Begonia nepalensis

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 : 63-65

Begonia nepalensis (A.DC.) Warb. [sect. Monopteron]

Figs 26B , 40

Naturlichen Pflanzenfamilien 3 (abt. 6a): 142 ( Warburg 1894). – Mezierea nepalensis A.DC., Annales des Sciences Naturelles; Botanique, Sér. 4, 11: 144 (de Candolle 1859). – Type: Nepal, Chireeaghatte, 1820, Wallich Cat. No. 3677 (lecto-: K-W, barcode K000761414, here designated; isolecto-: BM001122244, BM001122245, E00300428, K000761415).

Begonia gigantea Wall. ex C.B.Clarke, The Flora of British India 2: 643 ( Clarke 1879) nom. illegit. superfl. – Type: Nepal, Chireeaghatte, 1820, Wallich Cat. No. 3677 (lecto-: K-W, barcode K000761414; isolecto-: BM001122244, BM001122245, E00300428, K000761415).

Begonia gigantea Wall., A numerical list of dried specimens of plants in the East India Company’s Museum: 129, 3677B ( Wallich 1831), nom. nud.

Citations in other publications

As B. nepalensis: Hara et al. (1979: 182) , Grierson (1991: 243), Morris (2006: 88), Morris & McMillan (2006: 174), Uddin (2007: 594), Hughes (2008: 89), Dash (2010: 35), Saika et al. (2011: 357); as Mezierea nepalensis: de Candolle (1864: 406) ; as B. gigantea: Clarke (1881: 119) , Burkill (1910: 110).

Other material

INDIA: Arunachal-Pradesh: Chopia Forest, Rao 56411 (ASSAM n.v.); Kameng District, Aka Hills, Bor 15703 (ASSAM n.v.); Kameng District, Sessa Forest, Singh 97230 (n.v.).

Description

Caulescent, cascading, monoecious herb, 75 –100 cm. Stem: stout, 5–10 mm wide, glabrous. Stipules: lanceolate, deciduous. Leaves: petiole 1–3 cm long, glabrous; lamina ovate-lanceolate, basifixed, base cordate with lobes not overlapping, 15–27 × 4–11 cm, strongly asymmetric, upper surface green, glabrous, underside green, puberulous on veins only, venation palmate-pinnate; margin shallowly dentate; apex caudate-acuminate. Inflorescence: cymose, axillary, numerous; peduncle glabrous, branching 2–3 times, primary 2–4 cm, secondary 0.5–2 cm, tertiary 0.5–1 cm, with 6– 8 female and 2– 6 male flowers; bracts not seen. Male flower: pedicel 1–2 cm long, glabrous or puberulent; tepals 2, ovate, 7–10 × 7–9 mm, white to pale pink, glabrous; inner tepals usually absent, one if present, narrowly elliptic, 7 × 2 mm, glabrous; androecium with 20–40 stamens, symmetric; filament 1 mm long, fused at base into a short column; anther elliptic globose, 1 mm long, dehiscing through short slits near the tip, connective slightly extended. Female flower: pedicel 2–3 cm, glabrous or puberulent; bracteoles absent; tepals 4–5, equal, ovate, outer tepals 10–15 × 7–10 mm, white to pale pink, glabrous, margin entire, inner tepals similar yet smaller; ovary 2-locular, placentae bifid, capsule narrowly ellipsoid, glabrous, with one long triangular-oblong wing and two very narrow ridges; styles 2, convoluted with ends twisted once. Fruit: pendulous; capsule narrow ellipsoid, 12–15 × 5 mm; wing oblong, 15–23 × 10–15 mm.

Distribution and phenology

Arunachal-Pradesh, Assam, Meghalaya and Mizoram; also in Nepal, Sikkim, Bhutan and Myanmar. Flowering: November to February; fruiting: December to February.

Conservation status

Least Concern. Begonia nepalensis has an AOO of 48 km 2 and an EOO of 160,000 km 2 with ample suitable habitat within its range in the Eastern Himalayas. The species has been found near Makalu

Baran National Park of Nepal, Pakke Tiger Reserve of Arunachal-Pradesh and Buxa Wildlife Sanctuary of West Bengal.

Remarks

The species is illustrated in Morris & McMillan (2006) and Morris (2011d). Begonia nepalensis is most similar to B. griffithiana ; see diagnostic notes under that species.

Figures

Fig. 26. Difference in fruit shape. A. B. griffithiana (A.DC.) Warb. B. B. nepalensis (A.DC.) Warb. Drawn by Rebecca Camfield. A from Griffith 203 (K) and 2504 (K); B from Stainton 8906 (E) and Cave s.n. (E00013877).

Fig. 40. Map showing the location of B. nepalensis (A.DC.) Warb. specimens.