Begonia burkillii Dunn, 1920

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 : 26-30

Begonia burkillii Dunn [sect. Sphenanthera ]

Figs 16–18

Bulletin of Miscellaneous Information, Kew 1920: 110 ( Dunn 1920). – Type: India, Arunachal-Pradesh, Janak river, Nov. 1911 – Mar. 1912, Burkill 37139 (lecto-: K000634633, here designated; isolecto-: B n.v.).

Citations in other publications

Burkill (1924: 288), Tebbitt (2003b: 7), Morris (2006: 88), Uddin (2007: 593), Hughes (2008: 22), Morris (2009b: 173), Dash (2010: 32), Saika et al. (2011: 357), Baruah & Choudbury (2014: 41).

Other material

INDIA: Arunachal-Pradesh: Abor Hills, Jauamukh, Nov. 1911 – Mar. 1912, Burkill 37121 ( CAL n.v.); Bapu Mountain, Renging Camp, Nov. 1911 – Mar. 1912, Burkill 36720 ( K); Bapu Mountain, Rotung, Burkill 37706 ( CAL n.v.); Bapu Mountain, Talauma, Nov. 1911 – Mar. 1912, Burkill 36910 (n.v.); Changlang, Namdapha Biosphere Reserve, Anamica Falls, 30 Nov. 2004, Amad Uddin 107934 (ASSAM); Dihang Valley, 12 Feb. 1928, Ward 7822 ( BM, K); Igar Valley, 29 Nov. 1911 – 11 Mar. 1912, Burkill 16121 (n.v.); Janak river, Nov. 1911 – Mar. 1912, Burkill 37455 ( K); Naharlagun, Pal 70320 ( ARUN n.v.); Papum Pare, 3 Apr. 2005, Morris AR2 ( CLEMS n.v.); Pasighat, 10 Feb. 1928, Ward 7822 ( K); Ponging, Nov. 1911 – Mar. 1912, Burkill 37375 (n.v.); Sangram to Panyu River, Dash 32511 ( ARUN n.v.); Serpo stream, Nov. 1911 – Mar. 1912, Burkill 36315 (n.v.); Shile River, Burkill 37121 (n.v.); Subansiri District, 8 Apr. 2005, Morris 12 ( CLEMS n.v.). Assam: Cacchar, Sonapur, 13 Jan. 2011, Himu Roy 143 ( GUBH); Dhemaji, Silapathar, Poba Reserve Forest, 13 Jan. 2010, Ranjit Saika 300 ( GUBH).

Description

Rhizomatous, dioecious herb, 20–40 cm high. Rhizome: ca 10 mm wide, glabrous, internodes 4–6 mm long. Stipules: lanceolate, 5–17 × 2–7 mm, glabrous, persistent. Leaves: petiole 5–15(–25) cm long, glabrous; lamina ovate-lanceolate to ovate, basifixed, base cordate with lobes almost overlapping, (4–)10–20 × (3–) 6–9 cm, asymmetric, upper surface variegated green and brown with a dark centre, glabrous or sparsely puberulent, underside variegated red and green, sparsely puberulent to glabrous, venation palmate-pinnate, midrib (3–) 8–18 cm long; margin entire to shallow dentate, glabrous; apex shortly acuminate. Inflorescence: cymose, axillary, several; peduncle glabrous, branching twice, male primary 5–15 cm, secondary 2–4 cm, 2–6 flowers, female primary 4–6 cm, 1(–2) flowers; bracts lanceolate, 6–20 × 1–5 mm, deciduous. Male flower: pedicel 13–25(–35) mm long, glabrous; tepals 4; outer tepals narrowly ovate, 10–30 × 7–16 mm, white to pink, glabrous, margin entire; inner tepals elliptic-obovate, 10–20 × 3–7 mm, white to pink, glabrous; androecium with 40 –70 stamens, symmetric; filaments 1–3 mm long, unequal, free; anther elliptic-obovate, 2 mm long, dehiscing through slits about half the length of the anther, not hooded, connective extended. Female flower: pedicel glabrous; bracteoles absent; tepals 4, similar to those of the male flower; ovary 4-locular, placentae bifid; capsule rhomboid, with 4 fleshy triangular wings/ridges; styles 4, forked once and twisted twice, deciduous. Fruit: on a stout pedicel, rhomboid; capsule oblong-ellipsoid, 20 × 4–11 mm, puberulous to glabrous, with 4 stubby wings or horns.

Distribution and phenology

Arunachal-Pradesh and Assam; also in Myanmar; 300–1100 m. Flowering: February to March; fruiting: February to April.

Conservation status

Least Concern. Begonia burkillii has an EOO of 83,400 km 2 and an AOO of 72 km 2, with a wide distribution through undisturbed forest in Arunachal-Pradesh and into Northern Myanmar.

Remarks

Specimens from the region lacked female flowers, which are described based on the protologue and photographs of cultivated plants. The leaf markings can vary in colour from red to purple-brown to almost black, but keep the same pattern ( Fig. 17 ). This species is perhaps most similar to B. handelii in being rhizomatous and having 4-locular fruit, but that species has large rounded outer petals (not narrowly ovate), non-variegated leaves and fruit that is more pyramidal than rhomboid.

The lectotypification by Saikia et al. (2011) list two specimens (Burkill 37706 and 37121) and hence is not valid. Here Burkill 37139 (K) is designated as the lectotype.

Figures

Fig. 17. Begonia burkillii Dunn. A. Leaf pattern. B. Male flowers. Photograph A courtesy of Aaron Matsumoto and photograph B courtesy of Earl I-Lan of plants in cultivation in private collections.