North American species of Mycena.

72 NORTH AMERICAN SPECIES OF MYCENA

14. MYCENA CORTICALIS A. H. Smith
Mycologia, 31: 268. 1939
Illustrations:
Plate 7 D; Text fig. 3, nos. 5-6 (p. 68).
Smith, Mycologia, 31, fig. 1-B (spores).
Pileus 6-12 (15) mm. broad, cylindric, conic or convex, remaining
unexpanded, the disc often becoming slightly flattened, margin
appressed against the stipe when young, glabrous, hygrophanous,
translucent-striate when moist, pale to dark watery gray on the disc
and the margin whitish, fading to cinereous and becoming sulcate;
flesh thin, fragile, grayish, odor and taste mild; lamellae arcuate or
broadly adnate with a distinct decurrent tooth, rather distant, 11-13
reach the stipe, broad (3 mm. i), whitish to pale gray; stipe 1-2.5 cm.
long, about 1 mm. thick, equal, straight or curved, tough and cartilaginous, glabrous, moist, concolorous with the pileus or paler
toward the apex, slightly strigose at the base.
Spores broadly ovoid and pointed at one end, 9-11 X 7-9 A, nonamyloid; basidia four-spored, 34-46 X 8-10 t; cheilocystidia embedded and very inconspicuous, 20-25 X 6-8,, with simple or
branched projections (5-15 X 1.5-2,) scattered over the surface of
the upper (enlarged) portion; pleurocystidia not present; gill trama
vinaceous brown to wine red in iodine; pileus trama covered with a
very thin adnate pellicle made up of very slender hyphae, below it a
region of somewhat inflated irregularly shaped cells rather compactly
arranged, the remainder of loosely arranged hyphae with rather wide
cells, all of the tissue below the pellicle becoming wine red to vinaceous
brown in iodine.
Habit, habitat, and distribution.-Scattered on cedar bark (Thuja
plicata) during October and November; Oregon. It has been found
only on logs and trees that lacked a covering of Bryophytes. It is
apparently quite rare.
Material studied.-Smith, 8046, 8159, 8918.
Observations.-The spores were originally described as hyaline to
pale bluish in iodine, hence amyloid. These observations were made
on freshly dried material. The type has been rechecked, and the
spores have been found to be very pale yellow or hyaline, and consequently are only very weakly or not at all amyloid. The pileus and
gill trama gave the typical reddish reaction previously observed.
Both mature and immature fruiting bodies were studied. The most