|Major Groups > Gilled Mushrooms > Dark-Spored > Agaricus > Agaricus bernardii|
by Michael Kuo
Originally described from seaside dunes in France, Agaricus bernardii has since been found in other maritime ecosystems in Europe, on the Pacific and Atlantic coasts of our continent . . . and in Denver. Perhaps an enterprising Denver lawn care business imported sod or sand from a coastal area, or perhaps Agaricus bernardii is capable of adapting to diverse ecosystems.
The salient features of Agaricus bernardii--taught to me by Ellen Jacobson of the Colorado Mycological Society--include the sheathlike (rather than skirtlike) ring; the tough, red-staining flesh; the subscaly mature cap surface; and the inrolled cap margin. Microscopic features (see below) will confirm identification.
Ecology: Saprobic; growing alone, scattered, or gregariously in sand dunes, drainage areas near coastal and brackish waters, and under Monterey Cypress; also in lawns and grassy areas (and then sometimes forming fairy rings); summer and fall (or over winter in California); recorded along the Pacific and Atlantic coasts, and in Denver.
Cap: 5-21 cm; convex to broadly convex; whitish and fairly smooth when young, becoming cracked or subscaly and often developing brownish colors; dry; the margin strongly inrolled.
Gills: Free from the stem; close; pink becoming brown and then dark chocolate brown in maturity; covered with a white partial veil when in the button stage.
Stem: 4-13 cm long; up to 4 cm (or more) thick; more or less equal, or tapering to base when mature; with a sheathing white ring; solid; whitish to brownish, bruising reddish; smooth or finely hairy.
Flesh: Whitish; usually changing to pinkish or reddish when sliced; not yellowing, even in the base of the stem.
Odor and Taste: Mild (inland collections) or pungent and briny.
Chemical Reactions: Cap surface negative with KOH.
Spore Print: Dark chocolate brown.
Microscopic Features: Spores: 5-8 x 5-6.5 µ; elliptical. Cheilocystidia up to 60 x 17 µ; cylindrical; flexuous.
Agaricus halophilus Peck may be a synonym.
Agaricus bitorquis is quite similar, but does not stain red.
Further Online Information:
Cite this page as:
Kuo, M. (2007, October). Agaricus bernardii. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/agaricus_bernardii.html