Begonia kingdon-wardii Tebbitt in Kew Bulletin 62: 143, 2007

Chen, Wen-Hong, Jin, Xiao-Hua & Shui, Yu-Min, 2018, Rediscovery and amended descriptions of Begonia kingdon-wardii (Begoniaceae) from North Myanmar, PhytoKeys 94, pp. 59-64 : 60-62

Begonia kingdon-wardii Tebbitt in Kew Bulletin 62: 143, 2007 Figs 1A , 2

Type.

Myanmar, Kachin Mts E of Fort Hertz, 27°20'N, 97°30'E, alt. 900 m, Aug. 1926, Kingdon-Ward 7341 (holotype, K000037101!; isotype, K000037102!) .

Handwriting annotation from the holotype specimens (Fig. 1B ): " Begonia ass. B. Balansaeanae Gagnep. almost aff.?. Flowers white. Leaves very dark green above, glossy, with a metallic lustre, purple nervation, margin crenated. On shady banks and rocks in the jungle. Whole plant glabrous. The contrast between the white flowers and the dark shining leaves amongst which they nestle is very striking".

Revised description.

Plants terrestrial, perennial; stems rhizomatous, 3-10 cm long, 0.2-0.4 cm diam., with fibrous roots on node and 0.5-0.8 cm long internode. Stipules caducous, lanceolate, 1.1-1.3 × 0.4-0.5 cm, margin entire, apex acuminate. Leaf alternate, pliciform, rotund, 10-16 cm diam., margin entire, symmetric on base, usually 4-7-palmatifid venation; adaxially glabrous and serpentinous, green lines and 3-5 spots along each main nerve, abaxially red and pubescent along the main nerves. Petiole 10-18 cm long, densely pubescent. Inflorescences axillary, cymose, dichasial, with separate male and female individuals; peduncles 3-5 cm long; bracts greenish, ovate, 8-9 × 3-4 mm, persistent during flowering. Bracteoles similar to and slightly smaller than bracts; petals white, glabrous on both sides. Male flower: petals 4; outer 2, ovate, 1.2-1.4 × 0.6-0.7 cm, inner 2, elliptic, 0.5-0.6 × 0.2-0.3 cm; androecium actinomorphic, 0.5-0.6 cm diam., filaments free below, anthers oblong, almost equal to the filaments, dehiscent with laterally and obliquely longitudinal slits, connective slightly extended and truncate on the top. Female flower: petals 2, broadly elliptic, 0.9-1 × 1.1-1.3 cm; ovary wingless, obtusely 3-hooked, 3-locular, placentation axial, placenta segments thick, 2 per locule, ovules present on both sides of placental branches; styles 3, forked twice, caducous in fruit, stigmas spiralled into a band. Fruit triangular berry-like, pendulous, with an in distinct beak. Flowering Oct. to Nov., Fruiting from the first of Nov. to Oct. of the next year.

Distribution.

Only seen in Kachin State, Myanmar.

Additional examined specimens.

Upper Burma (=Myanmar): Kachin Hills, 30 November, 1912, collect. Capt. & M. Joppin 4378 (K!); Myanmar, Kachin, Putao, on shaded banks and rocks, 27°20'N, 97°30'E, alt. 900 m, Dec. 10 1937, Kingdon-Ward 13569 (BM!); Myanmar, Kachin State, Putao, Wasadam village, alt. 860 m, 27°30'09"N, 97°11'45"E, near the stream in the Musa forests, occasional, Oct. 15, 2014, Putao Exped. 311 (KUN!, PE!); Myanmar, Kachin State, Putao, Wasadam village, alt. 900 m, 27°30'06"N, 97°11'44"E, along the moist slope in the Musa forests, occasional, Oct. 25, 2014, Putao Exped. 1230 (PE!).

Discussion.

In Begonia sect. Sphenanthera , Begonia kingdon-wardii is unique in the pliciform leaf and female flower with two tepals (Doorenbos et al. 1999; Shui et al. 2002). It is obviously different from Begonia burkillii Dunn in B. sect. Sphenanthera and B. rockii Irmsch. in B. sect. Platycentrum in the locules of ovary and leaf shape. Morphologically, this species is also similar to B. gulinqingensis S. H. Huang & Y. M. Shui ( Begonia sect. Diploclinium ) in the leaf shape, placentation and fruit shape, but different in its dioecious plant, pliciform leaf, female flower with two sepals and berry fruit. It is also similar to B. leprosa ( Begonia sect. Leprosae ) in the leaf shape, especially the texture of the leaf blade and B. zhengyiana Y. M. Shui ( Begonia sect. Coelocentrum ) in shape of the leaf blade and fruit.

The rediscovery of its living plants provides researchers an opportunity to explore its taxonomic description and horticultural value in North Myanmar. This species with very rare individuals is distributed in a restricted area in Northern Myanmar and grows in the very shady and dark places under the forests. Its flowers are near the ground under the leaves, so that this habit influences the pollination and fruit setting. Another important and interesting habit may be that the fruits need over one year to become mature as some species [ B. handelii Irmsch. and B. silletensis (A. DC.) C. B. Clarke] in Begonia sect. Sphenanthera . Besides, the pliciform leaf of the living plant is difficult to be observed on the holotype (Figs 1 , 2 ). Now, the rediscovery not only reveals the need to undertake more surveys in North Myanmar, but also fills the gap about the deficient data of the species indicated by Tebbitt (2007) and so can bring an amazing plant to mankind for research and horticultural use (Fig. 2 ).

Figures

Figure 1. Holotype of Begonia kingdon-wardii Tebbitt (A) and the annotation on the holotype specimens (B).

Figure 2. The images of Begonia kingdon-wardii Tebbitt (Putao Exped. 311 in PE and KUN) A Male plant B Male inflorescences C Face view of male flower D Female plant E Female inflorescences F Face view of female flower G Leaf blade adaxially H Leaf blade abaxially I Middle section of ovary in flower showing two placenta segments per locule J Inferior section of ovary in flower K Middle section of mature berry-like fruit showing thick placenta segments. Scale bars: A, D 10 cm B, E 1 cm C, F 1 cm G, H 4 cm I, J, K 1 cm. All photographed by Yu-Min Shui.