Inocybe sororia Kauffman 1924

Inocybe sororia C. H. Kauffman, sp. nov
Pileus thin, subconic to conic-campanulate, then expanded-umbonate, subconic or acute, 2-5 (-7) cm. broad; surface dry, innately silky-fibrillose, at length long-rimose, at first creamcolored (R) to straw-yellow (R) or mustardyellow (R), sordid and darker with age, the umbo darker, prominent; margin at length split and recurved; context pallid or yellowishtinted, dingy with age, the odor somewhat pungent or lacking; lamellae attenuateadnate, rather narrow, varying 2-5 mm. wide, close to crowded, at first whitish or yellowtinted, then olivebuff (R) to mustard-yellow (R) or old-gold (R), the edges white-fimbriate; stipe strict, equal or tapering upward above the rounded, subbulbous base, the bulb subobsolete, at first silkycortinate, glabrescent, innately fibrillose, solid, pruinose at the apex, whitish, becoming dingy with age, 3-7 cm. long, 2-4 (-5) mm. thick; spores elliptic or elongateellipsoid, not truly sub-
reniform,subinequilateral, obtuse at both ends, very variable in size, 9-13 (-16) X 5.5-6 (-8) m; cystidia none; sterile cells clavate, on the edges of the lamellae.
Type collected on the ground in frondose woods, Ann Arbor, Michigan, July 23, 1920, D, V. Baxter (herb. Univ. Mich.).
Distribution: New England to Virginia, and westward to Oregon and Washington.