Description from Flora of China
Convolvulus turpethum Linnaeus, Sp. Pl. 1: 155. 1753; Argyreia alulata Miquel; Convolvulus anceps Linnaeus; Ipomoea anceps (Linnaeus) Roemer & Schultes; I. turpethum (Linnaeus) R. Brown; I. turpethum var. anceps (Linnaeus) Miquel; Merremia turpethum (Linnaeus) Bojer; Operculina turpethum var. heterophylla H. Hallier; Spiranthera turpethum (Linnaeus) Bojer.
Herbs perennial. Roots fleshy, long, much branched. Stems reddish, to 4 m, narrowly 3-5-winged, ± angular, gla-brous or densely pilose-tomentose on young parts. Petiole 2-10 cm, often winged; leaf blade cordate-circular, ovate, broadly ovate, ovate-lanceolate, or lanceolate, 4-14 X 3.5-14 cm, abaxially pubescent, adaxially appressed pilose to gla-brous, base cordate, truncate or obtuse, margin entire or undulate, apex acute or acuminate, mucronulate. Inflorescences cymose, often 2-flowered; peduncles 0.5-3 cm, usually terete; bracts 2, oblong to ovate-oblong, 1-2.5 cm, concave, pubescent. Pedicel 1.5-2 cm, striate-angular, clavate, to 4 cm in fruit. Sepals ovate to broadly ovate, unequal; outer 2 sepals 1.5-2 cm, abaxially pubescent; inner 3 shorter, subglabrous. Corolla white, sometimes with a yellowish base inside, broadly funnelform, 3.5-4 cm, glabrous, minutely yellowish glandular outside; limb 5-lobed. Filaments pubescent basally; anthers twisted. Fruit enclosed in cupular calyx, depressed globose, ca. 1.5 cm in diam. Seeds dull black, ovoid-trigonous, ca. 6 mm, glabrous. Fl. and fr. year round. 2n = 30.
The leaves and roots are used medicinally.
Streambanks, roadsides, grassy fields, wasteland, dry slopes, clay and sandy soils, scrub bordering valleys; 0-500 m. Guangdong, Guangxi, Hainan, Taiwan, S Yunnan [?Bangladesh, Cambodia, India, Indonesia, Japan (Ryukyu Islands), ?Laos, Malaysia, Myanmar, Nepal, New Guinea, ?Pakistan, Philippines, Sri Lanka, Thailand, Vietnam; E Africa, Australia, introduced in North and South America (West Indies), Pacific Islands]