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| Begonia mangdenensis T.S. Hoang & C.W. Lin, in Hoang, Lin & Vu, 2021. Thu hải đường Măng Đen || taiwania.ntu.edu.tw |
Abstract
A new species and record of Begonia L. from the central highlands is described and illustrated. The new species, B. mangdenensis is assignable to Begonia sect. Platycentrum based on the axillary inflorescence, 4-tepaled staminate flower and 5-tepaled pistillate flower with ovary two locules each with two placentas. B. mangdenensis is most similar to B. lamdongiana, but it is different in its variegated (vs. uniformly green) and velvetly (vs. slightly waxy) upper surface of lamina, villous (vs. glabrous) peduncle, first pair of bracts glabrous (vs. puberulous or hirsute) in abaxial surface, bracts margin entire and ciliate (vs. denticulate or laciniate to biserrate, ciliate). In addition, B. yui Irmsch., previously known from China, is newly recorded from Vietnam.
Keyword: Begonia mangdenensis, Begonia lamdongiana, Begonia yui, endemism, Platycentrum, Tubibracteolea
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| Begonia mangdenensis T.S. Hoang & C.W. Lin. A. Habit; B, B'. Portion of leaf, upper and lower surfaces; C. Stipules; D, D', D''. Bracts; E, E'. Staminate flower, face and side views; F, F', F''. Stamens, ventral, dorsal and side views; G, G'. Pistillate flower, face and side views; H, H'. Style and stigmatic band, dorsal and ventral views; I. Capsule; J. Cross section of an immature capsule. |
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| Begonia mangdenensis T.S. Hoang & C.W. Lin. A. Habit and habitats; B. Leaf, upper and lower surface; C. Rhizome, showing stipules and petioles; D, E. Portion of leaf, upper and lower surfaces; F. Distal part of petiole, showing villous; G. Inflorescence, showing bracts; H. Staminate flower, face and back views; I. Pistillate flower, face and side views; J. Cross section of an immature capsule; K. Capsule. |
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| Begonia mangdenensis T.S. Hoang & C.W. Lin. (A–E). A. Portion of leaf, B. Leaves, showing strongly velvety, subglabrous adaxial surface, and veins strongly sunken, C. Showing very sparsely puberulous on upper surface; D. Stipules, showing entire margin; E. Bracts, showing, showing sparsely ciliate margin. Begonia lamdongiana C.W.Lin, T.C.Hsu & Luu. (F–I). F. Portion of leaf, showing slightly waxy and scabrous adaxial surface, and veins slightly prominent; G. Habit; H. Stipules, showing ciliate margin; I. Bracts, showing biserrate and ciliate margin. |
Begonia mangdenensis T.S. Hoang & C.W. Lin, sp. nov.
Diagnosis: Similar to Begonia lamdongiana C.W.
Lin, T.C. Hsu & Luu in its habit and lanceolate laminae,
4-tepaled staminate flower and 5-tepaled pistillate flower,
glabrous ovary. However, B. mangdenensis is different in
having maculation (vs. uniformly green) leaves adaxial
surface velvety (vs. slightly waxy), veins strongly sunken
(vs. slightly prominent) adaxially and glabrous (vs.
puberulous or hirsute in the first pair) bracts.
Etymology: The specific epithet refers to Mang Den
in Mang Den Commune, Kon Plong District, Kon Tum
Province, Central Highlands, Vietnam, where the new
species was found.
Vietnamese name: Thu hải đường Măng Đen.
Thanh Son Hoang, Che-Wei Lin and Anh Tai Vu. 2021. A New Species and Record for the Genus Begonia (Begoniaceae) from Vietnam. Taiwania. 66(3); 317-325. DOI: 10.6165/tai.2021.66.317
