The North American species of Psathyrella.

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MEMOIRS OF THE NEW YORK BOTANICAL GARDEN

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dark cocoa-color slowly chocolate-brown, in Melzer's dull red, wall about 0.3 Kt
thick.
Basidia 22-28x8-10 j, clavate, hyaline in KOH, 4-spored. Pleurocystidia
abundant, 48-60 X 10-20 A, fusoid-ventricose with elongate neck and obtuse to
subcapitate apex (rarely forked at apex), hyaline in KOH or rarely ochraceous.
Cheilocystidia similar to pleurocystidia but more often rusty brownish as revived
in KOH. Caulocystidia clavate to fusoid-ventricose with obtuse to rounded apex,
hyaline in KOH, scattered.
Gill trama interwoven, hyaline to yellowish in KOH (ochraceous in young pilei
as revived in KOH but fading). Pileus trama with subcuticular rusty brown
hyphae, color paler toward the subhymenium. Cuticle of pileus a palisade of
clavate to inflated cells which become somewhat disarranged in age, the walls at
the base of the cell often rusty brown to yellowish in KOH. Clamp connections
present.
Type locality. Mud Lake Bog, Cheboygan County, Michigan.
Habit and habitat. Scattered on rotten wood of aspen (?) and on debris.
Distribution. Michigan.
Observations. The distinguishing features of the species are the appendiculate
margin of the pileus when the veil breaks, the relatively broad spores for their
length (in face view), the obtuse to subcapitate pleurocystidia, the cheilocystidia
mostly with broadly rounded apex, and the tendency for the stipe to become
brownish below.
Material examined. Michigan: Potter 8294, 8782, 8786, 8787, 8796, 8884,
9122; Smith 25205, 25206, 32141, 32322, 33710, 33728, 33756, 33770, 33773, 33777,
33781, 33784, 33789, 33794, 33799, 33801, 33815, 33909, 33930, 34091 (Type).
83. Psathyrella velibrunnescens A. H. Smith, sp. nov.
Pileus (2-)3-6(-7.5) cm latus obtuse conicus demum late campanulatus vel
plano-umbonatus, glaber, appendiculatus, fusco-fulvus vel cinnamomeo-brunneus,
demum rugoso-reticulatus; lamellae confertae, adnatae, latae, "vinaceous buff"
demum sordide cinnamomeae; stipes 5-8(-10) cm longus, (3-)4-7(-10) mm crassus, fibrillosus pallidus demum brunneus; sporae 7-9x4-5 /; pleurocystidia
38-58x 10-14 A, ad apicerum obtuse vel late rotundata; fibulae adsunt; velum
pallidum demum sordide brunneum. Typus. Smith 13240 (MICH); legit prope
Kalaloch, Washington.
Illust. P1. 27, fig. b; P1. 44, fig. a; Text Figs. 210-212.
Pileus (2-) 3-6 (-7.5) cm broad, obtusely conic, becoming more or less expanded
or broadly campanulate, often with a broad flattened umbo, glabrous except for
marginal fibrillose to submembranous patches of pallid to pale avellaneous veil
remnants which in age usually discolor to dingy cinnamon-buff, surface when
moist "russet" to "Mars brown" (dark rusty brown), hygrophanous and fading
to pallid ("tilleul buff" or a dingy "cinnamon-buff"), surface frequently rugulosereticulate around the disc and radially rugulose toward the margin, often fading
first along the ridges. Context thin, fragile, concolorous with the surface; odor and
taste mild.
Lamellae close (30-40 reach the stipe), bluntly adnate, but soon seceding,
broad, (4-7 mm), equal or tapering toward the margin of the pileus, "vinaceousbuff" when young, "Verona brown" at maturity, edges whitish and crenulate.
Stipe 5-8 (-10) cm long, (3-)4-7 (-10) mm thick, equal, hollow, fragile, surface