Description from Flora of China
Convolvulus indicus J. Burman, Index Univ. Herb. Amb. 7: 6. 1755; C. acuminatus Vahl; C. congestus (R. Brown) Sprengel; Ipomoea acuminata (Vahl) Roemer & Schultes; I. amoena Blume; I. cataractae Endlicher; I. cathartica Poiret; I. congesta R. Brown; I. insularis (Choisy) Steudel; I. kiuninsularis Masamune; I. learii Paxton; I. mutabilis Lindley; Parasitipomoea formosana Hayata; Pharbitis acuminata (Vahl) Choisy; P. acuminata var. congesta (R. Brown) Choisy; P. cathartica (Poiret) Choisy; P. indica (J. Burman) R. C. Fang; P. insularis Choisy; P. learii (Paxton) Lindley.
Herbs twining or sometimes prostrate, with ± densely retrorse pilose axial parts. Stems 3-6 m, sometimes rooting at nodes. Petiole 2-18 cm; leaf blade ovate or circular, 5-15 X 3.5-14 cm, abaxially densely short, soft, pubescent, adaxially ± sparsely pubescent, base cordate, margin entire or ± 3-lobed, apex acuminate or abruptly acuminate. Inflorescences dense umbellate cymes, several flowered; peduncle 4-20 cm; bracts linear, sometimes lanceolate. Pedicel 2-5(-8) mm. Sepals subequal, 1.4-2.2 cm, gradually linear-acuminate apically, glabrous to appressed pilose; outer 3 lanceolate to broadly lanceolate; inner 2 narrowly lanceolate. Corolla bright blue or bluish purple, aging reddish purple or red, with a paler center, funnelform, 5-8 cm, glabrous. Stamens included. Pistil included; ovary glabrous. Stigma 3-lobed. Capsule ± globose, 1-1.3 cm in diam. Seeds ca. 5 mm. 2n = 30*.
Fosberg (Bot. Not. 129: 35-38. 1976) has sorted out the complicated nomenclature for this pantropical species and established that Ipomoea indica is the correct name for it.
Coastal habitats, moist forests, weedy; 0-500 m. Guangdong, Hainan (Nanhai Zhudao), Taiwan [Indonesia, Japan, Malaysia, Myanmar, New Guinea, Pakistan, Philippines, Sri Lanka; Pacific Islands, native of South America, now circumtropical as a cultivated and naturalized plant]