Begonia adscendens C.B.Clarke, 1890

Camfield, Rebecca & Hughes, Mark, 2018, A revision and one new species of Begonia L. (Begoniaceae, Cucurbitales) in Northeast India, European Journal of Taxonomy 396, pp. 1-116 : 15-18

Begonia adscendens C.B.Clarke [sect. Diploclinium ]

Figs 8–9

Journal of the Linnean Society, Botany 25: 26 ( Clarke 1890). – Type: India, Nagaland, Naga Hills, Jakpho, 25 Oct. 1885, Clarke 41240 (lecto-: K000634623, here designated; isolecto-: CAL n.v.).

Begonia obversa auct . non C.B.Clarke: Chauhan in Flora of Manipur: 425 ( Chauhan 2000).

Citations in other publications

As B. adscendens: Uddin (2007: 591) , Hughes (2008: 3), Uddin et al. (2008: 53).

Other material

INDIA: Manipur: Esii Hill, 1 Sep. 2006, Mao & Gogoi 109408 (ASSAM n.v.). Nagaland: Naga Hills, Jakpho, Clarke 41247 ( CAL n.v.).

Description

Tuberous, monoecious herb, 30–50 cm high. Stipules: ovate, 2 × 1–2 mm, glabrous, caduceus. Leaves: petiole 5–15 cm long, glabrous; lamina ovate to broadly ovate, basifixed, base cordate with lobes not overlapping, 4–16 × 2–22 cm, slightly asymmetric, upper surface green, glabrous, underside pale green or pale green with red markings, puberulous on veins mostly, venation palmate; midrib 3.5–13 cm long; margin toothed at the end of the veins with smaller teeth between, with sparse hairs; apex shortly acuminate. Inflorescence: cymose, terminal, few; peduncle glabrous, branching 1–2 times, primary 10–18 cm long, secondary 1–4 cm long, with 2– 4 female and 2– 6 male flowers; bracts not seen. Male flower: pedicel 8–13 mm long, glabrous; tepals 4; outer tepals orbicular to ovate, 10–18 × (5–) 9–12 mm, white to pink, sparsely pale puberulous on reverse, near the base, margin entire; inner tepals narrowly elliptic, 5–7 × 1–3 mm, white to pink, glabrous; androecium with 16–20 stamens, asymmetric; filaments 1–1.5 mm long, unequal, fused at base into a short column; anther oblong elliptic, 1 mm long, slightly hooded, connective not extended. Female flower: pedicel 8–18 mm long, glabrous; bracteoles absent; tepals 4–5, unequal, ovate, outer tepals, 8–15 × 5–7 mm, white tinted pink, sparsely puberulent on reverse, margin entire, inner tepals as in male; ovary 3-locular, placentae bifid; capsule globose-ellipsoid, glabrous, with one long triangular wing and two short triangular wings; styles 3, convoluted with slightly twisted ends, persistent. Fruit pendulous; capsule globose-ellipsoid 6–10 × 4–6 mm, glabrous; wings extending along the pedicel slightly, unequal; longest wing rounded oblong, 26–28 × 7–8 mm; shortest wings triangular, 3 × 1–3 mm.

Distribution and phenology

Manipur and Nagaland; also in Myanmar and Laos; 2400–2600 m. Flowering: September to October; fruiting: October.

Conservation status

Least Concern. Current data for B. adscendens gives an EOO of 113,895 km 2 and an AOO of 32 km 2. This sample size is low, but the specimens are widespread. The data would suggest this species is vulnerable but due to the distribution and supply of suitable habitat this species is classed as least concern. This species is found throughout the Arakan mountains and into the mountains of Northern Myanmar, both of which have extensive areas of suitable habitat.

Remarks

This species is similar to B. labordei which differs in having hairy leaves and dark purple hairs on the exterior of the male flowers that are visible without a microscope; the hairs are pale and near the base of the tepals in B. adscendens . The two species also differ in fruit wing shape; the longest wing curves adaxially on B. labordei but on B. adscendens it reaches up past the apex of the fruit capsule. This species is one of the highest altitude Begonia in Northeast India.

Figures

Fig. 8. Map showing the location of B. adscendens C.B.Clarke specimens.

Fig. 9. Illustration of B. adscendens C.B.Clarke by J. Allen (Clarke 1890). a. Dissected fruit capsule. b. Fruit cross-section diagram. Image courtesy of RBGE library and Lynsey Wilson.