Summary:
Clade Russula crown. Features include 1) a red-brown to dark brown to orange-brown or yellow-brown, viscid cap that peels halfway to center, 2) white unchanging flesh, 3) close yellowish gills, 4) a white stem washed with red or reddish brown on its lower part, 5) a very peppery taste, and 6) an ochraceous spore deposit. Russula mordax is common in the Pacific Northwest but it has been known under the misapplied name Russula veternosa (see NOTES on that species). Singer expresses the conviction that R. mordax is R. badia Quel., in spite of the fact that Burlingham says Russula mordax differs in the taste being instantly acrid, the gills not sinuate, in the lack of odor, and in the color, shape, size, and markings of the spores. Russula tenuiceps Kauffman from eastern North America is similar and that name would have priority if they are the same species.

Gills:
abruptly narrowed next to the stem, rounded at outer end, close, equal, many forking near stem and a few near or part way to margin, interveined; maize yellow tone 1, (Burlingham), "crowded, equal, many forking at base; yellowish", (Phillips), adnexed to adnate, close, rarely subdistant, some forking near the stem, subgills scattered and of various lengths; pale yellow to yellow, (Thiers)

Stem:
8cm long and 3cm wide, nearly equal, blunt at base; "washed with red, more deeply colored in same places", paler at junction with gills, (Burlingham), 4-8cm x 1.5-3cm, equal; white washed with red or reddish brown in lower part, paler at top, (Phillips), 4.5-8cm long, 1-3cm wide at top, equal or widening slightly downward, stuffed to solid; "white with reddish flushes particularly at the base", unchanging when old; dry, bald, (Thiers)

Odor:
none (Burlingham, Phillips), mild (Thiers), often with a floral odor (D. Miller, pers. comm.)

Taste:
very peppery (Burlingham, Phillips, Thiers)

Microscopic spores:
spores 7.5-8.75 x 6.5-7.5 microns, with protuberances of varying size, many connected by bands or fine lines, apiculate, (Burlingham), spores 7-9.5 x 6-7.5 microns, elliptic, warts 0.4-0.8 microns high, "connected by bands and an occasional fine line"; pleurocystidia 67-78 x 6-12 microns, "clavate, acute or appendiculate, banded", cheilocystidia 52-63 x 4-6 microns, "clavate or subcylindric, acute or nearly appendiculate, empty or banded"; subhymenium of small cells; epicutis of the emetica type: pileocystidia conspicuous; hypodermium distinct, (Hesler), spores 7.7-10.2 x 6-8.5 microns, ornamentation about 0.9 microns high, type IIIa, some IIIb; basidia about 50 x 10-10.5 microns, cystidia 50-60 x 6.6-10 microns, "rather numerous, with banded contents, versiform"; dermatocystidia numerous, (Singer), spores 7-9.5 x 6-7.5 microns, ovoid, warts up to 0.8 microns high, connected by fine partial reticulum, (Phillips), spores 8.5-11 x 7-8.5 microns, suboval to subelliptic, rarely nearly round, ornamentation "of numerous isolated spines and conspicuous heavy ridges and fine lines sometimes forming a partial reticulum", warts 0.4-1.0 microns high; hymenial cystidia scattered to rare, 50-70 x 4-10 microns, embedded in hymenium except for apical part, "subclavate to fusoid with a subacute to acute apex or a short, narrowed, terminal appendage"; cap cuticle 65-90 microns, "epicutis differentiated as a relatively narrow trichodermium with rather closely interwoven hyphae with free hyphal tips and well differentiated, clavate to subclavate pileocystidia", (Thiers)

Spore deposit:
ochroleucous (Burlingham), ochraceous, Crawshay D-F, (Phillips), yellow (Thiers)

Notes:
Burlingham described this species originally from Seattle WA. Phillips also found it in WA. Molecular study of Ben Woo''s collections revealed sequences from WA, OR, and ID. It is likely that at least some of the collections at the University of British Columbia labeled Russula veternosa are likewise really Russula mordax. One of them, an O. Ceska collection from Victoria, BC, has a DNA sequence that matches the type of R. mordax (Mushroom Observer 83025). Thiers gives R. veternosa for CA (one collection).

EDIBILITY

no

Synonyms and Alternate Names:
Russula veternosa Fr. (misapplied name)