Helianthus heterophyllus Nutt.

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.

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.

Helianthus elongatus Small

Helianthus heterophyllus is a species of sunflower known by the common names variableleaf sunflower and wetland sunflower. It is native to the coastal plain of the southern United States from Texas to North Carolina.

Helianthus heterophyllus is a perennial sometimes as much as 120 cm (4 feet) tall, spreading by means of underground rhizomes. Leaves and stems are hairless or almost hairless; leaves appear white on the undersides because of an abundance of wax. One plant can produce 1-5 flower heads, each with 12–18 yellow ray florets surrounding as least 100 red or brown disc florets. The species grows in wet sandy soils at low elevations.

Helianthus heterophyllus là một loài thực vật có hoa trong họ Cúc. Loài này được Nutt. mô tả khoa học đầu tiên năm 1834.