Leaf blades 3-15 × 0.5-4 cm. Involucres 1-4 cm diam. Phyllaries spreading to reflexed, green, linear to lanceolate, herbaceous. Ray laminae spreading, eventually reflexed, elliptic to obovate, 12-30 × 7-15 mm, abaxially hirsute. Disc corollas 2.8-3.5 mm. Cypselae: each face 4-5-striate and minutely cross-rugose, glabrous; pappi 0 (cypselae each with ring of tan tissue at apex, ca. 0.1 mm). 2n = 32. Flowering late spring-summer. Open sites, moist soils; 0-400 m; Ala., Ark., Fla., Ga., Ill., Kans., La., Miss., Mo., N.Mex., N.Dak., Okla., S.C., Tex. Rudbeckia amplexicaulis grows mainly in the Gulf coastal plain and Mississippi Embayment. It may be adventive elsewhere. It is used in 'native' meadow and roadside plantings and has become a problem in some agricultural crops.