紫背天葵 zi bei tian kui

Begonia cyclophylla J. D. Hooker.

Herbs, deciduous. Tubers 7-8 mm in diam. Leaf solitary; stipules ovate-lanceolate, 3-7 × 2-4 mm, apex acute and cuspidate; petiole 3-11.5 cm, villous; blade broadly ovate, 6-13 × 4.8-8.5 cm, nearly symmetric, rugulose, abaxially hairy, adaxially sparsely pubescent, venation palmate, 7(or 8)-veined, base slightly oblique, cordate or deeply cordate, margin denticulate, apex acute or shortly acuminate. Inflorescences terminal, cymose, 6-18 cm tall, glabrous; bracts oblong, 3-4 × 1.5-2.5 mm, glabrous, apex obtuse or acute. Staminate flowers: pedicel 1.5-2 cm; tepals 4, pale pink to purplish pink, glabrous, outer 2 broadly ovate, 8-13 × 8-10 mm, inner 2 obovate-oblong, 7-12.5 × 4-5 mm; stamens 50-60; filaments 1-1.5 mm; anthers oblong or obovoid-oblong, 0.6-1 mm, apex emarginate or obtuse. Pistillate flowers: pedicel 1-1.5 cm; tepals 3, pale pink to purplish pink, glabrous, outer 2 oblate or orbicular, 6-8 × 9-11 mm, inner 1 oblanceolate, 6.1-9.2 × 2.8-4.2 mm; ovary 5-6 mm, glabrous, 3-loculed; placentae axile, bilamellate; styles 3, 2.8-3 mm, free or fused to halfway; stigmas U-shaped. Capsule pendulous, ovoid-oblong, ca. 11 × 7-8 mm, unequally 3-winged; abaxial wing triangular, 1.1-1.4 cm; lateral wings ca. 3 mm. Fl. May, fr. Jun. 2n = 22*.

● Forest understories, on rocks or on soil of slopes; 700-1100 m. Fujian, Guangdong, Guangxi, Hainan, Hunan, Jiangxi, Zhejiang.

The leaves of this species are harvested and dried for brewing a beverage (i.e., a tea) in Guangdong.