136. Begonia rongjiangensis T. C. Ku, Acta Phytotax. Sin. 33: 279. 1995.
榕江秋海棠 rong jiang qiu hai tang
Herbs, deciduous. Tubers globose, 5-8 mm in diam. Leaves basal, 2-5; stipules caducous; petiole 4-9.5 cm, glabrous; blade asymmetric, narrowly ovate, 8.5-11 × 5.5-9.5 cm, glabrous, venation palmate, 5-7-veined, base oblique, slightly cordate, margin shallowly serrate, sometimes biserrate, apex acuminate. Inflorescence 15-22 cm tall, glabrous; flowers red; pedicel 3-8(-10) mm, glabrous; bracts caducous, lanceolate, ca. 3 mm. Staminate flowers: tepals 4, outer 2 depressed-ovate, 6-8 × 6-7 mm, abaxially villous, inner 2 oblong, 6-8 × 1-2 mm; stamens numerous; filaments fused to ca. 1 mm at base; anthers oblong, 1-2 mm, apex emarginate. Pistillate flowers: tepals 2, broadly obovate, 7-8 × 6-7 mm, apex emarginate; ovary oblong, pilose, 3-winged; abaxial wing oblate-triangular, ca. 10 × 5 mm, apex acute; lateral wings smaller, lunate, 1-2 mm; styles 3; stigma globose. Fl. Aug.
● Slopes by streams. Guizhou (Rongjiang).
This species is similar to Begonia labordei but can be distinguished by the 2-tepaled pistillate flowers.