Begonia kemumuensis M.Hughes, 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 : 19-21

Begonia kemumuensis M.Hughes sp. nov. § Reichenheimia

urn:lsid:ipni.org:names:77151644-1

Figs 4 , 9

Diagnosis

Vegetatively B. kemumuensis is most similar to B. stictopoda Miq. (A. DC) (de Candolle 1864) in habit, although the leaves are acutely lobed (not entire) and the flowers are smaller (largest tepal c. 5 mm across, not c. 10 mm) with fleshy, cup-shaped tepals (not membranous flat tepals). The obtriangular anthers are also distinctive (elliptic in B. stictopoda ).

Etymology

The epithet is derived from the locality where this species was discovered, near the village of Kemumu.

Type

SUMATRA: Bengkulu, Bukit Daun, Kemumu waterfall, 380 m, 18 Aug. 2010, Girmansyah & Hughes DEDEN 1506 (holo-: BO; iso-: E).

Description

Erect acaulescent herb, 15–20 cm tall; stem rhizomatous, internodes c. 5 mm long, sparsely hairy, becoming glabrous with age. Stipules persistent, hairy on the keel, triangular, apex filiform. Leaves: petiole 7–10 cm long, terete, with 5 mm long white erect hairs and an undercoat of shorter appressed hairs; lamina, suborbicular, thin, asymmetric, 10–13 × 9–11 cm, basifixed, base cordate, sinus c. 1.5 cm, lobes overlapping, upper surface glabrous, underside with 1.5 mm long hairs on the veins, otherwise glabrous, venation palmate; margin sparsely denticulate, with 2–6 pointed short lobes c. 5–10 mm long. Inflorescences axillary, total length up to c. 25 cm, cymose, branching c. 4 times, with c. 30 flowers, bisexual, protandrous, primary peduncle 17–22 cm long, puberulent; bracts deciduous, basal pair suborbicular, c. 4 × 4 mm, with 1 mm long hairs, fimbriate, becoming obovate, smaller, entire and glabrous towards the inflorescence apex. Male flowers: pedicel c. 20 mm long for the first flower in the centre of the cyme, shorter to c. 4 mm long in the more distal parts, puberulent; tepals 4; outer 2 pink adaxially, fleshy, ovate, 5 × 4 mm; inner 2 white, membranous, elliptic 4 × 2 mm; androecium yellow, globose-cylindrical, symmetric, stamens c. 100, on a 2 mm long column; filaments subequal, 0.5 mm; anthers obtriangular, 0.5 mm long, connective retuse, dehiscing through slits the length of the anther, slits lateral. Female flowers not seen. Fruit recurved on a 5–8 mm long stiff pedicel, total size 4–6 × 10–12 mm, capsule orbicular, 5 mm in diameter, wings equal, rounded-triangular, c. 7 mm long; apex abtuse to truncate.

Distribution and habitat

Known only from the type locality along a forest trail near the old concrete dam by Kemumu waterfall in Bengkulu Province ( Fig. 4 ).

Conservation status

Known from a single location which is currently a well-managed recreation forest. The single location means the species is prone to the risk of extinction through chance events, so we consider the IUCN category of Vulnerable to apply using criterion VUD2 ( IUCN 2012).

Figures

Fig. 4. Map of Sumatra showing the full known species distributions based on collection localities. Each point may represent more than one collection.

Fig. 9. Begonia kemumuensis M.Hughes sp. nov. A. Habit. B. Fruit. C. Male flower. D. Stipules. E. Young inflorescence. A–C, E from the type locality of Kemumu waterfall; D from a plant in cultivation at the Royal Botanic Garden Edinburgh (accession 20101656, derived from the type DEDEN1506). Scale bars on insets = 1 cm.