North American species of Mycena.

EUMYCENA: CORTICOLAE

67

11. MYCENA CORTICOLA (Fr.) S. F. Gray
Nat. Arr. Brit. Plants, 1: 621. 1821
Agaricus corticola Fries, Syst. Myc., 1: 159. 1821.
Prunulus corticalis Murrill, North Am. Flora, 9: 328. 1916.
Agaricus Meliigena Berkeley and Cooke, Grevillea, 6: 129. 1878.
Mycena Meliigena Saccardo, Syll. Fung., 5: 302. 1887.
Prunulus Meliigena Murrill, North Am. Flora, 9: 324. 1916.
Pseudomycena corticola Cejp, Publ. Fac. Sci. Univ. Charles, 104: 142. 1930.
Illustrations:
Plate 5; Text fig. 3, nos. 1-4 (p. 68).
Beardslee and Coker, Journ. Elisha Mitchell Sci. Soc., 40, pl. 10, upper
figs.
Bresadola, Icon. Mycol., 5, pl. 248, fig. 2.
Fries, Icon. Sel. Hymen., I, pl. 85, fig. 2.
Lange, Flora Agar. Dan., 2, pl. 57 E.
Hard, The Mushrooms, Edible and Otherwise, fig. 93.
Pileus 3-10 mm. broad, convex to nearly globose when young,
becoming broadly convex in age, the disc often becoming slightly
depressed, margin straight when young, surface densely and coarsely
pruinose (under a lens) when young, somewhat glabrescent in age
except for the disc and grooves, margin faintly sulcate at first, soon
sulcate or plicate to the center, canescent but soon polished, dark
purplish, soon fading to some shade of vinaceous brown ("army
brown" or "vinaceous brown" and fading to near "wood brown")
and finally pale grayish brown; flesh thin, fragile, concolorous with the
pileus, odor and taste none; lamellae bluntly adnate or slightly decurrent in age, distant, 6-10 reach the stipe, one or two tiers of lamellulae, broad, concolorous with the pileus or a paler and brighter vinaceous brown, edges even; stipe up to 1 cm. 4 long, 0.5 mm. i thick,
equal, fragile, densely pruinose when young and pallid because of the
pruinosity, more or less naked in age and then concolorous with the
gills or pileus, with only a few white hairs at the base, inserted on the
substratum.
Spores globose, 9-11 y, amyloid; basidia four-spored, 30-34 X 8 -10 t, the sterigmata stout; cheilocystidia 26-33 X 8-12 y,, clavate,
the apices echinulate or with contorted fingerlike projections; pleurocystidia none; gill trama purplish red in iodine; pileus trama with a
well-differentiated hypoderm, in tangential section the "cells" 10 -20 j thick, their walls reddish brown, occupying half the thickness