Perennials, 50-120 cm (with crown buds). Stems erect, usually hispid to ± hirsute. Leaves mostly basal; mostly opposite; petioles 0-3 cm (broadly winged); blades (3-nerved distal to bases) ovate or lanceolate to spatulate, 6-28 × 1.2-4.3 cm, bases cuneate, margins entire (often revolute), abaxial faces hispid to ± hirsute, not gland-dotted (cauline leaves relatively few, narrowly lanceolate to linear, much smaller). Heads 1-3(-5). Peduncles 10-15 cm. Involucres broadly hemispheric, 15-25 mm diam. Phyllaries 24-30, lanceolate to lance-ovate, 8-13 × 2-5 mm, (margins sometimes ciliate) apices acute to short-acuminate or acuminate, abaxial faces sparsely hispid to glabrate. Paleae 7-9 mm, 3-toothed (apices purplish). Ray florets 12-18; laminae 14-36 mm (abaxial faces not gland-dotted). Disc florets 100+; corollas 5.5-6.5 mm, lobes reddish; anthers purplish, apendages purplish (style branches usually reddish). Cypselae 4-5 mm, glabrate; pappi of 2 aristate scales 1.7-2.5 mm plus 1-3 deltate scales 0.5-1.5 mm. 2n = 34.

Flowering late summer-fall. Wet sandy soils; 0-50+ m; Ala., Fla., Ga., La., Miss., N.C., S.C., Tex.

Helianthus heterophyllus is found on the Atlantic and Gulf coastal plains. The cauline leaves are usually abruptly reduced relative to the basal leaves; individuals sometimes have relatively large cauline leaves.