North American species of Mycena.

204 NORTH AMERICAN SPECIES OF MYCENA

among oak leaves; Michigan. To date it has appeared during October and November, and has been found abundantly in only one
locality.
Material studied. -Smith, 32-430, 32-474, 32-491, 32-578, 33 -1048, 5038, October 7, 1931, Michigan.
Observations.-Previously (1936) I regarded this species as merely
a form of M. elegans. Its cystidia, however, constantly average
larger than those of M. elegans and have, in addition, a rather distinctive shape. Failure to find the fungus in quantity in more than
one locality precludes drawing conclusions about the effect of locality
on the habit. As I have observed the fungus to date, the lack of
reddish stains on the gills and stipe, the subcespitose manner of
growth, flexuous stipe, and more or less rooting base, along with the
very pale-yellow gill edges, characterize it macroscopically. Fruiting
bodies, particularly old pilei, have been found in which there was no
yellow on the gill edges. Sometimes, however, the yellow colors
become more pronounced as the specimens age. During the season
of 1939 a group of old carpophores was found which were similar in
color to old specimens of M. citrinomarginata. The echinulate
cystidia of M. flavescens readily distinguish such forms.
94. MYCENA ROSELLA (Fr.) Quelet
Champ. Jura et Vosges, p. 241. 1872
Agaricus rosellus Fries, Syst. Myc., 1: 151. 1821.
Omphalia rosella S. F. Gray, Nat. Arr. Brit. Plants, p. 615. 1821.
Prunulus roseolus Murrill, North Am. Flora, 9: 324. 1916.
Illustrations:
Plate 26 C, 30; Text fig. 20, nos. 3-5 (p. 194).
Konrad et Maublanc, Icon. Sel. Fung., 3, pl. 224 I.
Lange, Flora Agar. Dan., 2, pl. 54 F, F' (good).
Ricken, Die Blatterpilze, 2, pl. 109, fig. 5.
Pileus (5) 10-20 (30) mm. broad, obtusely conic with a slightly
incurved margin at first, occasionally sharply conic, becoming campanulate to convex and in age often becoming plane, occasionally with
a small conic umbo (almost a papilla), surface moist to lubricous,
translucent-striate, "light russet vinaceous" to "flesh pink" at first,
becoming paler and- developing ochraceous tints in age (bright pink
tinged with gray on the disc, the margin a clearer pink at first or
evenly colored over all, fading and becoming more yellowish in age);