Perennials, 10-60 cm, (with crown buds). Stems erect, (unbranched) glabrous, eglandular. Leaves mostly basal; opposite (proximal) or alternate; petioles obscure (intergrading with blades); blades lanceolate to lance-linear or linear, 10-25 × 0.5-1.5 cm, bases cuneate, margins entire, faces glabrous, not gland-dotted (cauline 1-5 pairs, smaller). Heads 1(-3). Peduncles 5-10 cm. Involucres broadly hemispheric, 17-25 mm diam. Phyllaries (green with purple veins) 25-30, ovate to lance-ovate, 8-16 × 3-5 mm, apices acuminate, abaxial faces usually glabrous, sometimes puberulent. Paleae 8-9 mm, 3-toothed (middle teeth long-acuminate). Ray florets 12-17; laminae 20-40 mm, (abaxial faces not gland-dotted) . Disc florets 100+; corollas 6-6.5 mm, lobes yellow; anthers dark, appendages yellowish or dark. Cypselae 3 mm, glabrous; pappi of 2 aristate scales 1.5-2 mm plus 2-4 erose scales 0.3-0.6 mm. 2n = 34. Flowering early-late summer. Wet prairies, flatwoods; of conservation concern; 0-10+ m; Fla. Helianthus carnosus is distinctive in morphology and is known from relatively few counties in northeastern Florida.