Volume 14 > Part 3 > Year 2019 > Page 367 > Begoniaceae > Begonia

5. Begonia barbellata Ridl.wfo-0000823426

[§ Bracteibegonia], J. Fed. Malay States Mus. 10: 135. 1920; Ridl., Fl. Malay Penins. 1: 856. 1922; Irmscher, Mitt. Inst. Allg. Bot. Hamburg 8: 116. 1929; Kiew, Begonias Penins. Malaysia 129. 2005; Hughes, Annot. Checkl. SE Asian Begonia. 12. 2008.

Accepted Name : This is currently accepted.

Description : Monoecious caulescent herb with dense reddish brown bristles on all vegetative parts, 20−30 cm tall, creeping on forest floor. Stem base rhizomatous; rhizome elongate, creeping, densely hairy, 4−5 mm diam. Leaves alternate distichous; petiole 5−10 mm long, densely hairy; lamina basifixed, asymmetric, adaxial surface densely hairy, dull dark green, abaxial surface densely hairy especially on veins, obovate to oblong, 8−10 by 3−4 cm, base narrowly cuneate, oblique, apex caudate, margin serrate and hairy, venation pinnate, 7−8 pairs branching, slightly impressed above, prominent beneath with reddish hairs on veins. Stipules persistent, ovate, 4−5 by 3−4 mm, apex acute, margin entire, hairy. Inflorescences axillary, bisexual, ca 15 mm long, dichasial, branching 1–2 times, protandrous; peduncle 10−12 mm long, terete, hairy. Bracts persistent, membranous, lanceolate, 3−4 by 1−2 mm, glabrous, apex obtuse, margin entire. Staminate flowers: pedicels 8−10 mm long; tepals 4, outer 2 ovate to orbicular, densely hairy on outer parts, yellowish white, 9−10 by 9−11 mm, base rounded, apex rounded, margin entire, glabrous, inner 2 oblanceolate, 4−7 by 2 mm, base cuneate, apex obtuse, margin entire, glabrous; androecium actinomorphic, globose; stamens numerous, filaments fused at base ca 1 mm long, anthers oblong ca 1 mm long, dehiscing by lateral slits. Pistillate flowers: pedicels 5−8 mm long; tepals 5, unequal, hairy outside, outer 3 yellowish white, ovate, 7−10 by 6−8 mm, inner 2 yellowish white, ovate, 5 by 3 mm; styles 3, fused at base, 3 mm long, stigmatic band U-shaped; ovary with 3 equal narrow wings, 3-locular, placentae bilamellate. Fruit a dehiscent capsule, nodding, pendulous, drying pale brown, ca 20 by 10 mm; locules ovate, 15 by 5−6 mm, abaxial wing curved with rounded tip, 20 mm wide and 10 mm tall, two lateral wings similar. Seeds brown, barrel-shaped.

Thailand : PENINSULAR: Narathiwat.

Distribution : Peninsular Malaysia (type).

Ecology : On hill slopes in tropical rain forests, ca 100 m alt. Flowering: June; fruiting: November.

Vernacular : Dat bai khon (ดาดใบขน).

Notes: The epithet barbellata (Latin) refers to the short stiff hairs on all vegetative parts of the plant.