Begonia kumangiana S.Julia & C.Y.Ling, 2022

Julia, S., Kiew, R. & Ling, C. Y., 2022, ADDITIONS TO THE BEGONIA FLORA OF SARAWAK, BORNEO, I: TWELVE NEW SPECIES AND A NEW RECORD, Edinburgh Journal of Botany 79 (410), pp. 1-46 : 18-20

7. Begonia kumangiana S.Julia & C.Y.Ling , sp. nov.

Similar to Begonia bosuangiana S.Julia in its creeping habit, indumentum and rounded leaves sprinkled with stiff hairs, but it differs in its larger stipules, 10–15 × 7–12 mm (versus c.6 × 4 mm); inflorescences with larger persistent bracts, 12–15 × 11–14 mm (versus caducous, c.3 × 2 mm) and persistent bracteoles, 4–7 × 6–10 mm (versus caducous, 1–2.5 × 1–2 mm); smaller outer male tepals, 5.5–7 × 3–4 mm (versus c.9 ×

5 mm); and larger female tepals, 4–5 × 2.5–3 mm (versus c.3 × 2 mm).

– Type: Malaysia, Borneo , Sarawak, Kapit District , Baleh, Sungai Bekakap, 1°21′58′N, 113°43′33′′E, 8 iii 2016, Ling et al. SFC 5905 (holotype SAR!, isotype KEP!). Figure 8 .

Creeping herb rooting at nodes, prostrate stem to c. 3 cm long, erect apex c. 2 cm tall. Stems, stipules and petioles hirsute, hairs whitish, 2–3 mm long, more prominent on petioles and young shoots. Stems pale green to brown, unbranched, succulent, 3.5–4 mm thick, internodes 1.2–2 cm long, slightly thicker at nodes. Stipules pale green, ovate to oblanceolate, 10–15 × 7–12 mm, margin ciliate, apex acute, persistent. Leaves alternate, distant, scarcely oblique; petioles red brown to pale green, 1.3–3(–5) cm long, terete; lamina plain green above, paler beneath, in life succulent, glossy, with sparse stiff hairs above, hairs whitish, glabrous beneath, slightly asymmetrical, young leaves almost symmetrical, sometimes with bluish sheen, broadly ovate, 4.8–6.6 × 5.3–6.9 cm, broad side 3.1–4.3 cm wide, base cordate, occasionally overlapping, basal lobes 6–8 mm long, margin minutely serrate, fringed by sparse stiff hairs, apex broadly acute to rounded; venation palmate, veins greenish beneath, 4–6 veins on either side of the midrib, 1 vein in basal lobe, slightly impressed with sparsely stiff whitish hairs above, prominent and densely covered with minute white hairs beneath. Inflorescences protogynous, in upper leaf axils, held at a horizontal angle to the stem, racemose, 4–7 cm long, peduncle 2.2–4 cm long; bracts pale green, similar to stipules, ovate, 12–15 × 11–14 mm, margin ciliate, glabrous, persistent; lower bracteole similar to bracts (sometimes absent), ovate, c.7 × 5 mm, upper bracteoles 2–6 pairs, broadly ovate, 4–7 × 6–10 mm. Male flowers: pedicel white, 9–11 mm long, glabrous; tepals 4, outer two tepals white to deep pink, glabrous, ovate to elliptic, 5.5–7 × 3–4 mm, margin entire, apex broadly acute to rounded, inner two tepals lanceolate, 5–6.5 × 1.5 mm, margin entire, apex acute to rounded; stamens 10 or 11, cluster globose, subsessile; filaments yellow, 1.8–2 mm long; anthers yellow, obovate, c.2 × 2 mm long, apex emarginate. Female flowers: sessile; ovary greenish white, pink at the side of wings, ovate, ovary including the wings, 3–5 × 3–6 mm, glabrous, wings 3, subequal, locules 3, placentas 2 per locule; tepals 5, outer four tepals pinkish, glabrous, ovate or broadly elliptic, 4–5 × 2.5–3 mm, margin entire, apex acute, inner tepal narrowly elliptic, 4.5–5 × 1.5 mm; styles 3, yellow, c. 2.5 mm long, divided to base, anchor-shaped; stigma pale yellow, papillose forming a twisted band. Capsules not seen.

Distribution. Malaysia ( Sarawak). To date, known only from Sungai Bekakap in Kapit District (see Figure 1 ).

Habitat. Locally common in steep hill forest on slightly mossy sandstone boulders, above a seasonal creek, at elevations to 684 m. It creeps vertically up small, mossy sandstone boulders. Its leaves are held vertically against the substrate, and the inflorescences are held perpendicularly to the stem.

Etymology. Kumang is the name of one of the mystical people in Iban (Sea Dayak) culture, who is believed to be pretty and knowledgeable, and an appropriate inspiration for the name of this pretty, dainty begonia.

Begonia kumangiana is uncommon in its known locality. In its habit and leaf characters, it resembles Begonia addrinii but can be distinguished from that species by its conspicuously larger bracts (12–15 × 11–14 mm versus 4–7 × 2–3 mm) and bracteoles (4–7 × 5–10 mm versus 4–9 × 2–4 mm). This species co-occurs with Begonia bekakapensis .

Figures

Figure 1. Distribution of Begonia papyraptera and the 12 new species of Begonia recorded from Sarawak and described in this article.

Figure 8. Begonia kumangiana S.Julia & C.Y.Ling, sp. nov. A, Habitat; B, habit; C, stipule; D, upper surface of lamina; E, inflorescence; F and G, male flower; H and I, female flower; J, cross-section of ovary. All photographs of the type specimen, Ling et al. SFC 5905, taken by C. Y. Ling.