The North American species of Psathyrella.

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MEMOIRS OF THE NEW YORK BOTANICAL GARDEN

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chusetts: Smith 67297. Michigan: Smith 15032. Tennessee: Hesler 18895
(Type).
89. Psathyrella brunnescens A. H. Smith, sp. nov.
Pileus 3-5 cm latus, obtuse conicus demum plano-umbonatus, glaber, ad
marginem leviter appendiculatus, glabrescens, cinnamomeo-brunneus; velum
avellaneum, submembranaceum; lamellae confertae, angustae, adnatae, avellaneae demum sordide vinaceo-brunneae; stipes 4-7 cm longus, 4-8 mm crassus,
sparse fibrillosus, deorsum demum spadiceus; sporae 7-8 x 4.5-5 U; pleurocystidia
36-50 x9-15 i fusoide ventricosa, obtusa vel rotundata; fibulae adsunt. Typus.
Smith 39049 (MICH); legit prope Tahquamenon Falls State Park, Luce County,
Michigan.
Illust. Text Figs. 222-224.
Pileus 3-5 cm broad, obtusely conic, expanding to broadly conic or planoumbonate, glabrous, or at first with thin patches of fibrils near the margin, margin
dentate-appendiculate from remains of an avellaneous submembranous partial
veil, soon denuded of veil remnants both on edge and over surface, color dull rusty
brown ("Mars brown" to "cinnamon-brown"), hygrophanous and fading to dingy
pale tan and then often rugulose, fading in spots causing the pileus to appear
mottled. Context thin, fragile, colored like the surface, lacking an odor or taste.
Lamellae close, narrow (broadest near the stipe), bluntly adnate, avellaneous
to wood brown or more vinaceous, with a rusty cinnamon tone as dried, edges even.
Stipe 4-7 cm long, 4-8 mm thick, equal or nearly so, fragile, tubular, surface
thinly pallid-fibrillose, darkening to dull brown (date brown) below, apex white
pruinose-scabrous, also long-striate and fibrillose.
Spores 7-8x4.5-5 I, smooth, apical pore distinct, shape in face view elliptic
to ovate, in profile obscurely inequilateral, color in KOH fuscous (with a weak
ochraceous tint), in Melzer's tawny to slightly redder, wall about 0.2 I thick.
Basidia 4-spored, 18-23 x6-8 p, clavate, hyaline. Pleurocystidia 36-50 x
9-15 I,, utriform to fusoid-ventricose with obtuse apex, thin-walled, smooth,
content not distinctive. Cheilocystidia clavate to broadly fusoid-ventricose,
smooth, thin-walled, hyaline. Caulocystidia scattered in small patches, clavate
to ventricose, walls mostly yellowish in KOH but thin.
Pileus with a cuticle of a layer of vesiculose cells about 1 cell deep, hyaline
in KOH, reviving poorly; trama (including subcutis) bright rusty brown in KOH
and hyphae having local wall thickenings dark tawny in KOH and causing a
spotty appearance on revived sections, in Melzer's the thickenings not as highly
colored. Clamps present. No distinctive reaction when mounted in Melzer's.
Type locality. Tahquamenon Falls State Park, Luce County, Michigan.
Habit and habitat. Scattered on hardwood logs, July.
Distribution. Michigan.
Observations. This species features rusty brown pileus and lamellar trama as
revived in KOH, the stipe becomes dark date brown over the basal area when
fresh, the pleurocystidia are mostly rounded at the apex but some obtuse to
subacute cells can be found, and the spores are rather short and broad.
Material examined. Michigan: Smith 39049 (Type), 41591.
90. Psathyrella septentrionalis A. H. Smith, sp. nov.
Pileus (1.5-) 2-5 cm latus, obtusus vel convexus demum late convexus,
cinnamomeo-brunneus, ad marginem denticulato-appendiculatus glabrescens;