Plants 30-60 cm. Stems sprawling to weakly erect, strigose to hirsute. Leaf blades ovate or 3-lobed, 1.5-4 × 1-1.5 cm, bases broadly ± cuneate, hastate, margins coarsely serrate (sometimes undulate), faces strigose to hispid. Heads borne singly. Peduncles 2.5-10 cm, hispid to strigose. Involucres 10-14 mm diam. Phyllaries lanceolate, 5-7 × 1.5-3 mm. Paleae 6-7 × 2 mm, apical mucros 1-1.5 mm, usually recurved. Florets 25-40; corollas 5 mm; anther sacs 1.5 mm. Cypselae 2.5-3 × 1.5-2 mm. 2n = 30.

Flowering Feb-Apr (perhaps year-round). Old coral reefs or porous oölitic rocks in open pine forests; 0-10+ m; Fla.

Melanthera parvifolia is known only from southern Florida, including Big Pine Key.