87. Begonia longialata K. Y. Guan & D. K. Tian, Acta Bot. Yunnan. 22: 132. 2000.
长翅秋海棠 chang chi qiu hai tang
Herbs, glabrous throughout. Rhizomes elongate. Stems 30-50 cm tall, with many red, linear dots. Leaves basal and cauline; stipules 1.6-1.9 × 1.2-1.3 cm; petiole 13-31 cm, glabrous, with red linear spots; blade suborbicular, slightly asymmetric, 24-44 × 24-41 cm, venation palmate, 5-9-veined, base deeply cordate, margin irregularly serrulate, distinctly divided to 2/3 of leaf length; lobes 5-7, apex acuminate; lobules present. Inflorescence glabrous, 11-23-flowered; peduncle 5-10 cm, with red linear dots; bracts reddish, ovate, 1.8-2.5 cm. Staminate flowers: pedicel 2-5 mm; tepals 4, white to pink, glabrous, outer 2 suborbicular, 1.5-1.7 × 1.3-1.8 cm, inner 2 narrowly obovate, 10-17 × 8-10 mm; stamens ca. 160; filaments 3-5.5 mm; anthers obovoid, 1.3-1.7 mm. Pistillate flowers: pedicel 1.8-4.8 cm; tepals 5, white to pink, unequal, largest broadly obovate, 1.4-2.3 × 1.2-1.8 cm, smallest obovate to elliptic, 1.3-2.1 × 1-1.6 cm; ovary often brownish red, 2-loculed; placentae axile, bilamellate; styles 2(or 3), 4.2-4.8 mm, fused at base; stigmas 2-cleft, spiraled. Capsule nodding, obovoid, ca. 1.6 × 1 cm, unequally 3-winged; wings brownish red, abaxial wing 3-5 cm; lateral wings ca. 2 mm. Fl. Aug-Dec.
● Rocky slopes; ca. 900 m. SW Yunnan (Gengma).
This species resembles Begonia macrotoma but differs by its stem, petioles, and peduncle having conspicuous, red, linear dots and the much longer (3-5 cm) abaxial wing of the capsule.