Begonia saxifragoides

Monoecious rhizomatous herb. Rhizome stout, greyish-red to reddish-brown, 10 − 15 cm or longer, 8 − 12 mm thick, internodes congested, densely pilose or villous. Stipules persistent, reddish-brown, triangular, ca. 5 × 6 mm, herbaceous, strongly keeled, midrib scattered with hirsute, margin entire, apex aristate, arista 2.5 – 5 mm long. Leaves alternate, petiole terete, greyish-red to pale brownish-red, 9 − 13 cm long, 3.5 − 4.5 mm diameter, densely rosy pink to white pilose or villous, turning pale brown with age; leaf blade asymmetric, oblique, orbicular to reniform, 6.5 − 8.3 × 6.7 – 9 cm, broadside 3.6 – 5.4 cm wide, basal lobes cordate, 1.5 – 2.2 cm long, apex rounded, margin denticulate to crenulate, recurved and undulated, with a line of magenta to white pilose or puberulous hairs; leaf thinly coriaceous, succulent, adaxially glabrous or subglabrous, greyish-green to olive green, venation blackish-green and slightly impressed; abaxially pale reddish-green to magenta; venation basally ca. eight palmate, primary veins branching dichotomously or nearly so, tertiary veins reticulate; all veins densely pink to magenta pilose or puberulous on abaxial surface. Inflorescences axillary, bisexual, cymose arising directly from the rhizome, ca. two orders of branching; peduncle pink to red, 5.5 − 7 cm long, pinkish-white pilose or villous. Bracts caducous, yellowish-green to pinkish-green, at basal node of inflorescence ovate, ca. 6.5 × 3 mm, abaxially sparsely pilose or glabrous, margin fimbriate; bracts on upper nodes similar but gradually smaller. Staminate flower: pedicel pinkish-yellow to pale pinkish-green, 8 − 10 mm long, sparsely pilose, tepals 4, pinkish-white to pink, outer two suborbicular to widely obovate, 8.5 − 13 × 10 − 15 mm, abaxially pilose or villous, margin entire, apex rounded, inner two narrowly obovate to oblong, 8 − 10 × 4 − 5 mm, glabrous, apex obtuse or rounded; androecium zygomorphic, 3.5 − 5 mm across; stamens yellow, 40 − 45; filaments ca. 1.3 mm long, fused at base; anthers oblong to obovate, ca. 1 mm long, 2 - locular, apex retuse. Pistillate flower: pedicel pinkish-white to pale pinkish-green, 6 − 8 mm long, very sparsely pilose or glandular hairs, tepals 3, whitish-pink; outer two suborbicular to very widely obovate, 8.5 − 9 × 10 − 12 mm, abaxially pilose or puberulous, margin entire, apex rounded, inner one oblanceolate to narrowly elliptic, ca. 7.5 × 3 mm, apex obtuse; ovary widely trigonous-globose, 2.5 – 4 mm long, 3 – 4.5 mm thick (wings excluded), rosy pink to pale pinkish-yellow, sparsely pilose or glandular hairs; 3 - winged, wings unequal, pinkish-white to yellowish-pink, sparsely pilose or glandular hairs, margin entire; wings triangular to falcate, 3.5 – 4.5 mm long, lateral wings narrower, 1.5 – 2 mm wide, abaxial wing 3 – 4 mm wide; ovary 3 - locular, placentae bilamellate; styles 3, C-shaped, shortly fused at base, golden yellow, ca. 3.5 mm long, stigma slightly spirally twisted. Capsule body trigonous-globose, 6 – 7 mm long, 8 – 9.5 mm thick (wings excluded), yellowish-red to reddish-green when fresh; wings unequal, ca. 10 mm long, lateral wings triangular, 3 – 4 mm wide, abaxial wing triangular to falcate, 8 – 9 mm wide, truncate distally, rounded proximally.