Volume 14 > Part 3 > Year 2019 > Page 396 > Begoniaceae > Begonia

26. Begonia kingiana Irmsch.wfo-0000824465

[§ Ridleyella], Mitt. Inst. Allg. Bot. Hamburg 8: 106. 1929; Kiew, Begonias Penins. Malaysia 37. 2005; Hughes, Annot. Checkl. SE Asian Begonia. 65. 2008.

Accepted Name : This is currently accepted.

Description : Monoecious rhizomatous herb. Rhizome elongate, creeping, glabrous, ca 30 cm long, 4−5 mm diam. Leaves: petiole glabrous, ca 10 cm long; lamina peltate, succulent, asymmetric, chartaceous when dried, glabrous on both sides, ovate to oval, 8−10 by 8−10 cm, base obliquely rounded, apex caudate, margin entire or somewhat sparsely caudate 2−3 near the apex, venation palmate, 7−9 lateral veins branching, slightly impressed above and prominent beneath. Stipules persistent, ovate, 4−5 by 3−4 mm, apex acute, margin entire. Inflorescences arising from rhizome, bisexual, ca 15 cm long, polychasial, branching 1–2 times, protandrous; peduncle 10−12 cm long, terete. Bracts persistent, membranous, ovate, 3−4 by 1−2 mm, apex obtuse, margin entire, glabrous. Staminate flowers: pedicels 8−10 mm long; tepals 4, outer 2 ovate to orbicular, reddish, 4−5 by 4−6 mm, base rounded, apex rounded, margin entire, glabrous, inner 2 oblanceolate, 15 by 3 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 longitudinal slits. Pistillate flowers: pedicels 5−10 mm long; tepals 4, unequal, glabrous, outer 2 dark red,ovate, ca 4−5 by 5−6 mm, inner 2, white, oblanceolate, 5 by 2 mm; styles 3, fused at base, stigmatic band crescent-shaped, once spirally twisted; ovary with 3 unequal wings, 2-locular, placentae unilamellate. Fruit a dehiscent capsule, nodding, pendulous, drying pale brown, 20 by 10 mm; locules ovate, 15 by 5−6 mm, abaxial wing curve with rounded tip, 20 mm wide and 10 mm tall, lateral wings narrower, curved along length of capsule, 3−4 mm long. Seeds brown, barrel-shaped.

Thailand : PENINSULAR: Trang.

Distribution : Peninsular Malaysia (type).

Ecology : On granitic rocks in seasonally dry evergreen forests near waterfalls, ca 200 m alt. Flowering: June; fruiting: November.

Vernacular : Dat bai bua (ดาดใบบัว).

Notes: The peltate thickly succulent leaves are very characteristic. Previously reported as endemic to Peninsular Malaysia (Kiew, 2005) on limestone hills, but now known from Thailand from one specimen in Trang province. As this species can grow on granitic rocks it may be distributed further north in the Peninsula.