Biennials, 50-180 cm; taproots short with many slender, fibrous lateral roots. Stems usually single, erect, glabrous to ± tomentose, sometimes sparsely villous with septate trichomes; branches few, usually distal, ascending. Leaves: blades linear to oblanceolate or elliptic, 10-30 × 1-5 cm, unlobed and spinulose to irregularly dentate or pinnatifid, lobes narrowly to broadly triangular, sometimes coarsely toothed or lobed toward base, acuminate, main spines slender, 1-5 mm, abaxial faces gray-tomentose, adaxial glabrous or sparsely villous with septate trichomes; basal often present at flowering, petioles slender, winged, bases long-tapered; principal cauline relatively few (10-25), petiolate or distal sessile, mostly restricted to proximal 1/2 of stems, progressively reduced distally, bases tapered, not decurrent; distal cauline widely separated, linear to narrowly elliptic, reduced, becoming ± bractlike, merely spinulose to irregularly dentate or shallowly lobed. Heads (1-)2-9(-many), in paniculiform arrays. Peduncles slender, 1-15 cm (not overtopped by distal leaves. . Involucres narrowly ovoid to campanulate, 1.2-2 × 1.2-2 cm, thinly arachnoid-ciliate. Phyllaries in 7-10 series, imbricate, green, linear to lanceolate (outer) or linear to linear-lanceolate (inner), abaxial faces with narrow, glutinous ridge; outer and middle ascending to appressed, bodies entire, apices widely spreading (at least the outer), spines ascending to spreading (at least the outer), slender, 1-4 mm; apices of inner phyllaries flat, often twisted, acuminate. Corollas pink-purple (white), 15-20 mm, tubes 5-9 mm, throats 5-7 mm (noticeably wider than tubes. , lobes 4-5 mm; style tips 4 mm. Cypselae light brown, 3-4 mm, apical collars yellowish, 0.5-1 mm; pappi 12-14 mm. 2n = 20, 22. Flowering spring-summer (Apr-Jul). Wooded areas, openings, fields, roadsides; 50-300 m; Ala., Ark., Ga., Ill., Ind., Ky., La., Miss., Mo., N.C., Ohio, Okla., S.C., Tenn., Tex. Cirsium carolinianum is widely distributed in the southeastern United States: on the Gulf coastal plain from Texas to Alabama north through the Ouachita and Ozark highlands to southeastern Missouri; in the Ohio River Valley from southernmost Illinois to southern Ohio and northern Kentucky; and in the southern Appalachians and Piedmont from Alabama and Tennessee to southern Virginia. Cirsium carolinianum, though widespread, is a taxon of conservation concern over part of its range. The replacement of open woods by dense forests brought about by fire suppression has greatly reduced available habitat.
Slender, fibrous-rooted biennial 5-15(-18) dm; stem glabrous or arachnoid, sometimes more evidently tomentose when young; lvs closely white-tomentose beneath, glabrous or hirsute on the upper surface, from merely spinose-ciliate and up to ca 2.5 cm wide to evidently pinnatifid and to 5 cm wide, the basal ones to 3 dm, the cauline relatively few, mostly 10-25, 8-15 cm and (except when lobed) seldom more than 1.5 cm wide, narrow-based, reduced upward; heads (1-) several, on long, naked peduncles terminating the branches; invol 1.5-2 cm, its middle and outer bracts with a glutinous dorsal ridge and a slender, suberect or spreading spine 1.5-4 mm, the
inner merely attenuate and commonly crisped; fls pink-purple; achenes 3-4 mm; 2n=20. Open woods and dry, sandy soil; s. O. to the mts. of N.C., Ga., and Ala., w. to Mo. and Tex. May, June. (C. flaccidum)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.