Convolvulus imperati Vahl, Symb. Bot. 1: 17. 1790; Batatas acetosifolia (Vahl) Choisy; B. littoralis (Linnaeus) Choisy; Convolvulus acetosifolius Vahl; C. littoralis Linnaeus; C. sinuatus Petagna; C. stoloniferus Cirillo; Ipomoea acetosifolia (Vahl) Roemer & Schultes; I. carnosa R. Brown; I. littoralis (Linnaeus) Boissier; I. stolonifera (Cirillo) J. F. Gmelin.

Herbs perennial, glabrous. Stems trailing, to 5 m, rooting at nodes. Petiole 0.5-4.5 cm; leaf blade variable, often linear, lanceolate, oblong, or ovate on same plant, 1.5-3 X 0.8-2 cm, rather fleshy, base truncate or shallowly cordate, margin entire, undulate, or 3-5-lobed; middle lobe ovate to oblong, lateral lobes smaller, apex obtuse or emarginate to 2-lobed. Flowers usually solitary, occasionally 2 or 3 together; peduncle ca. 2 cm; bracts deltate, ca. 2 mm. Pedicel 0.7-1.5 cm, stout. Sepals oblong, unequal, ± leathery, glabrous, apex obtuse or acute, mucronulate; outer 2 sepals 7-11 mm; inner ones to 1.5 cm. Corolla white, with a pale yellow tube and a dark red center, funnelform, 3.5-4 cm, glabrous. Stamens included. Pistil included; ovary glabrous. Stigma 2-lobed. Capsule ± globose, ca. 1 cm, smooth, glabrous. Seeds ca. 8 mm, tomentose, margin with longer hairs. 2n = 30.

La Valva and Sabato (Taxon 32: 110-114. 1983) have established that Ipomoea stolonifera (Cirillo) J. F. Gmelin, the name by which this species has long been known, is illegitimate, because it is based on the same type as the earlier Convolvulus sinuatus Petagna. Unfortunately, the latter epithet cannot by taken up in Ipomoea because of the later I. sinuata Ortega.

Coastal sandy beaches, dunes, grasslands; 0-100 m. Fujian, Guangdong, S Guangxi, Hainan, Taiwan [Indonesia, Japan (Ogasawara and Ryukyu Islands), Malaysia, Philippines, Sri Lanka, Thailand, Vietnam; Africa, Australia, Europe, North America, Pacific Islands; a pantropical and warm temperate littoral species]