Begonia longifolia Blume, 1823

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 : 58-60

Begonia longifolia Blume [sect. Sphenanthera ]

Fig. 37

Catalogus: 102 ( Blume 1823). – Diploclinium longifolium (Blume) Miq., Flora van Nederlandsch Indie 1 (1): 687 ( Miquel 1856). – Type: Indonesia, Sumatra, Salak, Blume 740 (lecto-: B100238313, here designated).

Casparya trisulcata A.DC., Annales des Sciences Naturelles; Botanique, Sér. 4, 11: 119 (de Candolle 1859). – Begonia trisulcata (A.DC.) Warb., Naturlichen Pflanzenfamilien 3 (abt. 6a): 142 ( Warburg 1894). – Type: Indonesia, Java, Mt. Jojing, 1 May 1845, Zollinger 2850 (lecto-: G-DC, here designated; isolecto-: B, BM, P01900669).

Begonia inflata C.B.Clarke, Flora of British India 2: 636 ( Clarke 1879). – Type: Myanmar ‘Birma’, Griffith 2587 (lecto-: K000761388; isolecto-: B, GH00091698, K000761387, P05587760).

Begonia sarcocarpa Ridl. , Journal of the Federated Malay States Museums 8 (4): 38 ( Ridley 1917a). – Type: Indonesia, West Sumatra, Korinchi, Barong Baru, 5 Jun. 1914, Robinson & Kloss 61 (lecto-: BM000017330, here designated).

Begonia turbinata Ridl. , Journal of the Federated Malay States Museums 8 (4): 37 ( Ridley 1917a). – Type: Indonesia, West Sumatra, Korinchi, Siolak Dras, 15 Mar. 1914, Robinson & Kloss s.n. (lecto-: BM000017335; isolecto-: BM, K000761216).

Begonia tricornis Ridl. , Journal of the Straits Branch of the Royal Asiatic Society 75: 35 ( Ridley 1917b). – Type: Malaysia, Pahang, Telom, Nov. 1900, Ridley 14123 (lecto-: SING0055970, here designated; isolecto-: K000501077).

Begonia crassirostris Irmsch., Mitteilungen aus dem Institut für allgemeine Botanik in Hamburg 10: 513 ( Irmscher 1939). – Type: China, Hainan, Lam Ko District, Lin Fa Shan, 2 Aug. 1927, Tsang Wai Tak 278 (lecto-: E00051639; isolecto-:, G n.v., K000761123, MO n.v., UC n.v.).

Begonia roxburghii auct . non (Miq.) A.DC.: Ridley in Journal of the Federated Malay States Museums 4: 20 ( Ridley 1909).

Begonia roxburghii auct . non (Miq.) A.DC.: Ridley in Flora of the Malay Peninsula 1: 854 ( Ridley 1922).

Citations in other publications

As B. longifolia: Blume (1827: 97) , de Candolle (1864: 398), Koorders (1912: 650), Tebbitt (2003a: 25), Tebbitt (2005: 168), Kiew (2005: 107), Gu et al. (2007: 184), Hughes (2008: 72), Peng & Ku (2009: 241), Morris (2010c: 6), Hughes & Girmansyah (2011: 29); as Casparya trisulcata: de Candolle (1864: 277) , Warburg (1894: 142); as B. inflata: Clarke (1881: 115) , Burkill (1924: 412), Craib (1931: 774), Grierson (1991: 242), Tebbitt (2003a: 25), Uddin (2007: 594), Dash (2010: 34); as B. sarcocarpa: Tebbitt (2003a: 27) ; as B. turbinata: Tebbitt (2003a: 28) ; as B. tricornis: Tebbitt (2003a: 25) ; as B. crassirostris: Tebbitt (2003a: 25) .

