B. abbreviata

Herbs perennial, monoecious. Rhizomes green or reddish, terete, 6–8 mm across, to 10 cm or longer, creeping, appressed reddish pubescent, internodes1–4 cm long. Stipules triangular, 1.3–1.8 cm long, ca. 7 mm wide, puberulent, apex acuminate and cuspidate, cusp 3 mm long, margin entire. Leaves alternate; petiole 2–5 cm long, 3–4 mm across, appressed pubescent; leaf blade ovate to broadly ovate, apex acute to mucronulate, base obliquely cordate, margin entire, 6–17 cm long, 5–12 cm wide; adaxially green or with many silver white patches in intercostal regions; patches elliptic, to 8 mm long, 5 mm wide, minutely puberulent; abaxially reddish tomentulose on red veins and veinlets; primary veins palmate, dichotomous, veinlets reticulate. Inflorescence unisexual or bisexual, in cymosely branching panicle, protogynous, axillary and terminal on the rhizome, erect, reddish, subglabrous, peduncles 0.5–1.5 cm long; female inflorescence 1–3-flowered, male inflorescence single or branched, flowers 5–30. Flowers scented. Bracts reddish, persistent, narrowly ovate at base of inflorescence, ca. 13–18 mm long,6 mm wide, apex acute, margin ciliate; widely ovate at summit of inflorescence (with staminate flowers), 6–8 mm long, ca. 6 mm wide, margin ciliate. Staminate flower: pedicel 2.5–3 cm long, tepals 4, outer 2 white or pinkish, with apparent red veins, orbicular to ovate, 1.2–1.5 cm long, 1–1.2 cm wide, margin entire, abaxially sparsely reddish-scabrescent or subglabrous; inner 2 white or pinkish, oblanceolate, apex round, base cuneate, 0.9–1.2 cm long, ca. 3 mm wide, glabrous; androecium actinomorphic, stamens 40–52, yellow, filaments free, ca. 0.7 mm long, anthers ca. 1 mm long. Carpellate flower: pedicel 0.5–1 cm long, tepals 5, white or pinkish, with apparent red veins, suborbicular to narrowly oblanceolate, outer 3 suborbicular to broadly obovate, ca. 1 cm long, 0.7–1 cm wide, abaxially sparsely reddish-scabrescent; inner 2 unequal, obovate to narrowly so, ca. 1 cm long, 3–6 mm wide, glabrous; ovary trigonous-ellipsoid, sparsely reddish hirsute, 3-locular, 3-winged, wings subequal, ca.5 mm tall, placentation axile; styles 3, ca. 5 mm long, each forked at middle, stigmatic band spiralled. Capsule trigonous-ellipsoid, 0.9–1.6 cm long, 5–8 mm across, wings trapeziform with rounded tips and entire margin, 5–7 mm tall. Begonia abbreviata appears to be allied to B. eberhardtii Gagnepain (1919: 198), which was known only from a single collection made about a century ago from Vietnam. Both species are members of sect. Petermannia with elongate rhizomes and lacking upright stems. However, they differ markedly in leaf shape. In B. abbreviata, leaves are broadly ovate with entire margin and an acute apex. By contrast, leaves of B. eberhardtii are ovate, with irregularly and coarsely dentate margin and an acuminate apex. The specific epithet refers to the short peduncle in the new species.
Pests Diseases

• Classification: Species
• Plant Type: Rhizomatous
• Botanical Section: Petermannia
• Origin: Asia, Vietnam
• Originator: Ching-I Peng
• Date of Origin: 2015