Biennials or perennials, 60-150(-200) cm; crown sprouts from cluster of fibrous roots, these often tuberous-thickened. Stems usually single, erect, thinly appressed-tomentose, ± glabrate in age; branches 0-few in distal 1/3, ascending. Leaves very numerous, firm-textured, blades 3-15 cm, thick, ± rigid, linear or linear-elliptic, 0.5-2 cm wide and spinulose, or narrowly ovate, 2-4 cm wide, deeply lobed, lobes remote, spreading, separated by broad sinuses, few toothed or lobed, margins often revolute, main spines slender, 3-5(-9) mm, abaxial faces white-tomentose, adaxial green, glabrous or thinly tomentose; basal usually absent at flowering, winged-petiolate; proximal cauline usually absent at flowering, well separated, winged-petiolate; middle and distal numerous (30-70+), sessile, well distributed, gradually reduced distally, bases tapered, not decurrent; distal linear, entire or few lobed, ca. 1 cm. Heads 1-10+ in open, corymbiform or paniculiform arrays. Peduncles 10-15 cm (not overtopped by distal leaves). Involucres ovoid to cylindric or narrowly campanulate, 1.7-2.4 × 1-2 cm, glabrous or outer phyllaries very thinly tomentose. Phyllaries in 8-13 series, strongly imbricate, light green to brownish with dark apices, ovate (outer) to narrowly linear-elliptic (inner), abaxial faces with evident, narrow glutinous ridge; outer and middle appressed, bodies entire, apices erect or spreading, muticous to short-spinose, spines ascending to spreading, weak, 1-2 mm; apices of inner all straight and entire or innermost ± flexuous, erose. Corollas purple, 21-26 mm, tubes 8.5-11 mm, throats 6-8 mm (noticeably wider than tubes. , lobes 4-8 mm; style tips 3.5-5 mm. Cypselae dark brown, 4-5 mm, apical collars yellowish, 0.5-1; pappi 17-20 mm. 2n = 28. Flowering summer-fall (Aug-Oct). Moist savannas, pine barrens, coastal plain bogs; 0-150 m; Del., Fla., Ga., N.J., N.C., S.C., Va. Cirsium virginianum occurs on the Atlantic coastal plain from Delaware to Florida.
Slender biennial 5-10(-15) dm from a cluster of fleshy- fibrous roots; stem glabrous or arachnoid, sometimes more evidently tomentose when young; lvs closely white- tomentose beneath, glabrous or hirsute on the upper surface, the basal ones soon deciduous, the others numerous, mostly 30-70, 5-20 cm, sometimes merely spinose-ciliate and up to 1 cm wide, sometimes evidently pinnatifid and to 5 cm wide; peduncles with a few reduced lvs or bracts; heads as in no. 8 [Cirsium carolinianum (Walter) Fernald & B. G. Schub.], but avg larger, the invol to 2.5 cm; 2n=28. Savannas, bogs, and wet pinelands; coastal plain from s. N.J. to Fla. Aug., Sept. (C. revolutum)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.