North American species of Mycena.

EUMYCENA: TYPICAE

281

pears to be most closely related to M. plicosa. It is distinguished
from M. plicosa by its less fragile stipe, a tendency to develop yellow
tints along the margin of the pileus, the thinner pellicle, and the less
pronounced amyloid reaction of the trama of the gills and pileus.
135. MYCENA ATROALBOIDES (Pk.) Saccardo
Syll. Fung., 5: 276. 1887
Agaricus atroalboides Peck, Ann. Rep. New 'York State Mus., 27: 93. 1875.
Prunulus atroalboides Murrill, North Am. Flora, 9: 329. 1916.
Illustrations:
Plates 47 A, 53 C; Text fig. 32, nos. 9-10 (p. 268).
Lange, Flora Agar. Dan., 2, pl. 54 I (short-stiped form).
Smith, Am. Journ. Bot., 22, pl. 2, fig. 2.
Pileus 1-2 cm. broad, ovoid to convex or obtusely conic when
young, becoming broadly conic or with a distinctly flattened disc,
expanding and finally plane or with a low flattened umbo, margin connivent or curved in slightly when very young, flaring or recurved in
age and frequently wavy or crenate, surface moist, at first conspicuously hoary, the bloom often persisting until late maturity,
smooth or somewhat rugulose, translucent-striate toward the margin
when moist, subhygrophanous and fading slowly, color "Chaetura
black," "bone brown," or "fuscous" when young, the margin at first
"cinnamon drab" to "drab," at maturity paler but retaining the faint
cinnamon tinge, fading slowly to "pale smoke gray" over all, sometimes spotted reddish brown-particularly in wet weather; flesh thin
but cartilaginous, concolorous with the surface (blackish to pallid),
and occasionally stained reddish brown, taste and odor mild or very
slightly of radish; lamellae ascending-adnate and with a distinct
decurrent tooth, becoming horizontal and shallowly adnexed, close
to subdistant, 19-25 reach the stipe, three tiers of lamellulae, narrow
to subventricose in age (1.5-3 mm.), at times strongly intervenose,
pallid grayish to dark gray, sometimes white when young, sometimes
staining reddish brown in age or entirely rubescent, often strongly
intervenose, edges pallid and even; stipe 2-4 cm. (when growing on
needle carpets) or 5-12 cm. long (when growing in sphagnum), 1-2
mm. thick, equal, often flexuous, tubular, cartilaginous-brittle, with
a whitish bloom at first, soon naked and polished, base densely whitestrigose, concolorous with the pileus but soon paler, especially above,
often with an abundant clear watery juice.