North American species of Mycena.

352 NORTH AMERICAN SPECIES OF MYCENA

171. MYCENA RUGULOSICEPS (Kauff.) Smith
Mycologia, 29: 342. 1937
Collybia rugulosiceps Kauffman, Pap. Mich. Acad. Sci., Arts, and Letters,
5:126. 1926.
Illustrations:
Plate 84; Text fig. 43, nos. 2, 4 (p. 349).
Kauffman, Pap. Mich. Acad. Sci., Arts, and Letters, 5, pl. 6.
Pileus (2.5) 3.5-6 (7) cm. broad, obtuse when young, becoming
broadly campanulate to convex or more or less plane, the umbo often
disappearing, the margin frequently more or less incurved and in age
often becoming elevated, surface covered with a hoary bloom at first,
soon becoming shining and polished, lubricous when wet, margin
opaque but becoming faintly translucent-striate when nearly mature,
becoming radially wrinkled to rugulose or sulcate, color "blackish
mouse gray" when young, becoming "drab" on the disc and watery
gray along the margin, sometimes entirely "pale smoke gray," subhygrophanous, fading slowly to "avellaneous" with a sordid-brownish
darker disc; flesh thick on the disc, tapering gradually and thin over
the marginal area, whitish to cinereous, very tough and cartilaginous,
odor and taste not distinctive; lamellae adnate to somewhat adnexed,
at times sinuate in age, usually with a decurrent tooth, close but
becoming subdistant, 28-36 reach the stipe, broad (5-7 mm.), nearly
equal or tapered at the margin, in age sometimes subventricose,
strongly intervenose, rigid and firm, white or pale grayish, becoming
sordid gray or flushed with pinkish and appearing grayish pink, sometimes stained sordid reddish brown in spots, edges even; stipe variable
in length, depending on the habitat, 5-8 cm. long in open places and
8-12 cm. long when growing from buried wood or on the debris on the
forest floor in wet places, 4-8 mm. thick, sometimes with a short
pseudorhiza, hollow, very tough and cartilaginous, glabrous, smooth
or more or less twisted-striate, blackish to pale or dark sordid gray or
grayish brown below, whitish or merely pallid above.
Spores ellipsoid, 8-10 X 5-6 (7),, amyloid; basidia four-spored,
38-40 X 8-9 / when the sterigmata begin to form; cheilocystidia
embedded, 26-34 X 7-12 t, clavate to subcapitate, the enlarged
portion furnished with numerous wavy filamentous projections 5-10
X 1.5 g, hyaline; pleurocystidia not differentiated; gill trama vinaceous brown in iodine; pileus trama composed of a thin pellicle of very
narrow hyphae which do not gelatinize in KOH, beneath this a poorly