6. Oxalis acetosella Linnaeus, Sp. Pl. 1: 433. 1753.
白花酢浆草 bai hua cu jiang cao
Perennials 8-15 cm tall, stemless. Rhizome creeping under-ground, slender, mostly covered with fleshy pale brown scalelike remains of leaf bases, ca. 1 mm thick not including scales, ca. 3 mm thick including scales; scales pale brown, sparsely strigose. Petiole 3-15 cm; leaflet blades obcordate, 0.5-2 × 0.8-3 cm, apex deeply emarginate; lobe apices rounded. Flowers solitary, nodding; peduncle as long as or longer than leaves; bracts at middle of flowering stalk, lanceolate, ca. 3 mm, with trichomes around apex. Sepals ovate-lanceolate, persistent. Petals white, lilac to pinkish veined, obovate, (1.2-)1.5-2.2 cm, apex retuse to deeply emarginate. Capsule angular-ovoid, 3-4 mm. Seeds light brown, ovoid, longitudinally ridged. Fl. Jul-Aug, fr. Aug-Sep. 2n = 22.
Forests, shady places; 800-3700 m. Heilongjiang, Jilin, Liaoning, Ningxia (Liupan Shan), Xinjiang [Japan, Korea, Mongolia, Nepal, Pakistan, Russia; Europe].
This species is often misidentified, with robust forms attributable to Oxalis griffithii (which has a much thicker rhizome with dark brown scales and densely pubescent bracts) and slender forms attributable to O. leucolepis (which has thin rhizomes with widely spaced scales and glabrous, often rotund bracts). See Veldkamp (Fl. Males., Ser. 1, Spermat. 7(1). 1971) for discussions on O. acetosella sensu lato. Records from Zhongdian Xian and Lijiang Xian in Yunnan (X. Chuang, Fl. Yunnan. 5: 106. 1991) require confirmation.