Begonia rex Putz. [sect. Platycentrum]

Figs 50–51

Flores des Serres et des Jardins de l’Europe 12: 141 (Putzey 1857).

– Type: Fl. Serr. Jard. 12: 141-[illustration]; India, Nagaland, Naga Hills, Digboi, Jan. 1969, Yandall 109 (epi-: K, here designated).

Citations in other publications

Koch (1858: 337), Hooker (1859: tab. 5107), de Candolle (1864: 350), Clarke (1879: 647), Clarke (1881: 119), Clarke (1890: 25), Gagnepain (1921: 1112), Burkill (1924: 288), Fischer (1938: 98), Deb (1961: 285), Kumar (2002: 650), Kress et al. (2003: 171), Gu et al. (2007: 195), Uddin (2007: 594), Hughes (2008: 107), Khatun (2008: 11), Morris (2009a: 133), Dash (2010: 39).

Other material

INDIA: Arunachal-Pradesh: Bapu Mountain, Rotung, Nov. 1911 – Mar. 1912, Burkill 37374 (n.v.); Chambang to Kurung River, Dash 32963 (ARUN n.v.); Deban, Pal 7333 (ARUN n.v.); Delei Valley, 14 Aug. 1928, Ward 8518 (K). Assam: Griffith 2588 (K); ibid., Griffith 2589 (K); Khasia, Griffith 2592 (K); Königreich [Assam Kingdom], Lips. s.n. (B). Nagaland: Naga Hills, Digboi, Jan. 1969, Yandell 108 (K); ibid., Jan. 1969, Yandall 109 (K); Naga Hills, Mariani District, Lakhuni, 2 Jan. 1949, Ward 18376 (BM) [cf. B. rex].

Description

Rhizomatous, monoecious herb, 20–40 cm high. Rhizome: 5–10 mm wide, pilose. Stipules: ovate to lanceolate, 7–15 × 2–18 mm, sparsely villose, persistent. Leaves: petiole 10–20 cm long, densely to sparsely red villose; lamina ovate, basifixed, base cordate with lobes almost overlapping, (5–)10–20 × 5–15 cm, asymmetric, upper surface dark green with pale ring marking or dark green/red edges with pale ring and dark centre, glabrous or very sparsely pilose, underside green and red about veins, or with red veins, red villose denser on veins, venation palmate, midrib (4–) 6.5–18 cm long; margin entire to repand, with long hairs; apex acute. Inflorescence: cymose, terminal, few; peduncle glabrous, branching 1–2 times, primary 4–10 cm long, secondary 7–9 mm long, with 2– 4 female and 2– 6 male flowers; bracts ovate, 5–12 × 3–5 mm, glabrous, margin entire, deciduous. Male flower: pedicel 18–35 mm long, glabrous; tepals 4; outer tepals ovate, 12 –20 × 8–17 mm, pink to dark pink, glabrous, margin entire; inner tepals spathulate, 8–18 × 3–8 mm, pink to pale pink, glabrous; androecium with 70 –120 stamens, symmetric; filaments 2–5 mm long, unequal, fused at base into a long column; anther ellipticglobose, 1–3 mm long, dehiscing through slits running nearly the entire length of the anther, not hooded, connective extended, acuminate on apical stamens. Female flower: pedicel 11–31 mm long, glabrous; bracteoles absent; tepals 5, equal, oblong-ovate, 9–20 × 3–17 mm, pink, glabrous, margin entire, inner tepals similar but smaller; ovary 2-locular, placentae bifid; capsule ellipsoid, glabrous, with one long oblong wing and two short triangular wings; styles 2, deeply forked once and twisted twice, persistent. Fruit: recurved, 9–13 × 21–31 mm; capsule ellipsoid to broadly ellipsoid, 9–13 × 4–6 mm, glabrous; wings extending along the pedicel slightly, subequal; longest rounded oblong, 15–20 × 5–7 mm; shortest semi-circular, 2–5 × 8–10 mm.

Distribution and phenology

Arunachal-Pradesh, Assam and Nagaland; also in China, Bangladesh and Myanmar; 200–1250 m. Flowering: January; fruiting: January to February.

Conservation status

Data Deficient. Although this species is well known in cultivation, there are very few wild collections making calculating the AOO and EOO difficult. However, it is assigned to Least Concern due to the species having a wide distribution with ample habitat in Arunachal-Pradesh, Myanmar and China. The species has been found in the Namphada Reserve and Wallong National Park within the study area.

Remarks

The leaves usually have distinctive three-coloured variegation, with the paler central lamina contrasting with the darker margin and basal area; some bi-coloured and darker forms exist. The epitype Yandall 109 (K) was chosen as it shows similar leaf patterning to the type illustration. The acuminate anthers are distinctive, and also found in B. xanthina, which differs in having yellow flowers and spotted leaves. Begonia rex shares banded variegation with B. annulata, which differs considerably in leaf shape.