Begonia segerakensis C.Y.Ling & Kiew, 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 : 27-30

11. Begonia segerakensis C.Y.Ling & Kiew , sp. nov.

Similar to Begonia jenginensis S.Julia & Kiew in its habit, large hairy leaves with long petioles, and male flowers with 4 tepals but differs in its conspicuously hispid petioles (versus minutely pubescent petioles); lower lamina surface sprinkled with bristles (versus lower surface glabrous between the veins); dichasium 2–3 cm long (versus racemose inflorescence, usually 10–15 cm long); smaller ovate bracts, 4–6 × 2–3 mm (versus lanceolate, 12–17 × 4–5 mm); smaller bracteoles, 3–5 × 2–5 mm, with glandular knobs on the margin (versus non-glandular bracteoles, 4–10 × c. 4 mm); male flowers with broadly ovate outer tepals 6–7 × 7–8 mm, outer surface densely covered by red bristles (versus outer tepals ovate, glabrous, 8–10 × 5–8 mm); female flower with shorter pedicel, c. 1.5 mm long (versus pedicel 4–8 mm long); ovary, particularly the locules, covered in red bristles (versus ovary glabrous); and capsules single, 8–10 mm long (versus 2–4 capsules along the rachis, each 12–14 mm long) with shorter pedicel to c. 2 mm long (versus 6–15 mm long).

– Type: Malaysia, Borneo, Sarawak, Lubok Antu District , Lanjak Entimau Wildlife Sanctuary , Nanga Segerak , Along Segerak trail, 1°23′51′′N, 112°01′39′′E, 21 x 2016, Ling et al. SFC 7064 (holotype SAR !, isotype KEP!). Figure 12 .

Cane-like herb, when young lax and occasionally appearing creeping when the stem base roots at ground level, when mature erect to 1 m tall. Stem, stipule, petiole and both leaf surfaces with hispid hairs to 7 mm long, whitish or reddish. Stems unbranched, brownish to green brown or red brown, internodes (1.5–) 3–7.5 cm long, 4–6 mm thick, slightly thicker at nodes. Stipules greenish or reddish, tinged red on the keel, ovate, 10–18 × 6–8 mm, margin entire, keeled, apex setose, seta to 5 mm long, caducous. Leaves distant, alternate, oblique; petioles reddish or red brown, 4.5–10 cm long, succulent, terete or slightly grooved above, held more or less horizontally; lamina hispid, plain green above, paler beneath, in life succulent, shiny, asymmetrical, ovate, 10–14.5 × 6.5–12 cm, broad side 5–8 cm wide, base cordate, overlapping, unequal, basal lobe 5.5–8.5 cm long, margin minutely dentate and ciliate, apex acuminate, acumen 1–2 cm long; venation palmate-pinnate, veins greenish above except reddish at base, paler green beneath, prominent on both surfaces, 2 or 3 veins radiating from the base, branching 2 or 3 times towards the margin, 5 or 6 veins in basal lobe, 2 or 3 on either side of the midrib. Inflorescences protogynous, in upper leaf axils, simple dichasium 2–3 cm long, peduncle reddish; bracts reddish, ovate, 4–6 × 2–3 mm, margin entire, keeled, apex setose, seta c. 1 mm long, caducous; bracteoles pale green tinged red at base, ovate, 3–5 × 2–5 mm, margin with prominent glandular knobs, apex rounded to emarginate, persistent. Male flowers: pedicel pinkish, 8–10 mm long; tepals

4, outer two tepals white and glabrous inside, tinged pink, outside densely covered by red bristles, margin entire, apex acute, broadly ovate, 6–7 × 7–8 mm, inner two tepals white, glabrous, margin entire, apex acute lanceolate, 4–6.5 × 2–2.5 mm; stamens c.35, cluster loosely globose, subsessile, filaments c. 1 mm long; anthers yellow, obovate, c.1 × 0.5 mm, apex emarginate. Female flowers: pedicel pale green, glabrous, c. 1.5 mm long, ovary pale green, hispid, bristles red, particularly dense on the locules, wings 3, unequal, ovate, ovary including the wings c.7 × 16 mm, locules 3, placentas 2 per locule; tepals 5, white tinged pink at base; outer three tepals ovate, c.9 × 9 mm, sparsely hairy outside, margin entire, apex acute, inner two tepals narrowly ovate, c.8 × 4 mm, glabrous, margin entire, apex acute; styles 3, yellow green, 2–2.5 mm long; stigma yellow, anchor-shaped, papillose. Capsules single, ovate, 8–10 × 14–16 mm, locules 3, hairy outside, wings 3, unequal, 3–5 mm wide, rounded proximally, rounded to truncate distally, dehiscing between the locules and wings; pedicel pendent, c. 2 mm long.

Distribution. Malaysia ( Sarawak). To date, known only from Nanga Segerak in Lanjak Entimau Wildlife Sanctuary (see Figure 1 ).

Habitat. On steep slopes below the ridge in mixed dipterocarp forest occasionally with sandstone boulders, at elevations to 925 m.

Etymology. Named after the locality, Nanga Segerak, where the species was discovered.

When sterile, Begonia segerakensis can easily be confused with B. jenginensis , but it differs in its hairy lower lamina surface, flowers and fruits (see diagnosis above).

Figures

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

Figure 12. Begonia segerakensis C.Y.Ling & Kiew, sp. nov. A, Habit; B, stipule; C, upper leaf surface; D, lower leaf surface; E, inflorescence; F, bracteoles; G, male flower; H and I, female flower; J, dry capsule; K, cross-section of female flower. All photographs of the type specimen, Ling et al. SFC 7064, taken by C. Y. Ling.