North American species of Mycena.

EUMYCENA: TYPICAE

319

Pileus 1.5-3 cm. latus, obtuse conicus demum campanulatus vel
umbonatus, glaber, striatus, hygrophanus, sordide albidus demum
pallide vinaceus, margine albidus, expallens subcandidus, crenatus;
lamellae confertae, angustae demum latae, adnatae, candidae dein
pallide incarnatae; stipes 3-5 cm. longus, 2-3 mm. crassus, cavus,
deorsum albostrigosus, sursum pruinosus, subcandidus; sporae 8-10
X 5-6 u; basidia tetraspora; cheilocystidia 40-60 X 9-12 (15),
fusoide ventricosa. Specimen typicum in Herb. Univ. Mich. conservatum. Legit A. H. Smith, n. 15267, prope Ann Arbor, Mich.,
Sept. 9, 1940.
Pileus 1.5-3 cm. broad, obtusely conic, becoming campanulate
or broadly expanded with an obtuse umbo, surface moist, faintly
pruinose when young, glabrous, translucent-striate, hygrophanous,
whitish at first, soon pale grayish vinaceous over the disc and with
a white margin ("tilleul buff" in buttons but soon "pale vinaceous
fawn" or tinged brighter pink over the disc), nearly snow white when
faded and then opaque, occasionally with rusty stains in age, the
margin appressed against the stipe by a rather broad sterile band,
the sterile portion becoming crenate in age (as in M. haematopus),
flesh thin but firm, watery white, becoming snow white, with a scant
hyaline watery juice, odor and taste mild, lamellae ascending-adnate,
narrow to moderately broad (2.5-3.5 mm.), broadest near the stipe
and tapered evenly to the margin, close, 22-27 reach the stipe, one
or two tiers of lamellulae, pure white at first but soon flushed evenly
with clear pale pink, edges minutely fimbriate but even and whitish,
not spotted; stipe 3-5 cm. long, 2-3 mm. thick, terete or compressed,
hollow, with a scanty clear watery juice, rather firm but brittle, base
white-strigose, upper portion hoary-pruinose, hyaline white over all,
becoming opaque and somewhat glabrescent, occasionally with
scattered rusty stains but base remaining white in age.
Spores 8-10 X 5-6 A, ellipsoid, smooth, amyloid; basidia fourspored; pleurocystidia not differentiated; cheilocystidia abundant,
hyaline or with a granular-appearing highly refractive content, 40 -60 X 9-12 (15),, fusoid-ventricose with pointed evenly tapered
apices or the apices forked or sparsely branched; gill trama homogeneous, not colored in iodine; pileus trama not amyloid, with a thin
pellicle, the cells of which give off scattered short branches, hypoderm
hardly differentiated from the tramal body.
Habit, habitat, and distribution.-Cespitose on a black-cherry