Mycologia 28(3): 262. 1936.
Common Name: none
Cap 70-140 mm broad, convex, becoming plano-convex, disc sometimes raised to slightly depressed in age; margin incurved, then decurved, occasionally wavy, faintly striate; surface subviscid when moist, glabrous, unevenly vinaceous to reddish brown over a pallid ground color, paler in age revealing pinkish and cream areas; context white, soft, 10-13 mm thick near the disc; odor indistinct; taste mild to moderately acrid.
Gills adnexed to adnate, close, becoming subdistant, white, maturing cream, unchanging when bruised, relatively broad, 8-10 (13) mm in width, occasionally forked near stipe, edges even; lamellulae absent.
Stipe 40-80 x 15-30 (40) mm in width, round, equal to slightly enlarged at the base; surface dry, white, obscurely wrinkled, greyish where handled near the base; context white, greying where cut; partial veil absent.
Spores 8-10.5 (11) x 6.5-8.5 microns, subglobose to broadly ellipsoid, ornamentation amyloid, composed of low warts and fine lines, seldom reticulate, amyloid; spores cream to pale yellow in deposit.
Gregarious in mixed pine-hardwood forests along the coast and low elevations of the Sierra Nevada; especially common in the San Francisco Bay Area under Monterey pine (Pinus radiata) and Bishop Pine (Pinus muricata). Fruiting from after fall rains to mid-winter.
Russula californiensis is recognized by a reddish vinaceous to reddish brown cap with blotchy pinkish-whitish areas, cream colored gills in age, and a mild to moderate acrid taste. An important though not definitive character is a greying of the lower stipe where handled, and context when cut. Several Russulas in the Russula nigricans and Russula decolorans group exhibit similar color changes, but the greying reaction and fieldmarks noted above make Russula californiensis relatively easy to identify.
Russula californiensis is common in the San Francisco Bay Area under pines, though not as common as Russula sanguinea with which it fruits and sometimes is confused. The latter differs with a brighter red, more evenly colored cap, and a blushed reddish stipe. Russula queletii, also found in this habitat, can be distinguished by a vinaceous purple cap and blushed purple stipe.
Burlingham, G.S. (1936). New or Noteworthy Species of Russula and Lactaria. Mycologia 28(3): 253-267.
Desjardin, D.E., Wood, M.G. & Stevens, F.A. (2015). California Mushrooms: The Comprehensive Identification Guide. Timber Press: Portland, OR. 560 p.