Begonia bintang 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 : 5-6

2. Begonia bintang Rimi , spec. nov. ( Figure 3 )

Sect. Petermannia

This species belongs to the Begonia cauliflora group of begonias with narrowly obovate, almost symmetric, non-oblique leaves and short petioles, but it is different from other species in this group and indeed in all other begonias in having an extremely narrow fruit giving it the shape of a flying saucer and in the extremely short finger-like wings that radiate star-like from the locules.

Type:— MALAYSIA. Borneo. Sabah. Papar District: Crocker Range Park, Sub-station Ulu Kimanis , 24 June 2007, Kinahim et al. KNP 10553 (holotype SNP!; isotype SAN!) .

Erect herb 8–45 cm tall. Stem brown or red with long adpressed hairs, 1.5–3.5 mm thick, unbranched, internodes 0.4– 1.7 cm long. Stipules pale green, glabrous, lanceolate, 10 × 3–4 mm, margin entire, keeled, apex setose, seta to 1 mm long, persistent. Leaves alternate, not oblique, distant, held horizontally; petiole brownish green, with long adpressed hairs, 4–5 mm long, shallowly grooved above; lamina plain rice green above, paler or sometimes red below, fleshy in life, papery when dry, glabrous above, slightly glossy, narrowly obovate, symmetric, 6.5–12.5 × 2–3 cm, basal lobe not developed, in the lower three quarters margin entire, serrate in the upper quarter, apex attenuate to a narrow point; venation pinnate, veins concolorous, 3 on either side of the midrib, beneath with long adpressed hairs, impressed above, slightly prominent beneath. Inflorescences protogynous, axillary, with many along the stem, compact, simple cymes, ca. 4 mm long. Bracts brown, oval, ca. 2 × 1.8 mm, margin entire, caducous; bracteoles reddish, lanceolate, ca. 2 × 1 mm, margin entire, caducous. Female flower: pedicel ca. 0.5 mm long, greenish, sparsely hispid; ovary greenish white, turbinate, 4 × 7–14 mm, wings 3, equal, locules 3, placenta 2 per locule with many ovules on both surfaces; tepals 5, white sometimes pinkish, elliptic, glabrous, margin entire, apex acute, outermost 4 tepals ca. 9 × 7 mm, innermost tepals ca. 8 × 1 mm; styles 3, yellow, 3–4 mm long, divided to base; stigma yellow, papillose forming a continuous twisted band. Male flower: pedicel white, 5–12 mm long; tepals 4, margin entire, apex acute, oval, outer 2 tepals white or sometime pinkish, glabrous, 5–9 × 5–8 mm, inner 2 tepals 5–9 × 2–4 mm; stamen 21–26, cluster globose, sessile; filament yellow, ca. 1 mm long; anthers yellow, obovate, ca. 0.8 × 0.3 mm, apex emarginate. Capsule subsessile; fruit turbinate, 4–5 × 15–20 mm, green or white, hispid, wing equal, wing digitate (finger-like), ca. 2 mm long, ca. 5 mm wide, thinly fibrous, dehiscence. Seed: shape, ca. 0.2 × 0.1 mm, columnar cells more than half of seed length.

Distribution: — MALAYSIA. Borneo, Sabah, Paper District. Endemic in Crocker Range.

Habitat: —On rocks, on riverbanks in primary forest under shade, at 400 m elevation.

Etymology: — Bintang (Malay) means star and describes the unusual fruit that from above appears star-like with radiating arms.

Additional specimens examined: — MALAYSIA. Borneo. Sabah. Papar District: Crocker Range Park – Ulu Kimanis, Trail 2, Duni et al. KNP A 15395 (SNP, SAN); Ulu Kimanis, road to Maihang, Kinahim et al. KNP 10591 (SNP), Kinahim et al. KNP 10585 (SNP), Kinahim et al. KNP 10593 (SNP), Kinahim et al. KNP 10586 (SNP); Ulu Kimanis Substation, Kinahim et al. KNP 10573 (SNP); Membakut, Ulu Megindanau, Rimi et al. SP 17332 (SNP), Ulu Kimanis, Yabanus KNP 14293 (SNP), Yabanus KNP 14294 (SNP); Penampang District: Crocker Range Park – Inobong Substation, Kimbambangan trail, Lens FL 65 (SNP, SAN), Lens FL 66 (SNP).

Notes: —It is not clear how this unusually shaped fruit dehisces nor how the seeds are dispersed. It appears that the inflorescences are unisexual, but more observations from living material are necessary to confirm this.

Figures

FIGURE 3. Begonia bintang. A. Habit; B. Male flowers; C. Female flowers; D. Fruit. Photos A & B by Kinahim Sampang; photo C by Ramlan Miadin and photo D by Yabainus Juhalin.