3. Oxalis pes-caprae Linnaeus, Sp. Pl. 1: 434. 1753.
黄花酢浆草 huang hua cu jiang cao
Oxalis cernua Thunberg.
Perennials, 5-15(-40) cm tall, acaulescent, sparsely pubescent; bulb with white fleshy contractile root and a slender vertical stem rising to soil surface; underground stem and soil surface crown bearing numerous small bulbils and scales. Petiole 3-10 cm, erect to spreading; leaflet blades obcordate, 0.8-2 × 1.2-3.2 cm, slightly succulent, bright green often with dark purple spots, glabrous, apex deeply emarginate. Umbellate cymes with 3-20 flowers; peduncle 2 × as long as petioles. Flowers 2-3 cm across, nodding. Sepals lanceolate, 2.5-4 × ca. 1 mm, apex with a pair of orange calli. Petals deep golden yellow, obovate. Capsule long terete, pubescent, very rarely formed. Fl. Apr-Sep.
Cultivated grounds, open habitats; low elevations. Naturalized at least in Fujian but cultivated elsewhere in S China and very likely to escape and spread vegetatively [native to South Africa].
This species is cultivated as an ornamental in at least Hubei, Shaanxi, and Xinjiang. It is widely introduced and a problem weed in the Mediterranean and warm temperate and subtropical areas.