North American species of Mycena.

90 NORTH AMERICAN SPECIES OF MYCENA

spored), clavate, 16-18 X 4.2-5.5 j,; pleurocystidia and cheilocystidia
lacking; gill trama interwoven in radial sections; pileus covering of
appressed short hyphae (not filiform), 5-10, in diameter, irregularly
echinulate with short rodlike projections but very dense and with
numerous upright hairs 37-57, long, which are somewhat inflated at
the base (4-7gu), gradually attenuated (or contracted) to a slender
filament 1-2. thick, obtuse, with thin walls, and at the base often
curved or with irregular spurs; flesh of pileus continuous with that of
the stipe; covering of the stipe of hyphae bearing rodlike projections
but not densely echinulate, and having numerous thin-walled projecting hairs similar to those of the pileus (28-45 X 4-6.5,).,:
22. MYCENA GRACILIS (Quel.) Kiihner
Encyc. Myc., 10: 650. 1938
Omphalia gracilis Quelet, Champ. Jura et Vosges, Suppl. 10: 662. 1880.
Agaricus (Mycena) immaculata Peck, Ann. Rep. New York State Mus., 38:
84. 1885.
Mycena immaculata Saccardo, Syll. Fung., 5: 264. 1887.
Omphalopsis immaculata Murrill, North Am. Flora, 9: 312. 1916;
Illustrations:
Plate 8 B, D; Text fig. 7, no. 1.
Bresadola, Icon. Mycol., 6, pl. 270, fig. 1 (as Omphalia).
Konrad et Maublanc, Icon. Sel. Fung., pl. 236, II.
Pileus 3-14 mm. broad, conic with an appressed margin at first,
becoming campanulate to convex, seldom plane, often papillate,
surface glabrous, moist, translucent-striate before losing moisture,
snow white over all or occasionally developing a sordid-yellowish cast
over the disc; flesh very thin and fragile, odor and taste not distinctive;
lamellae adnate to hooked, soon developing a distinct decurrent tooth,
subdistant (10-15 reach the stipe, two or three tiers of lamellulae),
moderately broad (often nearly triangular in outline), sometimes seceding, pure white, edges even and white; stipe (1) 3-6 (7) cm. long,
0.5-1 mm. thick, equal, fragile, strict or flexuous, tubular, fragile,
pure white, base attached to needles by distinct white hairs (sometimes densely strigose, at other times nearly glabrous), translucent
and glabrous above, finely pruinose-especially toward the apex when
viewed under a lens-pure white, usually watery white when perfectly fresh.
Spores 7-9 X 2.5-3,, nearly cylindric, smooth, nonamyloid;
basidia either two- or four-spored; pleurocystidia not differentiated;