North American species of Mycena.

EUMYCENA: TYPICAE

287

138. MYCENA PELTATA (Fr.) Gillet
Les Hymen., p. 270. 1874
Agaricus peltatus Fries, Epicr. Syst. Myc., p. 110. 1838.
Illustrations: Text fig. 34, nos. 5-6 (p. 289).
Pileus 8-20 mm. broad, convex to obtusely campanulate when
young, usually convex to plane at maturity, occasionally with an
obtuse umbo, sometimes with a shallow depression over the disc,
densely pruinose when young, soon naked, glabrous, surface lubricous
to subviscid from a very thin adnate but somewhat gelatinous pellicle,
nearly opaque or but faintly striatulate when moist, striae more conspicuous as the colors become lighter, disc usually "fuscous" at first,
margin nearly "hair brown," in age evenly "drab gray" (dark gray to
grayish brown, becoming paler and finally cinereous), rather evenly
colored; flesh thin, pliant, grayish or pallid, no odor or taste; lamellae
broadly adnate with a decurrent tooth, close, moderately broad, white
to pale grayish at the base, edges pallid; stipe 3-5 or 8-15 cm. long,
1-2 mm. thick, equal or with a small bulb at the base, tubular, rather
tough and cartilaginous, densely white-fibrillose below, glabrous
above, lubricous (but never viscid) when wet, concolorous with the
pileus or paler.
Spores 8-10 (11) X 3.5-4 u, narrowly ellipsoid or curved slightly
toward the apiculus, amyloid; basidia four-spored; pleurocystidia
not differentiated; cheilocystidia basidium-like but soon developing
contorted fingerlike prolongations, sometimes with wavy outlines,
28-33 X 6-9 A; gill trama homogeneous, vinaceous brown in iodine;
pileus trama with a thin, somewhat gelatinous pellicle, the hyphae of
which have numerous short rodlike projections, hypoderm well differentiated, the cells filled with a dark-brown pigment, the remaining
tissue filamentous, all but the pellicle vinaceous brown in iodine.
Habit, habitat, and distribution.-G-regarious on grassy hummocks
and on sphagnum, late fall; Alabama and Michigan.
Material studied.-Smith, 1148, 1157. Burke, Alabama.
Observations.-Mycena peltata shows the variation in length of
stipe when growing in exposed areas and in deep moss that is characteristic of M. atroalboides. It appears to be very closely related to
M. latifolia both by its gill attachment and by its roughened cheilocystidia. It is more cartilaginous, however, and lacks the conspicuous pleurocystidia.