Biennials, 30-200(-300) cm; taproots. Stems 1-many, erect or ascending, branches few-many, ascending, villous with septate trichomes. Leaves: blades oblong-lanceolate to obovate, 15-40 × 6-15 cm, margins plane or revolute, coarsely 1-2-pinnatifid with rigidly divergent lobes, sometimes merely spinose-dentate, lobes triangular to lanceolate, entire to spiny-dentate, main spines 2-10 mm, abaxial faces gray-tomentose, villous with septate trichomes along veins, adaxial green, covered with short appressed bristlelike spines, sometimes tomentose when young; basal present or absent at flowering, petioles winged, bases tapered; principal cauline winged-petiolate, mid and distal becoming sessile, well distributed or not, progressively reduced distally, at least distal decurrent as long spiny wings; distal cauline often more deeply lobed than proximal, main lobes rigidly spiny, margins spinulose, otherwise entire. Heads few-many in corymbiform or paniculiform arrays. Peduncles 1-6 cm. Involucres hemispheric to campanulate, 3-4 × 2-4 cm, loosely arachnoid-tomentose. Phyllaries in 10-12 series, strongly imbricate, linear-lanceolate (outer) to linear (inner), outer and middle appressed, (bases stramineous), margins entire, abaxial faces without glutinous ridge, apices radiating, greenish, spines 2-5 mm; apices of inner phyllaries flat, serrulate to minutely erose. Corollas purple (rarely white), 25-35 mm, tubes 18-25 mm, throats 5-6 mm, lobes 5-7 mm; style tips 3.5-6 mm. Cypselae light brown with darker streaks, 3-4.5 mm, apical collar not differentiated; pappi 20-30 mm. 2n = 68. Flowering mostly summer (Jun-Sep), year round in areas with mild climates. Invasive weed of disturbed sites, pastures, meadows, forest openings, roadsides; 0-2200 m; introduced; St. Pierre and Miquelon; Alta., B.C., Man., N.B., Nfld. and Labr. (Nfld.), N.S., Ont., P.E.I., Que., Sask.; Ala., Alaska, Ariz., Ark., Calif., Colo., Conn., Del., D.C., Fla., Ga., Idaho, Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., Mont., Nebr., Nev., N.H., N.J., N.Mex., N.Y., N.C., N.Dak., Ohio, Okla., Oreg., Pa., R.I., S.C., S.Dak., Tenn., Tex., Utah, Vt., Va., Wash., W.Va., Wis., Wyo.; Eurasia.
Biennial weed 5-15 dm; stem conspicuously spiny- winged by the decurrent lf-bases, copiously spreading-hirsute to sometimes arachnoid; lvs strongly spiny, pinnatifid, the larger ones with the lobes again toothed or lobed, scabrous-hispid above, thinly white-tomentulose to sometimes green and merely hirsute beneath; heads several, purple; invol 2.5-4 cm, its bracts all spine-tipped, without any well developed glutinous dorsal ridge; achenes 3-4 mm; 2n=68. Pastures, fields, roadsides, and waste places; native of Eurasia, now widely established in N. Amer. June-Oct. (C. lanceolatum, misapplied)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
©The New York Botanical Garden. All rights reserved. Used by permission.
Duration: Biennial Nativity: Non-Native Lifeform: Forb/Herb Synonyms: Carduus lanceolatus, Carduus vulgaris, Cirsium lanceolatum