Begonia aborensis 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 : 10-12

Begonia aborensis Dunn [sect. Sphenanthera ]

Fig. 5

Bulletin of Miscellaneous Information, Kew 1920: 109 ( Dunn 1920). – Type: India, Arunachal-Pradesh, Babuk, Nov. 1911 – Mar. 1912, Burkill 37663 (lecto-: K, here designated).

Citations in other publications

Burkill (1924: 289), Chauhan (1996: 174), Tebbitt & Guan (2002: 133), Morris (2006: 88), Uddin (2007: 592), Dash (2010: 31), Morris (2011c: 89).

Other material

INDIA: Arunachal-Pradesh: Abor Hills, Bapu Mountain, Renging Camp, Nov. 1911 – Mar. 1912, Burkill 36833 (n.v.); Abor Hills, Bapu Mountain, Rotung, Nov. 1911 – Mar. 1912, Burkill 36225 (n.v.); ibid., Nov. 1911 – Mar. 1912, Burkill 36825 ( K); Abor Hills, Dihang Valley, 12 Feb. 1928, Ward 7854 ( K); Igar Valley, Nov. 1911 – Mar. 1912, Burkill 37530 (n.v.); Kebang, Nov. 1911 – Mar. 1912, Burkill 37794 (n.v.); Mariyang, Choudhery 18405 ( ARUN n.v.); Pasighat, Nov. 1911 – Mar. 1912, Burkill 36999 (n.v.); Puak Camp, Nov. 1911 – Mar. 1912, Burkill 36132 (n.v.); ibid., Nov. 1911 – Mar. 1912, Burkill 37622 ( K); Serpo stream, Nov. 1911 – Mar. 1912, Burkill 36323 (n.v.); Under Rotung, Nov. 1911 – Mar. 1912, Burkill 36138 (n.v.); Yambung Camp, Nov. 1911 – Mar. 1912, Burkill 36025 (n.v.); Yambung River, Nov. 1911 – Mar. 1912, Burkill 37755 (n.v.). Assam: Charduar forest, Apr. 1887, Mann ( K); Lakhimpur District, 17 Apr. 1885, Clarke 37917A ( K). Nagaland: Naga Hills, 2 Nov. 1856, Griffith, herb no. 2569 ( K 000634628); ibid., Nov. 1856, Griffith, herb no. 2569 ( K 000634627 ).

Description

Rhizomatous, dioecious herb, 40–60 cm high.Rhizome: 10–15 mm wide, tomentose.Stipules:lanceolate, 10–20 × 4–5 mm, sparsely puberulous on reverse, persistent. Leaves: petiole 14–57 cm long, densely red villose which are longer near leaf base, up to 3 mm long; lamina ovate to broadly ovate, basifixed, base cordate with lobes not overlapping, 10 –33 × 7–21 cm, asymmetric, upper surface green, sparsely red pilose, underside green, red pilose all over, longer on veins, venation palmate, midrib 8–19 cm long; margin entire to repand, with hairs; apex acute or shortly acuminate. Inflorescence: cymose, terminal, few; peduncle with red pubescence, male peduncle branching twice, primary 1–6(–10) cm long, secondary 1–5 mm long, 4 –5 flowers; female peduncle unbranching, 5–15 cm long, 1(–2) flowers; bracts ovate-orbicular, 10–13 × 8–10 mm, glabrous, caduceus. Male flower: pedicel up to 15 mm long, red pubescence; tepals 4; outer tepals ovate-orbicular, 17– 21 × 12 –13 mm, white to pink, tomentose on reverse near base, margin entire; inner tepals narrowly obovate or spathulate, 13–18 × 5–12 mm, white to pink, glabrous; androecium with 70–100 stamens, symmetric; filaments 3 mm long, equal, free; anther oblong elliptic, 2–3 mm long, dehiscing through slits running nearly the entire length of the anther, not hooded, connective extended. Female flower: pedicel up to 20 mm long, red pubescence; bracteoles absent; tepals 4–6, equal, ovate, outer tepals 2, 15–20 × 8–12 mm, white to pink, tomentose on reverse near base, margin entire, inner tepals 2–4, smaller yet glabrous; ovary 3–4-locular, placentae bifid; capsule globose, red pubescence, without wings; styles 3–4, convoluted with ends slightly twisted, deciduous. Fruit: on stout pedicel, erect, capsule elliptic to globose, 8–20 × 9–15 mm, red pubescence.

Distribution and phenology

Arunachal-Pradesh, North Assam and Nagaland; 300–1200 m. Flowering: November to January; fruiting: November to April.

Conservation status

Least Concern. The calculated range of B. aborensis is small (AOO is 48 km 2 and EOO is 14,497 km 2), which would suggest a status of vulnerable. However this likely reflects the lack of collections throughout the mountains of Arunachal-Pradesh and those of Nagaland, where there appears to be large areas of suitable habitat. The species is also found in the Moulling National Park.

Remarks

Begonia aborensis is very similar to B. silletensis ; the main difference being the longer indumentum on the former. Begonia aborensis has dense red hairs, 2–5 mm in length on the petioles and leaf undersides, whereas B. silletensis has short dense curled hairs giving a velvety appearance. The male flowers of B. aborensis are on a slender pubescent peduncle that is rarely over 10 cm long and hence shorter than the petioles; in B. silletensis the peduncles are sturdier, up to 25 cm long and glabrous. Begonia aborensis is described as dioecious, however, further observations would be valuable. See also notes under B. silletensis .

One of the syntypes (Burkill 36682, K) is not listed here as the specimen is not B. aborensis . It appears to belong to Begonia sect. Parvibegonia and probably represents a new species. The material is not sufficient to furnish a description, however.

Figures

Fig. 5. Map showing the location of B. aborensis Dunn specimens.