Begonia (sect. Sphenanthera) longifolia Blume (Blume 1823

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.