North American species of Mycena.

EUMYCENA: CALODON TES

215

ous, almost inodorous (not with a nitrous odor), taste mild. Gills
19-27 reach the stipe, one to three tiers of lamellulae, sordid whitish
or white with a grayish reflection, with the edge finely bordered fuliginous or grayish black (especially under a lens), ascending, hardly
broad, a bit ventricose, adnate and not uncinate. Stipe 4-5 cm. long,
1.5-3 mm. thick, equal, sometimes prolonged into a root about 13
mm. long, grayish brown or merely laved with gray, paler above,
polished and glabrous, almost shining, fistulose.
Spores ellipsoid to pruniform-ovoid, 7-13 X 5.2-7.2 u; basidia
four-spored (exceptionally three-, five-, six-spored), clavate, 27-35 X
8-10,; gill edge heteromorphic from numerous obtuse fusiform cystidia 40-60 X 11-14,, with their apices sometimes forked, with
grayish-fuliginous or sordid-brownish contents (never yellow or reddish violet); pleurocystidia lacking; subhymenium indistinct; spores,
pileus, flesh, and trama of gills distinctly amyloid.
Habit, habitat, and distribution.-Rare in North America, known
only from one collection in Colorado, on debris on the forest floor.
In Europe it fruits on decaying wood.
Material studied.-Mains, 5908.
Observations.-Mains's collection was made on August 26, 1940,
at Bear Lake in the Rocky Mountain National Park. The spores
measure 8-11 X 5-7 A and the cheilocystidia 36-54 X 9-13 u. The
iodine reactions were as Kuhner described them. The description is
adapted from that of Ktihner. The relationships of the species are
very likely with M. rubromarginata and M. viridimarginata.
100. MYCENA CITRINOMARGINATA Gillet
Les Hymen., p. 266. 1874
Mycenaflavicitrina Murrill, Mycologia, 8: 220. 1916.
Prunulus flavicitrinus Murrill, North Am. Flora, 9: 336. 1916.
Illustrations:
Plate 34; Text figs. 24, nos. 1-2 (p. 216); 25, nos. 7-8 (p. 223).
Bresadola, Icon. Mycol., 5, pl. 222, fig. 2 (as M. elegans).
Lange, Flora Agar. Dan., 2, pl. 50 F (very good).
Pileus (5)10-35 (40) mm. broad, evenly and obtusely conic
when young, the margin appressed against the stipe, soon broadly
conic or obtuse and the margin frequently incurved, at maturity
conic-campanulate, obtusely umbonate, or broadly convex, the margin
frequently flaring, surface moist, pruinose but soon naked and pol