Volume 14 > Part 3 > Year 2019 > Page 385 > Begoniaceae > Begonia

18. Begonia handelii Irmsch.wfo-0000824214

[§ Platycentrum], Anz. Akad. Wiss. Wien, Math.–Naturwiss. Kl. 58: 24. 1921; Irmscher, Mitt. Inst. Allg. Hamburg 6(3): 348. 1927; Tebbitt, Edinburgh J. Bot. 60: 6. 2003; Hughes, Annot. Checkl. SE Asian Begonia. 48. 2008; Camfield & Hughes, Eur. J. Taxon. 396: 41. 2018. Fig. 10.

Accepted Name : This is currently accepted.

Synonyms & Citations :

Description : Dioecious caulescent herb, up to 40 cm tall. Stems rhizomatous at base; rhizome elongate, creeping, ca 10 mm diam, with numerous fibrous roots, aerial stem upright from rhizome, ca 1−10 cm long. Leaves: petiole 25−30 cm long, joining midrib at a distinct angle; lamina basifixed, succulent, asymmetric, coriaceous when dry, adaxial surface glabrous, abaxial surface with sparse glandular hairs on veins, ovate-lanceolate, 8−20 by 7−16 cm; base asymmetric cordate, apex acuminate, margin undulate, serrate with short angular lobes, venation palmate, 7−8 veins, slightly impressed above and prominent beneath. Stipules persistent, ovate-lanceolate, 10−20 by 4−10 mm, apex acute, margin entire, glabrous. Inflorescences arising from rhizome, unisexual, dichasial; peduncle dark red, short, 0.5–2 cm long in inflorescences of both staminate and pistillate flowers, terete, very hairy. Bracts persistent, membranaceous, ovate-lanceolate, 12−15 by 5−7 mm, apex acute, margin entire, glabrous. Staminate flowers: pedicels 3−10 cm long; tepals 4, pinkish white, outer 2 broadly ovate to elliptic, 20−50 by 10−20 mm, base rounded, apex acute, margin entire, glabrous, inner 2 obovate, 6−30 by 5−8 mm, base cuneate, apex obtuse, margin entire, glabrous; androecium actinomorphic, globose, stamens numerous, filaments slightly fused at base, 1–3 mm long, anthers oblong, 2−3 mm long, dehiscing by longitudinal slits on the sides, lobes more than half length of anther. Pistillate flowers: pedicels 15−70 mm long; tepals 4, pinkish white, outer 2 ovate to elliptic, 5−25 by 19−20 mm, base cuneate, apex obtuse, margin entire, glabrous on both sides, inner 2 ovate to elliptic, 3−15 by 6−15 mm, base cuneate, apex obtuse, margin entire, glabrous on both sides; styles 4, once spirally twisted, fused at base, stigmatic band crescent-shaped, spiral; ovary obovate with 4 short equal triangular wings, 4-locular, placentae bilamellate. Fruit a fleshy berry, 1−4 in infructescence, erect with glandular hairs when young, mature fruit glabrous, drying pale brown, 10−20 by 10−16 mm, 4 wings triangular, ca 2 mm long. Seeds barrel-shaped.

Thailand : NORTHERN: Chiang Mai, Chiang Rai, Tak.

Distribution : India, China (Yunnan), Laos, Vietnam (type), Myanmar.

Ecology : In granite rock crevices by streamsides in seasonally dry evergreen forests, 900−1,400 m alt. Flowering: Febuary; fruiting: June.

Vernacular : Kam kung hu chang (ก้ามกุ้งหูช้าง).

Notes: This widespread taxon is known from only 3 collections in Thailand, which is likely to be the southern most part of its range. Tebbitt (2003) identified the Thai specimens as Begonia handelii var. prostrata but here we treat the differences in the size and shape of the tepals as variation within the type variety.