Leaf blades 3-nerved distal to bases, 20-50 × 15-30 mm, broadest near bases, bases broadly cuneate to cuneate, margins serrate. 2n = 20, 30. Flowering Jul-Aug. Disturbed sites; 10-100+ m; Ala., Ark., Fla., Ga., La., Miss., Mo., Okla., S.C., Tex. Variety scabridum includes apomictic polyploids and has been suggested to have been derived from hybridization between var. rotundifolium and Eupatorium semiserratum.