Other material

INDIA: Arunachal-Pradesh: Babuk, Nov. 1911 – Mar. 1912, Burkill 37656 (n.v.); Igar Valley, Nov. 1911 – Mar. 1912, Burkill 37523 (n.v.); Kalek, Nov. 1911 – Mar. 1912, Burkill 37564 (n.v.); Mouth of the Sirsug River, 30 Dec. 1911, Burkill 37586 ( K); Tidding Valley, Theronhaing, 9 Mar. 1927, Ward 7936 ( K). Meghalaya: Shillong, Pangu-Minguing, 16 May 1958, Rao 17711 ( CAL n.v.). Mizoram: Hmuifang, Dec. 1927, Parry 430 ( K).

Description

Caulescent, erect, monoecious herb, 50–200 cm high. Stem: stout, ca 10 mm wide, glabrous, internodes 3–8 cm long. Stipules: lanceolate to linear, 7–15 × 2–5 mm, glabrous, deciduous. Leaves: petiole 2–7(–14) cm long, glabrous or very sparsely puberulous; lamina lanceolate-oblong, basifixed, base shallowly cordate to subcordate, 4.5–22 × 1.5–10 cm, strongly asymmetric, upper surface dark green, glabrous, underside pale green, glabrous or sparsely puberulous on veins mostly, venation palmatepinnate, midrib 4.5–15 cm long; margin broadly dentate to denticulate; margin with sparse hairs to glabrous; apex acuminate. Inflorescence: cymose, axillary, numerous; peduncle glabrous, branching 1–2 times, primary and secondary 2–10 mm long, with 1– 2 female and 1– 3 male flowers; bracts lanceolate, 2–12 × 1–5 mm, entire, caduceus. Male flower: pedicel 5–13 mm long, glabrous; tepals 4; outer tepals orbicular to obovate, ca 10 × 9 mm, white to pink, glabrous; inner tepals spathulate, 4–8 × 2–7 mm, white to pink, glabrous; androecium with 30–60 stamens, symmetric; filaments 1–1.5 mm long, free; anthers oblong elliptic, 1–3 mm long, dehiscing through slits about half the length of the anther, not hooded, connective extended. Female flower: pedicel ca 14 mm long, glabrous; bracteoles absent; tepals 4–6, equal, elliptic, 5–16 × 2–6 mm, white to pale pink, glabrous, inner tepals similar yet smaller; ovary 3-locular, placentae bifid; capsule globose, 3–10 × 3–7 mm, glabrous, without wings; styles 3, deeply forked once and twisted twice, deciduous. Fruit: on stout pedicel, globose; capsule spherical, fleshy, glabrous, 6–12 × 8–15 mm.

Distribution and phenology

Arunachal-Pradesh and Meghalaya; also in China, Myanmar, Thailand, Malaysia Peninsular, Vietnam, Sumatra, Java, Lesser Sunda Islands, Sulawesi and the Moluccas; 200–1550 m. Flowering: May to November; fruiting: June to December.

Conservation status

Least Concern ( Hughes 2008). Begonia longifolia is a very widespread and ecologically tolerant species found throughout Southeast Asia, with no significant change in recent years to warrant a change in its status.

Remarks

Begonia longifolia is most similar to B. acetosella in vegetative appearance; when fertile it can be easily distinguished as it is monoecious and has 3- (not 4-)locular fruit. The leaves of B. longifolia can approach those of B. sect. Monopteron ( B. griffithiana and B. nepalensis ), but B. longifolia has an upright habit rather than the pendulous habit of those species. Begonia longifolia forms a natural hybrid with B. palmata where the two are growing together, Begonia × chungii C.I Peng & S.-M.Ku ( Peng & Ku 2009) which has been reported from the study area ( Morris 2011a). This hybrid has baccate fruit with wings, intermediate in form between the parents.

Begonia longifolia is lectotypified here as others ( Tebbitt 2003a; Kiew 2005; Gu et al. 2007; Hughes & Girmansyah 2011) have listed a holotype in error as there is no herbarium mentioned in the protologue ( McNeill 2014). This is also true of Casparaya trisulcata , B. sarcocarpa and B. tricornis .