1. CONVOLVULACEAE (旋花科)
2. Xenostegia
3. Xenostegia tridentata (尖萼鱼黄草 )

Convolvulus tridentatus Linnaeus, Sp. Pl. 1: 157. 1753; Evolvulus tridentatus (Linnaeus) Linnaeus; Ipomoea tridentata (Linnaeus) Roth; Merremia hastata H. Hallier; M. tridentata (Linnaeus) H. Hallier; M. tridentata subsp. hastata (H. Hallier) van Ooststroom.

Herbs repent or twining, with a stout root. Stems wiry, to 4 m, ± angular to narrowly winged, glabrous. Petiole 1-3 mm or absent; leaf blade narrowly oblong, linear-oblong, to linear, dilated toward base, 2.5-8 cm X 4-15 mm, subglabrous, base hastate, ± clasping stem, basal lobes dentate, gradually attenuate to apex, apex acute or obtuse, mucronulate. Cymes 1-3-flowered; peduncle (1-)5-6 cm, slender, pubescent basally, glabrescent distally; bracts minute, subulate. Pedicel 6-8 mm. Sepals ovate-lanceolate, equal in length or outer 2 shorter, 6-8 mm, glabrous, apex attenuate-acuminate forming a sharp point. Corolla pale yellowish or white, with or without a maroon to brown center, funnelform, ca. 1.6 cm, glabrous outside. Stamens included, ± equal; filaments sparsely pubescent basally; anthers ellipsoid-sagittate. Ovary glabrous. Capsule globose or ovoid, papery. Seeds blackish, 3-4 mm, glabrous, apex acute. Fl. and fr. year round.

Sandy fields near the coast, cultivated areas, wasteland, roadsides, forest openings; 0-300 m. Guangdong, Guangxi, Hainan, Taiwan, Yunnan [?Bangladesh, Cambodia, India, Indonesia, Laos, Malaysia, Myanmar, New Guinea, Philippines, Singapore, Sri Lanka, Thailand, Vietnam; Africa, N Australia].