Begonia sikkimensis A.DC.

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 : 88-90

Begonia sikkimensis A.DC. [sect. Platycentrum]

Fig. 57

Annales des Sciences Naturelles; Botanique, Sér. 4, 11: 134 (de Candolle 1859).

– Type: India, Sikkim, 1850, Hooker 14 (lecto-: K000761425 , here designated ; isolecto-: K000761424 ).

Citations in other publications

de Candolle (1864: 349), Clarke (1879: 646), Clarke (1881: 119), Clarke (1890: 25), Fischer (1938: 98), Hara (1966: 215), Hara et al. (1979: 182), Grierson (1991: 241), Hynniewta (1994: 183), Kumar (2002: 652), Kress et al. (2003: 172), Gu et al. (2007: 198), Uddin (2007: 595), Hughes (2008: 116), Dash (2010: 40).

Other material

INDIA: Arunachal-Pradesh: Buyang, Dash 32658 ( ARUN n.v.) ; ibid., Dash 32654 ( ARUN n.v.) ; Dirang dzong, 14 Aug. 1938, Ward 14074 ( BM) ; Mariyang, Choudhery 18489 ( ARUN n.v.) ; Palin, Pal 478 ( ARUN n.v.). Mizoram, Lushai Hills,Aijal, Sep. 1927, Parry 253 ( K) ; Vanlaiphai, Parry 253 (n.v.). Nagaland, Naga Hills, Kohima, 8 Jul. 1950, Koelz 25465 ( MICH) ; ibid., 12 Sep. 1950, Koelz 26170 ( MICH) ; Naga Hills, Takubama, 27 Aug. 1950, Chand 3467 ( MICH).

Description

Rhizomatous, erect, monoecious herb, 30–200 cm high. Rhizome: 10–15 mm wide, glabrous, internodes 1–3 cm apart. Stem: slightly woody, stout, ca 1 cm wide, glabrous, internodes 5–9 cm long. Stipules: lanceolate, 18 –27 × 3–7 mm, glabrous, caduceus. Leaves: petiole 5–15(–20) cm long, glabrous; lamina ovate-orbicular to broadly ovate, basifixed, base shallowly cordate, 10–24 × 11–25 cm, slightly asymmetric, upper surface green, or green with darker margin, glabrous, underside green, sparsely puberulous hairs on veins to glabrous, venation palmate, midrib 8–21 cm long; margin deeply lobed about main veins with fine serrations, mostly glabrous; apex acuminate. Inflorescence: cymose, axillary, few; peduncle glabrous, branching 2–3 times, primary 10 –20 cm, secondary 2–8 cm, tertiary 3–4 cm, with 2– 6 female and 2– 4 male flowers; bracts ovate to ovate-orbicular, 15–20 × 8–15 mm, margin entire, deciduous. Male flower: pedicel 10–22 mm long, glabrous; tepals 4; outer tepals ovate, 10–15 × 5–10 mm, pale pink to red, glabrous, entire; inner tepals ovate to oblong, 7–14 × 3–9 mm, pale pink, glabrous; androecium with 40–80 stamens, symmetric; filaments 1–2 mm long, unequal, fused at base; anther oblong elliptic, 1–1.5 mm long, dehiscing through slits longer than half the length of the anther, not hooded, connective extended. Female flower: pedicel 9–24 mm long, glabrous; bracteoles absent; tepals 5, equal, ovate, outer tepals 4–9 × 3–5 mm, pale pink to red, margin entire, inner tepals similar yet smaller; ovary 2-locular, placentae bifid; capsule oblong-ellipsoid, 4–7 × 2–5 mm, with one long oblong wing and two short oblong wings; styles 2, deeply forked once and twisted once, deciduous. Fruit: recurved, 12–17 × 17– 43 mm; capsule oblong-ellipsoid, 12–15 × 4–6 mm, glabrous; wings extending along the pedicel slightly, unequal; longest rounded oblong, 12–32 × 5–17 mm; shortest oblong, 1–5 × 7–11 mm.

Distribution and phenology

Arunachal-Pradesh, Mizoram and Nagaland; also in China, Tibet, Nepal, Sikkim and Myanmar; 150–2150 m. Flowering: July to September; fruiting: August to October.

Conservation status

Least Concern. Begonia sikkimensis has an AOO of 76 km 2 and an EOO of 494,000 km 2 with a

distribution encompassing ample suitable habitat. The species is found in several national parks in Nepal and near Moulling National Park in Arunachal-Pradesh and near the Khawnglung Wildlife Sanctuary in Mizoram.

Key to varieties:

1. Plant up to 1 m high, stems green, petioles 10–27 cm, leaves under 20 cm long, male flowers uniform pale pink, female flowers pale pink ......................... B. sikkimensis A.DC. var. sikkimensis

– Plant up to 2 m high, stems red to dark pink, petioles 3–23 cm, leaves can be over 20 cm long, male flowers outer tepals dark pink to red, inner tepals pale pink, female flowers tepals dark pink ........... B. sikkimensis A.DC. var. kamengensis Rekha Morris, P.D.McMillan & Golding ex Golding

Figures

Fig. 57. Map showing the location of B. sikkimensis A.DC. specimens.