Begonia bekakapensis C.Y.Ling & S.Julia, 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 : 6-8

2. Begonia bekakapensis C.Y.Ling & S.Julia , sp. nov.

Similar to Begonia umbratica S.Julia in its large stipules, large oblique ovate leaves and clustering inflorescences but differentiated by its monopodial stem to 40 cm tall (versus bushy branched stem to 1 m tall); much shorter petioles, 1.5–4 cm (versus 5–16 cm long); shorter peduncle, 7–8 mm (versus c. 15 mm long); longer pedicels of male flowers, 10–12 mm (versus 6–7 mm long); and female flowers with exceptionally large tepals, 10–19 × 8–10 mm (versus 8–10 × 6–8 mm).

– Type: Malaysia, Borneo , Sarawak, Kapit District , Baleh , Sungai Bekakap, 1°21′58′′N, 113°43′33′′E, 7 iii 2016, Ling et al. SFC 5904 (holotype SAR!, isotype KEP!). Figure 3 .

Erect monopodial cane-like herb to 40 cm tall. Stems reddish brown, occasionally with a short lateral branch, succulent, internodes 4–11 cm long, 5.5–9 mm thick, thicker at nodes. Stipules reddish, lanceolate, 3–4 × 0.8–1.2 cm, margin entire, apex acute, caducous. Leaves alternate, distant, oblique, held horizontally; petioles reddish brown, 1.5–4 cm long, grooved above; lamina glabrous, plain green above, dark green when older, with an iridescent silvery sheen, pale green sometimes magenta beneath, in life succulent, matt, asymmetrical, elliptic, 12.3–21.5 × 9–14.3 cm, broad side 6.5–10 cm wide, base cordate, basal lobe 3–4 cm long, margin slightly serrate, apex acuminate, acumen 1–2.5 cm long; venation palmate-pinnate, veins greenish above reddish near the leaf base, reddish beneath, with 4 or 5 veins radiating from the base, branching 2 or 3 times towards the margin, c.3 veins on each side of the midrib and 2 or 3 veins in basal lobe, slightly impressed above, prominent beneath. Inflorescences protogynous, axillary in upper leaf axils, clustered, 2–5 cm long, peduncle 7–8 mm long, 1 or 2 female flowers below, male flowers in compact cymules above; bracts pale green, red at base, lanceolate, 26–32 × 9–13 mm, margin entire, persistent; bracteoles pale green, ovate, 15–22 × 14–16 mm, persistent. Male flowers: pedicel pale green, 10–12 mm long, glabrous; tepals 2, white to pale green, reddish towards the base inside, outside white, glabrous, margin entire, apex broadly rounded, ovate, 6–8.5 × 6.5–7 mm; stamens 45–56, cluster conical, subsessile; filaments pale yellow, 0.8–1 mm long; anthers pale yellow, obovate, c.1 × 0.5 mm, apex emarginate. Female flowers: pedicel pale green, pink at base, 4–5 mm long, glabrous; ovary deep red to dark maroon with pale green centre, sometimes pale green with pinkish maroon wings, ovary including the wings oblong, 18–20 × 9–13 mm, glabrous, wings 3, equal, locules 3, placentas 2 per locule; tepals 5, white to pale green with reddish stripes, more prominent towards the base, glabrous, outer four tepals ovate or broadly elliptic, 10–19 × 8–10 mm, margin entire to minutely serrate, apex acute, inner tepal elliptic, 7–13 × 5–7 mm; styles 3, yellow, c. 2 mm long, deeply divided to base; stigma yellow, papillose forming a twisted band. Capsules pale greenish to dark maroon, 3–4.5 × 1.8–2.1 cm, glabrous, locules 3, placentas 2, wings 3, equal, rounded proximally, truncate distally, wings equal 7–9 mm wide, thinly fibrous, dehiscing between locule and wing; pedicel pendent, 11–13 mm long.

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

Habitat. Hill mixed dipterocarp forest growing near a small stream and seasonal creek in shade, and on forest margins exposed by logging activities at elevations to 684 m.

Etymology. Named after the type locality, Sungai Bekakap, from where the species was first collected.

An attractive species with relatively large flowers and in life with striking red fruits. The fruits of Begonia bekakapensis are similar to those of B. magnicarpa C.W.Lin & C.I Peng , but its inflorescence is much more compact and shorter than that of B. magnicarpa , which has cymosely branching panicles 17–26 cm long.

Figures

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

Figure 3. Begonia bekakapensis C.Y.Ling & S.Julia, sp. nov. A, Habit; B, stipule; C, male flowers; D, female inflorescence; E, female flower; F, capsules; G, cross-section of capsule. All photographs of the type specimen, Ling et al. SFC 5904, taken by C. Y. Ling.