Begonia flammea Rimi, 2015

Repin, Rimi, Sang, Julia, Kiew, Ruth & Mujih, Handry, 2015, Eleven new species of Begonia (Begoniaceae) from the Crocker Range, Sabah, Malaysia, Phytotaxa 208 (1), pp. 1-20 : 11-12

6. Begonia flammea Rimi , spec. nov. ( Figure 7 )

Sect. Petermannia

Similar to Begonia cauliflora in its narrowly obovate, almost symmetric, non-oblique leaves and short petioles, it differs in its orange-red, flame-coloured flowers (not pale pink as in B. cauliflora ) and larger flowers, the male tepals are 18–23 mm long (not ca. 8 mm long), narrow female tepals 12–19 × 2–4 mm (not 9–14 × 5–7 mm), and larger capsules 19–20 × 17–23 mm with toothed wings (not ca. 12 mm wide with wings with an entire margin).

Type:— MALAYSIA. Borneo. Sabah. Ranau District: MALAYSIA. Borneo. Sabah. Kinabalu Park, 26 June 2007, Rimi et al. KNP 10558 (holotype SNP!; isotype SAN!) .

Erect begonia 50–100 cm tall. Stem little- to much-branched, dark brown, red brown towards the apex, ca. 6 mm thick, slightly thicker at nodes, hispid, hairs brown 8–9 mm long, internodes 1.2–5.5 cm long. Stipules pale green, hispid, hairs brown, lanceolate, 6–11 × 3–4 mm, margin entire with rows of brownish hairs below, apex setose, seta ca. 2 mm long, persistent. Leaves alternate, not oblique, distant, held more or less straight; petiole slightly grooved above, reddish brown, hispid, hairs brown, 6–10 mm long; lamina plain green, paler below, slightly fleshy when fresh, glossy, with bristles between the veins on upper surface, lanceolate, sometimes slightly falcate, slightly asymmetric, 13.8–25.5 × 2–6.1 cm, broad side 1.4–3.8 cm wide, base attenuate, basal lobes 0.2–0.5 cm wide, margin doubly toothed with major teeth at the vein endings, upper half of the leaf attenuate to a narrow point; venation pinnate, veins concolorous, with 6 veins on each side of the midrib, 2 veins in basal lobe, impressed above, prominent beneath, bristly on the midrib and veins below. Inflorescences protogynous with single female flower at the base of male inflorescence, axillary on the lower part of the sometimes leafless stem, male inflorescence a simple cyme 4–7 mm long. Bracts pale green, lanceolate, ca. 8 × 0.2 mm, margin entire, persistent; bracteoles pale pink, lanceolate, ca. 0.3 × 0.1 mm, persistent. Female flower: pedicel ca. 4 mm long, pale orange-red, sparsely hairy; ovary pale orange, broadly ovate, ca. 8 × 10 mm, wings 3, equal, locules 3, placenta bilamellate with many ovules on both surfaces; tepals 5, sparsely hairy outside, outermost 4 tepals pale orange-red, lanceolate, ca. 19 × 4 mm, innermost tepal ca. 12 × 2 mm, margin entire, apex attenuate to a long point, sparsely hairy at the base of the lower tepal surface; styles 3, dirty yellow, 2–3 mm long, divided near the base, Y-shaped with twisted tips; stigma orange, papillose forming a continuous twisted band. Male flower: pedicel pale orange-red, 5–8 mm long; tepals 2, orange, glabrous above, sparsely hairy towards base, broadly lanceolate, 1.8–2.3 × 0.6–1.1 cm, margin entire, apex narrowly acute; stamens 30, cluster conical, stalk ca. 0.4 mm long; filaments pale yellow, 2–3 mm long; anthers dirty yellow, obovate, 0.6–0.8 × 0.3 mm, apex emarginate. Capsule on pendent pedicel 5–6 mm long; fruit 1.9–2 × 1.7–2.3 cm, hispid, locules 3, wing equal, deltoid with a toothed margin, 7–8 mm wide, thinly fibrous, dehiscing between locule and wing. Seed: oblong, ca. 0.3 × 0.1 mm, columnar cells more than half the length of seed.

Distribution: — MALAYSIA. Borneo. Endemic in Sabah.

Habitat: —Lower montane, to 450 m elevation, on riverbank.

Etymology: — Flammeus (flame-coloured) refers to the striking flower colour. Most Bornean begonias have pale pink or white flowers.

Additional specimens examined: — MALAYSIA. Borneo. Sabah. Ranau District – Cultivated in Poring Hot Spring Nursery originally collected from Kinabalu Park, Langanan Waterfall, Rimi et al. SNP 36808 (SNP); Penampang District – Crocker Range Park, Sub-station Inobong, Rimi et al. KNP 10547 (SNP).

Figures

FIGURE 7. Begonia flammea. A. Habit; B. Hairy stems; C. Cymose male flower; D. Open male flowers; E. Female flower; F. Old fruit. Photo A from SNP 24836 by Yabainus Juhalin; photos B–F from SNP 36808 by Julia Sang.