Stems glabrous or slightly tomentose. Leaves: basal wing-petioled, blades 15-60+ cm, margins coarsely lobed; cauline leaves clasping, progressively smaller and less divided, bases spiny, coiled, auriculate. Phyllary appendages spreading, ovate, 1-4 cm including long-tapered spine tips. Corollas 26-35 mm; tubes 13-25 mm, throats campanulate, 2-3 mm, lobes 5-9 mm. Cypselae brown and black spotted, 6-8 mm; pappus scales 15-20 mm. 2n = 34. Flowering Feb-Jun (west), Jul-Sep (north). Roadsides, pastures, waste areas; sometimes cultivated; 0-800 m; introduced; Alta., B.C., N.B., N.S., Ont., Que., Sask.; Ala., Ariz., Ark., Calif., Conn., Ind., La., Mich., Miss., Nev., N.H., N.J., N.Mex., N.Y., N.C., Ohio, Oreg., Pa., Tenn., Tex., Vt., Va., Wash., W.Va.; s Europe (Mediterranean region). Silybum marianum is sometimes cultivated as an ornamental, a minor vegetable, or as a medicinal herb. Young shoots can be boiled and eaten like cabbage and young leaves can be added to salads. The seeds can be used as a coffee substitute. Extracts of S. marianum are used as an herbal treatment for liver ailments.
Glabrous or slightly tomentose, 6-15 dm; lvs pinnately lobed, less so upwards, to 4 dm and nearly half as wide, petiolate below, becoming sessile and strongly auriculate-clasping above, spiny-margined, ±marked with white along the main veins; coarse, spreading tips of the invol bracts basally expanded; disk 3-6 cm wide; achenes 6-7 mm; 2n=34. A weed in waste places and about ballast-dumps; native of the Mediterranean region, rarely seen here and there in our range. May-July. (Mariana m.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.