Begonia vulgare S.Julia & Kiew, 2013

Sang, Julia, Kiew, Ruth & Geri, Connie, 2013, Revision of Begonia (Begoniaceae) from the Melinau Limestone in Gunung Mulu National Park and Gunung Buda National Park, Sarawak, Borneo, including thirteen new species, Phytotaxa 99 (1), pp. 1-34 : 26-28

12. Begonia vulgare S.Julia & Kiew , spec. nov. ( Figure 15 )

Sect. Petermannia

It most resembles Begonia meriraiensis S.Julia & Kiew (2009: 357) , but it is different from this species in its more or less glabrous stem and petiole (compared with the dense long hairs (to 3 mm long) in B. meriraiensis ), much longer fruits 35–45 × 17–27 mm (not 20–28 × 14–20 mm). In addition, the leaves are somewhat smaller 13.5–18 × 6.5–12.5 cm (not 14–25.5 × 8–15 cm), and the female tepals narrower 6–10 × 5–7 mm (not 9–12 × 7–9 mm) and the venation more lax on the broader side.

Type: — MALAYSIA. Borneo. Sarawak. Marudi District: Gunung Mulu National Park, Deer Cave , 2 Oct 2007, Julia et al. S 99208 (holotype SAR!, isotypes E!, K!, KEP!, L!, SAR!, SING!) .

Bushy cane-like begonia to 2 m tall, much branched. Stems dark brown reddish towards the apex or green, slightly bristly, 2–4 mm diameter when dried, internodes 3–7 cm long. Stipules pale green or pale yellow, glabrous, with a distinct midrib, narrowly lanceolate, 18–35 × 4–6 mm, margin entire, apex narrowly, caducous leaving a circular scar. Leaves alternate, distant, young leaves bronzy or pale green with a red margin. Petioles dark red or rosy red, with scattered hairs, 5–15(–35) mm, grooved above. Laminas matt, dull green or yellowish green or sometimes bronzy above, paler beneath, with very sparse stiff short hairs on both surfaces, thinly papery when dried, slightly oblique, narrowly ovate, 13.5–18 × 6.5–12.5 cm, asymmetric, broad side 4–6.5 cm, on the narrow side base cuneate and on broader side rounded, basal lobe 1–1.5 cm, margin minutely dentate, apex acuminate, acumen to 0.5–1.5 cm long. Venation pinnate, lateral veins pairs with 2 pairs at the base and a further 4 ‘displaced’ pairs along the midrib, plus 2 veins in the basal lobe, branching 2–3 times before reaching the margin, impressed above, beneath prominent and hairy. Inflorescences axillary, red, erect and longer than petioles, racemose, protogynous, 9–19 cm long, peduncle rosy red or greenish brown (1–) 3.5–4.5 cm long, with one female flower and many male flowers on short branches 4–7 mm long from a spike 4.5–7(–14.5) cm long above. Bract pair bright green, elliptic, 13–20 × 4– 7 mm, persistent. Uppermost bracts of male flower bright green with a distinct midrib, pale green, elliptic, 7– 9 × 4 mm, margin entire, persistent. Male flower: pedicel deep red, 3–4 mm; tepals 2, cream or white slightly pink towards the base, broadly elliptic, 4.5–6 × 4 mm, with sparse stiff hairs outside, margin entire; stamens 22–25, cluster globose, stalk ca. 0.5 mm long; filament ca. 0.5 mm long, anthers pale yellow, obovate, ca. 1.5 × 0.5 mm, apex rounded. Female flower: pedicel 5–7 mm, rosy red, densely hairy; ovary pale green or white, triangular in outline, 18–26 × 10–23 mm, wings 3, bright red or pale green, equal, locules 3, placental branches 2 per locule; tepals 5, cream or whitish green and slightly pinkish towards the base, inner one smaller, elliptic, 6–10 × 5–7 mm, margin toothed towards apex; styles 3, pale yellow, 3 mm long, free to the base, bifurcating with pale yellow stigma forming a continuous twisted papillose band with whitish hairs. Fruits pendent; pedicel green, (7–) 12–14 mm long, stiff and recurved; capsule glossy green, with sparse short hairs, triangular in outline, narrowed proximally, distally widening to a truncate apex, 35–45 mm long, 17–27 mm wide, glabrous, locules 3, wings equal, 8–14 mm wide at the widest point, stiffly papery, dehiscing between the wings and locules. Seeds barrel-shaped, ca. 0.4 × 0.2 mm, collar cells more than half the length of the seeds.

Distribution: — MALAYSIA. Borneo. Sarawak. Marudi District: Gunung Mulu National Park. Endemic in the Melinau limestone. Found along the trail from Lobang Cina to Camp 5, Bukit Agung, Deer Cave, Kuala Litut to Camp 5.

Habitat: —In lowland limestone forest on limestone-derived soil sometimes on low, periodically flooded areas below 250 m elevation.

Etymology: —Named because it is commonly encountered in lowland limestone.

Additional specimens examined (paratypes): — MALAYSIA. Borneo. Sarawak. Marudi District: Gunung Mulu National Park – Near boardwalk to Deer Cave , Julia et al. S 99209 ( E, KEP, SAN, SAR, SING), S 99210 ( K, KEP, SAR, SAN); Trail to Kuala Litut , Julia et al. S 99211 ( E, K, KEP, L, SAR, SING); Melinau Gorge , Sub-camp 5, Lewis 315 ( SAR); Bukit Agung , Julia et al. SFC 2815 ( E, K, KEP, L, SAR, SING); Lobang Cina, Julia et al. SFC 3012 ( E, K, KEP, SAR), Julia et al. SFC 2806 ( K, KEP, L, SAN, SAR, SING) .

Notes: —Several other cane-like limestone begonias, such as Begonia lailana Kiew & Geri (2003: 117) , B. meriraiensis and B. paoana Kiew & S.Julia (2007: 217) , all have slightly oblique, oblanceolate leaves with large fruits where the wings diverge distally so that the fruit appears triangular in outline. This new species belongs to this group that all grow on limestone-derived soils rather than directly on the limestone rock.

Figures

FIGURE 15. Begonia vulgare. A. bushy and much branched habit; B. protogynous panicle inflorescence showing fruit and male flowers; C. female flower; D. fruits. Photos from SFC 2815 by Connie Geri.