Russula albonigra
Hymenomyc. eur.: 440. 1874.
Common Name: none
For description see Schaffer, Knudsen & Vesterholt (2008), Siegel & Schwarz, and 'California Mushrooms'.
Solitary to gregarious in duff under conifers; fruiting from fall through winter in mixed conifer or hardwood-conifer forests along the north coast and in the Sierra foothills.
Unknown.
Russula albonigra is a large, robust species that begins entirely white but soon turns black overall, without going through a red staining phase. Mushrooms can be found in various stages of blackening, usually with the gills remaining white longer than the cap or stipe. The only other species in California likely to be confused with Russula albonigra is Russula atrata, which also forms robust white fruitbodies that soon turn black and lack a red staining phase; however, Russula atrata has a thicker gelatinous pileipellis, which can be distinguished only through microscopic analyses. For species that turn red then black, see Russula densifolia and Russula cantharellicola.
Arora, D. (1986). Mushrooms Demystified. Ten Speed Press: Berkeley, CA. 959 p.
Desjardin, D.E., Wood, M.G. & Stevens, F.A. (2015). California Mushrooms: The Comprehensive Identification Guide. Timber Press: Portland, OR. 560 p.
Knudsen, H. & Vesterholt, J. ed. (2008). Funga Nordica: Agaricoid, boletoid and cyphelloid genera. Nordsvamp: Copenhagen, Denmark. 965 p. (PDF)
Knudsen, H. & Vesterholt, J. ed. (2012). Funga Nordica: Agaricoid, boletoid, clavarioid, cyphelloid and gastroid genera. Vol. 1. Nordsvamp: Copenhagen, Denmark. 511 p.
Shaffer, R.L. (1962). The subsection Compactae of Russula. Brittonia 14: 254-284. (PDF)
Siegel, N. & Schwarz, C. (2016). Mushrooms of the Redwood Coast. Ten Speed Press: Berkeley, CA. 601 p.
