Begonia simolapensis Ardi, 2015

Hughes, Mark, Girmansyah, Deden & Ardi, Wisnu Handoyo, 2015, Further discoveries in the ever-expanding genus Begonia (Begoniaceae): fifteen new species from Sumatra, European Journal of Taxonomy 167, pp. 1-40 : 35-36

Begonia simolapensis Ardi sp. nov. § Reichenheimia

urn:lsid:ipni.org:names:77151652-1

Figs 2 , 17

Diagnosis

Begonia simolapensis grows sympatrically on limestone with B. olivacea described above and has a similar habit (growing flat against the substrate) and leaf shape; it differs in having larger (5–9.5 × 4–8 cm, not 2.7–4.5 × 2.6–3.7 cm), glossier leaves which are a nearly uniform deep green (not olive green with paler variegation) and longer, denser hairs on the petioles.

Etymology

The epithet refers to the type locality of Simolap.

Type

SUMATRA: North Sumatra Province, Leuser National Park, Simolap, 260 m, 9 Jul. 2011, Puglisi et al. 228 (holo-: BO; iso-: E).

Additional material

SUMATRA: North Sumatra, Gunung Leuser National Park, Simolap, 11 Jul. 2011, Puglisi 267 ( BO, E).

Description

Repent acaulescent herb, growing flat against vertical rocks or soil on limestone, less than 15 cm tall; stem rhizomatous, internodes c. 2 mm long. Stipules persistent, triangular, 4–5 × 5 mm, with an abaxially prominent midrib that extends up to 6 mm. Leaves: petiole 3–14 cm long, shorter towards the plant apex, terete, sparsely hairy; lamina suborbicular, asymmetric, 5–9.5 × 4–8 cm, basifixed, base cordate with lobes slightly overlapping, adaxially green to reddish dark green, glossy, glabrous, abaxially pale green with hairs on veins only, primary veins 6–8, actinodromous, margin fimbriate and recurved stiff teeth at the end of the veins, apex obtuse. Inflorescences axillary, cymose, branching 1–3 times, bisexual, 6– 8 male flowers, 2– 4 female flowers, protandrous; primary peduncle c. 7–12 cm long, glabrous; bracts semi-persistent, elliptic or narrowly obovate, 2.5–3.5 × 1.5–2.5 mm, margin fimbriate, apex acute. Male flowers: pedicel c. 12 mm long, glabrous; tepals 4; outer tepals suborbicular, 9–11 × 8–12.5 mm, white or white with pink stripes, glabrous, slightly cordate at the base becoming truncate when open, margin entire; inner tepals narrowly obovate or elliptic, 4–8 × 3–4 mm, white; androecium pale yellow, symmetric, globose, stamens c. 40; filaments fused at base into a short column, c. 1–1.5 mm long; anther 0.75 mm long, obovate-obtriangular, dehiscing through slits slightly longer than half the length of the anther, apex retuse. Female flowers: pedicel 5–6 mm long; ovary green with red venation, glabrous, c. 7 × 15 including the wings; capsule ellipsoid, c. 7–8.5 × 4.5–5 mm, locules 3, placentae entire; wings 3, equal, cuneate at base and apex, widest point at the middle, c. 4 mm wide; tepals 3; outer tepals 2, white or white with pink stripes, suborbicular, c. 6–7 × 6.5–7.5 mm; inner tepal elliptic, 5.5–6.5 × 1–2 mm; stigmas 3, yellow, forked and once spirally twisted, caducous. Fruit recurved on a c. 6 mm long pedicel; wings the same as the ovary, capsule orbicular, 7.5 × 5.5 mm, total size 9 × 18 mm including wings; apex obtuse.

Distribution and habitat

North Sumatra to Aceh, Gunung Leuser National Park at 200–300 m altitude ( Fig. 2 ). The species grows terrestrially on soil over limestone slopes or directly on vertical limestone rock, half shade to full shade. Its distribution overlaps with that of B. olivacea , with which it hybridises (e.g. Puglisi et al. CP234, BO, E).

Conservation status

The limestone habitat of the Gunung Leuser National Park in the Simolap area where this species occurs is relatively intact. As long as this remains the case, B. simolapensis can be considered as being Least Concern ( IUCN 2012).

Figures

Fig. 2. Map of Sumatra showing the full known species distributions based on collection localities. Each point may represent more than one collection.

Fig. 17. Begonia simolapensis Ardi sp. nov. A. Habit. B. Male flower. C. Fruit on recurved pedicels. D. Female flowers. E. Male flower buds. All photographs from the type locality of Simolap. Scale bars on insets = 1 cm.