North American species of Mycena.

186 NORTH AMERICAN SPECIES OF MYCENA

85. MYCENA SUBAQUOSA A. H. Smith
Mycologia, 31: 278. 1939
Illustration: Plate 22.
Pileus 2-3.5 cm. broad, obtuse to convex, becoming broadly convex
to nearly plane, margin appressed against the stipe when young but
soon becoming connivent with it and somewhat recurved in age, translucent-striate to the disc when moist, glabrous, hygrophanous, watery
and dull white except for the milky-white disc, at maturity the disc
becoming tinged with watery gray, fading and becoming shining whitish; flesh thickish, watery white, very soft and fragile, odor and taste
very pronounced, resembling those of radish or more pungent; lamellae
adnate but soon becoming adnexed, close, 26-32 reach the stipe, in
three to four tiers, broad and ventricose (3-4 mm.), concolorous with
the pileus, edges even and whitish; stipe 4-9 cm. long, 2-3 mm. thick,
hollow, equal, very fragile, glabrous except for sparse white hairs at
the base, apex naked or faintly frosted, white and translucent over all.
Spores narrowly ellipsoid, 5-6.5 (7) X 2.5-3 g, amyloid; basidia
four-spored, 20-23 X 5-6 t; cheilocystidia abundant, broadly fusoid
with obtuse apices or the necks somewhat elongated, smooth, hyaline,
30-45 X 9-18 /p; pleurocystidia scattered to numerous, fusoid-ventricose with rounded apices, hyaline, 40-60 X 10-16 tui; gill trama
vinaceous brown in iodine; pileus trama with a scarcely differentiated
pellicle, below this a region of compact radially arranged hyphae, the
remainder of floccose filamentous tissue, in iodine vinaceous brown
except for the pellicle.
Habit, habitat, and distribution.-Gregarious under western red
cedar on moss and debris during October; Washington and Oregon.
Material studied. -Smith, 7813, 17146, 17251.
Observations.-This species is similar to M. pura in its spores,
cystidia, and radishlike odor. Although M. pura was found everywhere in the conifer forests around McKenzie Pass during the 1937
season, it was consistently different from the specimens described
above. According to my experience, in the white form of M. pura
the odor is not exceptionally strong, the colors are usually faintly
pinkish or lilac on the disc of the cap and at the apex of the stipe,
and the stature and consistency are the same as for the other color
forms of the species. In stature M. subaquosa is more like M. polygramma. This difference cannot be considered a variation caused
by the habitat because typical specimens of M. pura were collected