Cap: 7.5-15 cm wide, fleshy, firm, broadly umbilicate or centrally depressed, becoming somewhat infundibuliform, downy-tomentose, white, often with yellowish stains or becoming yellowish or tawny-yellow with age, the margin at first strongly involute, latex abundant, pale creamy-yellow, taste very acrid;
Gills: narrow, crowded, often forked, adnate or slightly decurrent, pale creamy yellow, becoming tawny when wounded, stem short, equal or tapering downward, solid, white, downy.
Stem: 1.8-4.8 cm long, 1.2-2.5 cm thick, tapered at base.
Spores: subglobose, rugose, about 7.5 µm long, white or cream color, dotted with small warts.
Found on dry ground in mixed woods. Summer.
(Description adapted from Bull. Torrey bot. Club 25:369,1898)
According to Zhang and Feng (1997b), the ethyl acetate extract of Lactarius subvellereus has cytotoxic and antitumor activities, citing Jing and Xiaozhang, Acta Pharmaceutica Sinica (I have not been able to locate this reference).
Three novel lactones have been isolated from the fruiting bodies of L. subvellereus, including lactariolide, a 14-membered-ring lactone ((R)-13-hydroxy-trans- 9,11-octadecadienoic acid lactone) (Zhang and Feng, 1997a), subvellerolactone A (13-hydroxy-lactara- 6,8-dien-5-oic acid γ-lactone) (Zhang and Feng, 1997b), and subvellerolactone C (3,8-oxa-13-hydroxy- lactar-6-en-5-oic acid γ-lactone) (Zhang and Feng, 1996). The latter two structures are shown below.
The sesquiterpene lactone subvellerolactone A from L. subvellereus. Note the γ-hydroxy-α,β-unsaturated butenolide system, with the double bond at the junction of the rings, all in a lactarane skeleton.
The lactarane sesquiterpene subvellerolactone C.
Polysaccharides extracted from the mycelial culture of L. subvellereus and administered intraperitoneally into white mice at a dosage of 300 mg/kg inhibited the growth of Sarcoma 180 and Ehrlich solid cancers by 70% and 60%, respectively (Ohtsuka et al., 1973).
New biologically active metabolites from Chinese higher fungi.
Curr Org Chem. 2006 10(8):849-71.
Ohtsuka S, Ueno S, Yoshikumi C, Hirose F, Ohmura Y, Wada T, Fujii T, Takahashi E.
Polysaccharides having an anticarcinogenic effect and a method of producing them from species of Basidiomycetes.
UK Patent 1331513, 26 September 1973.