North American Flora 10(4): 259. 1924.
Common Name: none
Cap 2.5-6.5 cm broad, conic, becoming bell-shaped, finally nearly plane with a distinct umbo, margin sometimes uplifted in age; surface dry, radially fibrillose to cracked, pale yellowish-buff, shading to a slightly darker disc, flesh thin, pallid to buff; odor of green corn.
Gills close, narrow, adnate, sometimes seceding, pallid to drab buff, becoming dull brown at maturity, edges lighter than the faces.
Stipe 4-10 cm tall, 0.3-0.8 cm thick, equal to slightly enlarged at the base, surface dry, fibrillose, pallid to concolorous with the cap; veil absent.
Spores 10-14 x 6-8 µm, elliptical, smooth. Spore print dull brown.
Solitary to scattered under hardwoods and conifers; in our area it is common with Monterey pine; fruiting from late fall to mid-winter.
Toxic. Contains a clinically significant concentration of muscarine.
In a genus known for small, drab, difficult to differentiate mushrooms, Inocybe sororia stands out because of its relatively large size and conic cap with a well developed umbo. Other important field characters are the radially fibrillose to cracked cap surface and the strong green corn odor obvious when the cap tissue is crushed.
Ammirati, J.F., Traquair, J.A. & Horgen, P.A. (1985). Poisonous Mushrooms of the Northern United States and Canada. University of Minnesota Press: Minneapolis, MN. 396 p.
Desjardin, D.E., Wood, M.G. & Stevens, F.A. (2015). California Mushrooms: The Comprehensive Identification Guide. Timber Press: Portland, OR. 560 p.
Kauffman, C.H. (1924). Inocybe. N. Am. Flora 10(4): 227-260. (Protologue)
Smith, A.H. (1949). Mushrooms in their Natural Habitats. Sawyer's Inc: Portland, OR. 626 p.
Stuntz, D. (1947). Studies in the Genus Inocybe. I. New and Noteworthy Species from Washington. Mycologia 39: 21-55.