Begonia (sect. Platycentrum) difformis W. C. Leong, C. I Peng & K. F. Chung 2015
Creators: name: Camfield, Rebecca
name: Hughes, Mark
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Cucurbitales
Begoniaceae
Begonia
Begonia difformis

description: Begonia difformis (Irmsch.) W.C.Leong, C.I Peng & K.F.Chung [sect. Platycentrum]
Fig. 21
Phytotaxa 227 (1): 86 (Leong et al. 2015). – Begonia lacinata Roxb. var. difformis Irmsch., Mitteilungen aus dem Institut für allgemeine Botanik in Hamburg 10: 531 (Irmscher 1939). – Begonia palmata D.Don var. difformis (Irmsch.) Golding & Kareg., Phytologia 54 (7): 495 (Golding & Karegeannes 1984).
– Type: China, Yunnan, Sep. 1912, Forrest 16098 (lecto-: E00299196, designated by Leong et al. 2015; isolecto-: K n.v.).
Other material examined
INDIA: Assam: Cachar, Boro Lakha, 1 May 1951, Koelz 27847 (MICH1225785). Manipur: Karong, 8 Oct. 1950, Koelz 26470 (MICH1225756). Meghalaya: Khasi Hills, Cherrapunji, 17 Apr. 1952, Chand 5380 (MICH1225702); ibid., 14 May 1952, Koelz 29907 (MICH1225690); ibid., 29 May 1952, Chand 5779 (MICH1225812); ibid., 2 Jun. 1952, Koelz 30159 (MICH1225720); ibid., 18 Jun. 1952, Koelz 30311 (MICH1225719); Mawphlang, 15 Jul. 1953, Koelz 33304 (MICH1225704); Pynursla, 3 Aug. 1949, Chand 2127 (MICH1225687); ibid., 5 Sep. 1949, Chand 2170 (MICH1225688); ibid., Koelz 23758 (MICH1225747).
Description
Rhizomatous, erect, monoecious herb, 20 –80 cm high. Rhizome: ca 2 cm wide, internodes 1–2.5 cm long. Stem: 10–20 mm wide, sparsely hirsute, internodes 5–15 cm long. Stipules: narrowly ovate or ovate, 30 × 20 mm, caduceus. Leaves: petiole 10–30 cm long, sparsely to densely hirsute, ovate or oblate-orbicular, base cordate, lobes not overlapping, 7–17 × 5–11 cm, asymmetric, upper surface green, hispidulous along veins, lower surface paler green, hirsute; venation palmate, midrib 5–14 cm long; margin shallowly denticulate, usually divided to ¼ of the blade or more, apex acuminate to longacuminate. Inflorescences: cymose, protandrous; axillary, few; peduncle red pubescent, branching 1–2 times, primary 10–15 cm long, secondary 1–2 cm long, with 3– 4 female and 3– 4 male flowers; bracts ovate, 10–15 × 5–8 mm, upper surface sparingly hispidulous to nearly glabrous, margin ciliate, caduceus. Male flowers: pedicel 10–20 mm long, densely red puberulous; tepals 4, outer tepals obovate to orbicular, 12–23 × 8–20 mm, white to pink, red setulose on reverse, margin entire, inner tepals oblanceolate to narrowly obovate, 10–23 × 5–10 mm, white, glabrous, entire; androecium with 80–200 stamens, symmetric; filaments 1–2.5 mm long, unequal, fused at base into short column; anther narrowly obovate, 2 mm long, dehiscing through slits, not hooded, connective extended, acute. Female flowers: pedicel 10–20 mm long, densely red puberulous; bracteoles absent; tepals 5, unequal, oblanceolate to orbicular, 8–24 × 4–21 mm, red setulose on reverse to almost glabrous, entire, inner tepals similar but smaller; ovary 2-locular, placentae bifid; capsule oblong-ellipsoid, 5–8 × 3–4 mm, very sparse to dense red setulose, with one long wing and two short rounded wings; styles 2, forked once and twisted, caduceus. Fruit: recurved, capsule obovoid, ca 1.5 × 1 cm, sparse red setulose to glabrous; wings extending along pedicel, unequal; longest wing obliquely oblong, 10–30 × 5–10 mm; shorter wings oblong, ca 5 × 10 mm.
Distribution and phenology
Assam, Meghalaya and Manipur; also in China and Myanmar. Flowering: June to October; fruiting: August to November.
Conservation status
Least Concern. The species has an EOO of 179,130 km 2 and an AOO of 108 km 2. The range of this recently described species could possibly be extended further, as it is likely more specimens will be found which are currently identified as the similar B. palmata. The specimens we have cited are split between Yunnan, China and the study area which are linked by the Arakan Mountains and the eastern end of the Himalayas, providing suitable habitat which is currently under-explored botanically.
Remarks
Begonia difformis is very similar to B. palmata but differs in having leaves with deeper lobes and with the hairs on the upper leaf surface being restricted to the veins (B. palmata has hairs all over). The most notable difference are the red setose hairs on the flowers and fruit; B. palmata has fine villose hairs. Also the largest wing of the fruit in B. difformis has a verrucose texture, unlike the smooth surface of the wings in the fruit of B. palmata. The description is augmented with information from the protologue.
description: Published as part of Camfield, Rebecca & Hughes, Mark, 2018, A revision and one new species of Begonia L. (Begoniaceae, Cucurbitales) in Northeast India, pp. 1-116 in European Journal of Taxonomy 396 on pages 33-34, DOI: 10.5852/ejt.2018.396, http://zenodo.org/record/3787049