Begonia megaptera

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 : 61-63

Begonia megaptera A.DC. [sect. Platycentrum ]

Fig. 39

Annales des Sciences Naturelles; Botanique, Sér. 4, 11: 134 (de Candolle 1859). – Type: India, Sikkim, 1820–2420 m, Hooker 8 (lecto-: K, here designated).

Citations in other publications

de Candolle (1864: 348), Clarke (1879: 646), Clarke (1881: 119), Clarke (1890: 25), Fischer (1938: 98), Hara (1966: 214), Hara et al. (1979: 182), Grierson (1991: 245), Kumar (2002: 647), Kress et al. (2003: 171), Uddin (2007: 594), Hughes (2008: 80), Khatun (2008: 10), Dash (2010: 35).

Other material examined

INDIA: Arunachal-Pradesh: Lohit Valley, 13 Feb. 1950, Ward 19146 ( BM); Mishmi Hills, Kamlang River, 18 Mar. 1949, Ward 18420 ( BM). Meghalaya: Garo Hills, Nokrek, 7 Mar. 1950, Chand 2753 ( MICH); ibid., 7 Mar. 1950, Chand 2759 ( MICH); ibid., 7 Mar. 1950, Koelz 24605 ( MICH); Garo Hills, Tura Mountain, 20 Nov. 1929, Parry 839 ( K); ibid., Oct. 1929, Parry 839 ( K). Mizoram: Lushai Hills, 1929, Parry 839 ( K); ibid., 1934, Parry s.n. ( K); Lushai Hills, Thenzawl, May 1928, Parry 253a ( K). Nagaland: Naga Hills, Nichuguard, 17 Oct. 1885, Clarke 40854A ( BM); ibid., Clarke 40854D ( K); ibid., Clarke 40854G ( K).

Description

Rhizomatous, erect, monoecious herb, to ca 40 cm high. Stem: stout, ca 5 mm wide, glabrous, internodes 8–13 cm long. Stipules: lanceolate, 12–15 × 6–9 mm, glabrous, semi persistent. Leaves: petiole 4–20 cm long, glabrous; lamina ovate-orbicular to ovate, basifixed, base cordate with lobes overlapping or not, 8.5–25 × 5–16 cm, asymmetric, upper surface green, glabrous, underside green, glabrous or sparsely puberulent on the veins, venation palmate, midrib 6–18 cm long; margin broadly dentate, appearing scalloped between main veins, with sparse hairs; apex acuminate. Inflorescence: cymose, axillary, few; peduncle glabrous, branching 2–3 times, primary 10–25 cm, secondary 3–8 cm, tertiary 3–5 mm, with 2– 4 female and 4– 6 male flowers; bracts ovate to lanceolate, 10–20 × 3–14 mm, margin entire, deciduous. Male flower: pedicel ca 20 mm long, glabrous; tepals 4; outer tepals broadly ovate to orbicular, 7–15 × 4–9 mm, pink to white, glabrous, margin entire; inner tepals ovate to lanceolate, 4–7 × 2–6 mm, pink to white, glabrous; androecium with 50–60 stamens, symmetric; filaments 1–3 mm long, unequal, slightly fused at the base into a column; anther oblong elliptic, 1–2 mm long, dehiscing through slits longer than half the length of the anther, not hooded, connective not extended. Female flower: pedicel 12–16 mm long, glabrous, bracteoles absent; tepals 5, equal, ovate, outer tepals 10–12 × 5–9 mm, pink to white, glabrous, margin entire, inner tepals similar yet smaller; ovary 2-locular, placentae bifid; capsule oblong-ellipsoid,glabrous,with one long oblong wing and two short rounded wings;styles2,forked once and twisted twice, deciduous. Fruit: recurved; capsule oblong-ellipsoid, 14–18 × 3–10mm, glabrous; wings extending along the pedicel slightly, unequal; longest wing rounded oblong, 15–34 × 8–12 mm; shortest wing semi-circular, 3–7 × 10–15 mm.

Distribution and phenology

Arunachal-Pradesh, Meghalaya, Mizoram and Nagaland; also in Nepal, Sikkim, Bhutan, Bangladesh and Myanmar; 500–1250 m. Flowering: August to November; fruiting: October to March.

Conservation status Least Concern. Begonia megaptera has an AOO of 40 km 2 and an EOO of 220,500 km 2 with ample

suitable habitat in the Himalayas and Arakan mountains. The populations in the Garo-Khasi Hills of Meghalaya are at risk due to deforestation. The species has been found near the Blue Mountain National Park of Mizoram, Nokrek National Park of Meghalaya and Namphada Reserve of Arunachal-Pradesh.

Remarks

Begonia megaptera is superficially similar to B. palmata but can instantly be distinguished as it lacks the reddish brown silky indumentum. The rather poorly known B. beddomei also has similar scalloped leaves, but has female flowers with 8 tepals and hairs on the petioles and leaf lamina underside.