North American species of Mycena.

EUMYCENA: CALODONTES

219

fungus of this type. If the fungus Bisby collected is found to have
slightly colored gill edges, it should be considered a variety of M.
citrinomarginata; otherwise, it should be placed in the Adonidae.
This point needs clarification.
101. MYCENA OLIVACEOBRUNNEA A. H. Smith
Mycologia, 29: 339. 1937
Illustrations;
Plate 49 D; Text fig. 25, nos. 5-6 (p. 223).
Smith, Mycologia, 29: 353, fig. 3 C.
Pileus 5-10 mm. broad, obtusely conic, becoming obtusely campanulate but seldom expanding, margin appressed against the stipe
when young, surface glabrous, moist, striate to disc with broad dark
lines, color when moist "buffy brown" to "dark olive buff" with a
pallid margin, fading to sordid yellowish gray; flesh very thin and
membranous, pallid, odor and taste not distinctive; lamellae ascending-adnate, close to subdistant, 14-16 reach the stipe, narrow to
moderately broad at maturity (1-1.5 mm. ~), sordid yellowish gray,
edges bright lemon yellow; stipe 2-6 cm. long, (0.5) 1-1.5 mm. thick,
equal, tubular, rather weak and very fragile, glabrous and polished
above, base sparsely white-strigose, color "olive brown" toward the
base, "deep olive buff" or sordid yellowish gray above.
Spores 6.5-8 X 4-4.5 /, (8-10 X 4-5,, two-spored), ellipsoid,
amyloid; basidia two- or four-spored; pleurocystidia not differentiated; cheilocystidia 30-44 X 8-18 A, fusoid-ventricose to clavate,
with or without a narrowed neck, the neck sometimes branched or
occasionally with scattered blunt projections over the enlarged portion; pileus trama with a thin pellicle, a well-differentiated hypoderm,
and a narrow region of filamentous tissue; both the gill and pileus
trama sordid vinaceous brown in iodine.
Habit, habitat, and distribution.-Densely gregarious on humus,
moss carpets, and needle beds under second-growth Douglas fir during
May, June, September, and October; Washington to California.
Often scattered in deep moss and very inconspicuous.
Material studied.-Smith, 2507, 3279, 8277, 13992, 14066, 16710.
Observations.-This fungus is distinguished from M. citrinomarginata by its consistently smaller size and smaller spores. From
M. flavifolia it differs by having a colored gill edge and smoother
cystidia. M. olivaceomarginata Massee appears to be close but is