A revision and one new species of Begonia L. (Begoniaceae, Cucurbitales) in Northeast India Author Camfield, Rebecca Royal Botanic Gardens Edinburgh, 20 a Inverleith Row, Edinburgh, EH 5 3 LR, United Kingdom. RCamfield@rbge.org.uk Author Hughes, Mark Royal Botanic Gardens Edinburgh, 20 a Inverleith Row, Edinburgh, EH 5 3 LR, United Kingdom. MHughes@rbge.org.uk text European Journal of Taxonomy 2018 2018-01-19 396 1 116 journal article 10.5852/ejt.2018.396 2b95a851-e1bf-4bdd-9cce-441ddc4135d2 2118-9773 3787049 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 Fig. 40. Map showing the location of B. nepalensis (A.DC.) Warb. specimens. 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.