smith 39069 (MICH); legit prope
Tahquamenon Falls, Luce County, Michigan.
Illust. P1. 95, fig. a; Text Figs. 746-750.
Pileus 1-3(-4) cm broad, obtusely conic and expanding to broadly conic, at
first covered by a thin layer of pallid fibrils, margin appendiculate with fibrils,
soon glabrescent, color "cinnamon-brown" on the disc and "ochraceous-tawny"
on the margin which when moist is striatulate, fading to near cinnamon-buff.
Context very thin and fragile, odor and taste mild.
Lamellae ascending-adnate, broad, close, pallid brownish becoming graybrown as spores mature, edges whitish.
Stipe 2-5 cm long, 1.5-2.5 mm thick at apex, equal or nearly so, hollow,
fragile, whitish above, dingy brownish below, apex pruinose-scabrous, lower down
appressed-fibrillose, glabrescent.
Spores 7-9 x 4.3-4.8 (8-11 x 4.5-5) A, smooth, apical pore not readily evident
and the apex rounded, in face view ovate to elliptic (or in large spores narrowly
wedge-shaped), in profile obscurely inequilateral (or in long spores almost
boletoid), color in KOH cocoa-color and darkening very slowly, in Melzer's
reddish tawny, reddish in water mounts when fresh, wall about 0.3 / thick.
Basidia 4-spored, 17-22x 7-9 A, hyaline in KOH. Pleurocystidia 40-62(-75)
x 9-18 u, elongate fusoid-ventricose with obtuse apex, broadly and obtusely
fusoid or (rarely) utriform, often with granular incrustation (revived in KOH)
over apical region, wall thin and hyaline, cell content not distinctive in either
KOH or Melzer's. Cheilocystidia vesiculose to saccate-clavate and 24-35 x 9-15 Iu,
others obtusely fusoid to fusoid-ventricose and 26-38 x 10-14 t, thin-walled,
hyaline, apex of some having granular incrustations. Caulocystidia a mixture
of vesiculose to clavate to utriform and fusoid-ventricose types of various sizes,
some clavate to obovate-pedicellate cells up to 60 x25 u present, walls thin and
smooth.
Cuticle of pileus a layer of vesiculose cells yellowish in sections revived in
KOH, in sections their walls thin and smooth, content not distinctive. Subcuticular
region of hyphae with rusty cinnamon walls in KOH and with incrusting pigment