四瓣马齿苋 si ban ma chi xian

Portulaca formosana (Hayata) Hayata; P. quadrifida var. formosana Hayata.

Herbs annual. Stems articulated, prostrate, rooting at nodes; leaf axils patent pilose. Leaves opposite; petiole absent; leaf blade flat, ovate, obovate, or ovate-elliptic, 4-8 × 2-5 mm, slightly narrowed toward base, apex obtuse or acute. Flowers solitary, surrounded by involucre of 4 or 5 bracts, white pilose. Sepals obovate-oblong, 2.5-3 mm, membranous, veined. Petals 4, yellow, oblong or broadly elliptic, 3-6 mm, connate at base, apex mucronate. Stamens 8-10. Ovary ovoid. Stigma (3- or)4-lobed. Capsule globose, ca. 2.5 mm, pericarp membranous. Seeds gray, subglobose, laterally compressed, minute, muricate. Fl. and fr. year-round.

Open disturbed grounds, sandy soils. Guangdong, Hainan (including Xisha Qundao), Taiwan, S Yunnan [probably native to Africa, now pantropical].

The plants are used for medicinal purposes. They are sometimes a troublesome weed of cultivation, as they break up very easily and small fragments can act as propagules.