Plants 40-140 cm; taproots thickened, tuberous. Stems 1-5, erect, mostly green with mottled purple, slender, simple, glabrous. Leaves: proximal present at flowering; petiolate (petioles winged); blades oblong to linear, 7-18 × 0.5-6 cm, coriaceous, bases attenuate, margins deeply pinnately lobed or divided, lobes narrow and at right angles, apices acute to acuminate, faces glabrous or slightly glabrate along veins; distally sessile and much reduced. Heads (1-2 in pedunculate lateral clusters) in spiciform or racemiform arrays. Involucres cylindro-campanulate, 10-13 × 3-4 mm. Calyculi of 6-8, green to purple, triangular to subulate bractlets 1-4 mm. Phyllaries 7-8, pink or purple, linear to elliptic, 8-13 mm, glabrous. Florets 8-10; corollas usually pinkish. sometimes lavender or white, 11-17 mm. Cypselae dark green, elliptic to linear, subterete to angular, 3.5-5.5 mm, indistinctly 8-10-ribbed; pappi pale yellow to tan, 5 mm. Flowering Aug-Oct. Coastal plain, low savannas, sandy pinelands, moist places, swales; 0-200 m; Del., Fla., Ga., Md., Miss., N.J., N.C., S.C., Va. Prenanthes autumnalis is recognized by its erect, slender habit, pinnately lobed proximal leaves, narrowly racemiform or spiciform arrays of heads, glabrous phyllaries, and usually pinkish corollas.
Plants 4-14 dm, glabrous throughout; basal and lowermost cauline lvs elongate, 7-35 נ1-12 cm, few-toothed to generally pinnately lobed, the lobes often rather narrow and distant; cauline lvs conspicuously reduced upward, often becoming linear and entire; infl very narrow and elongate, either subracemiform, or in more robust plants with closely ascending, subracemiform branches; heads nodding; invol 10-13 mm, generally purplish, without long hairs, with mostly 8 principal bracts, the reduced outer ones often passing into those of the slender peduncle; fls (8-)10-11(-13), pink or pale lavender; pappus stramineous. Sandy, usually moist places, often among pines; coastal plain from N.J. to n. Fla. Aug.-Oct. (P. virgata)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.