17. Ipomoea pes-caprae (Linnaeus) R. Brown in Tuckey, Narr. Exped. Zaire. 477. 1818.
厚藤 hou teng
Convolvulus pescaprae Linnaeus, Sp. Pl. 1: 159. 1753; C. bilobatus Roxburgh; C. brasiliensis Linnaeus; C. maritimus Desrousseaux; Ipomoea biloba Forsskål; I. brasiliensis (Linnaeus) G. Meyer; I. brasiliensis (Linnaeus) Sweet; I. maritima (Desrousseaux) R. Brown; I. pescaprae var. emarginata H. Hallier; I. pescaprae subsp. brasiliensis (Linnaeus) Ooststroom.
Herbs perennial, glabrous, with a thick tap root. Stems 5-30 m, prostrate, sometimes twining, rooting at nodes. Petiole 2-10 cm; leaf blade ovate, elliptic, circular, reniform or ± quadrate to oblong, 3.5-9 X 3-10 cm, rather thick, 2-glandular abaxially, base broadly cuneate, truncate, or shallowly cordate, margin entire, apex emarginate or deeply 2-lobed, mucronulate. Inflorescences 1- to several flowered; peduncle stout, 4-14 cm; bracts early deciduous, broadly deltate, 3-3.5 mm. Pedicel 2-2.5 cm. Sepals unequal, ± leathery, glabrous, apex obtuse, mucronulate; outer 2 ovate to elliptic, 5-8 mm, wider; inner 3 nearly circular and concave, 7-11 mm. Corolla purple or reddish purple, with a darker center, funnelform, 4-5 cm. Stamens included. Pistil included; ovary glabrous. Stigma 2-lobed. Capsule ± globular, 1.1-1.7 cm, glabrous, leathery. Seeds black, trigonous-globose, 7-8 mm, densely brownish tomentose. 2n = 30*.
Sandy seashores, open fields near seashores; 0-100 m. Fujian, Hainan, Taiwan, Zhejiang [Cambodia, Indonesia, Japan including Ryukyu Islands, Malaysia, Myanmar, New Guinea, Pakistan, Philippines, Sri Lanka, Thailand, Vietnam; Africa, SW Asia, Australia, North America, Pacific Islands, South America; pantropical littoral species]
According to Xing et al. (Guihaia 14: 151-156. 1994), Ipomoea pes-caprae occurs on the South China Sea Islands (Nanhai Zhudao), but no material was available for this account.
Although van Ooststroom (Blumea 3: 532-539. 1940) recognized two subspecies based on the depth of apical lobing of the leaf blades, none is accepted here. The change in growing
conditions can produce variation in leaf lobing on the same plant.
Useful as a medicinal plant (for treating colds, arthritis, and back pain), forage crop, and as a sand binder in coastal areas.