North American species of Mycena.

EUMYCENA: TYPICAE

panulate, sometimes convex with a flaring margin, hoary owing to a
pruinose coating, slowly becoming naked and moist, glabrous, translucent-striate, becoming sulcate, the surface becoming uneven at
times, fuscous to blackish at first (after removal of pruinose coating),,
soon fading from dark to light gray and finally cinereous; flesh thin
and fragile, grayish, taste acidulous, odor weakly alkaline (rather
strong if flesh is crushed); lamellae narrow, equal, ascending-adnate
and toothed, subdistant, 18-27 reach the stipe, one or two tiers of
lamellulae, pallid or cinereous, edges pallid and even; stipe (2) 4-6
(12) cm. long, 1-2 mm. thick, equal, hollow, very fragile, usually
bluish black at first (darker than the pileus) but soon sordid brownish
gray, finally fading to pallid or cinereous, densely white-pruinose over
all but soon polished and translucent, base nearly glabrous to rather
densely white-strigose.
Spores 7-10 X 4-6 u, broadly ellipsoid, amyloid; basidia usually
four-spored (two- and three-spored forms have been found on which
the spores measured 11-12 X 6-6.5 it or 8-10 X 3.5-4.5 /t); pleurocystidia scattered, rare or absent, 30-44 X 9-13 A, variable in shape,
fusoid-ventricose to clavate, the apex forked in some, the clavate
individuals occasionally bearing two or three fingerlike prolongations;
cheilocystidia numerous, similar to pleurocystidia; gill trama homogeneous, composed of enlarged hyphae, vinaceous brown in iodine;
pileus trama with a well-differentiated pellicle, the cells of which bear
numerous rodlike prolongations, hypoderm well formed, the remaining
tissue floccose, all but the pellicle vinaceous brown in iodine.
Habit, habitat, and distribution.-Scattered to gregarious on fallen
sticks and on needle carpets under conifers, rather common during
early summer and again in the fall; Nova Scotia, Manitoba, to Washington and south to California and North Carolina.
Material studied.-Smith, 32-383, 32-466, 32-519, 32-598, 32 -603, 32-604, 32-605, 32-654, 33-879, 780, 876, 3079, 3515, 5092, 6189,
7774, 8037, 8045, 8052, 8498, 8751, 9077, 14112, 14260, 14564, 14957,
15039, 16208, 16418, 16511, 16583, October 31 and November 21,
1931. Drayton, Ottawa, Canada. Flett, Washington, February 10,
1940. Kauffman, Maryland, New York, Michigan, Washington,
Oregon (as M. ammoniaca). Mains, 34-75, 5078. Parlin, 15329,
Maine. Slipp, UIFP: 2598, Idaho. Stuntz F 418, 420 Wehmeyer, 876.
Observations.-In most respects M. leptocephala is just another