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| Begonia nangunheensis Y.M. Shui & W.H. Chen, in Guo, Chen, ... et Shui, 2021. |
Abstract
Begonia nangunheensis belonging to Begonia sect. Platycentrum is described and illustrated as a new species in Caryota obtusa forests in Yunnan province of China. It is similar to Begonia siamensis in 3-winged fruits, 2-loculed ovary and axile placentation with 2 segments per locule, but differs in its glabrous petiole and abaxial leaf-blade, ovate outer tepals and oblanceolate to narrowly obovate inner tepals of staminate flower, and the unequal pistillate tepals. The new species is assigned to Critically Endangered according to the guidelines of IUCN Red List Categories and Criteria (version 13).
Keywords: Begonia sect. Platycentrum, Begonia siamensis, Southwestern China, Thailand, Eudicots
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| Begonia nangunheensis Y.M. Shui & W.H. Chen, sp. nov. A. Habit; B. Male flower; C. FemaleFlower; D. The middle section of ovary; E. Fruit. Scale bar: A=4 cm, B–E=1 cm. All based on the holotype. (Drawn by Ling Wang) |
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| Flowers and fruits of Begonia nangunheensis Y.M. Shui & W.H. Chen, sp. nov. A. Inflorescence with flowers and fruits; B. Pistillate flowers: different view; C. Inflorescence: staminate and pistillate flowers and fruit: lateral view; D. Staminate and pistillate flowers; E. Staminate flower and fruit; F. Pistillate flower, lateral view; G. Staminate flower, back view; H. Face view of staminate flower; I. Front view of androecium; J. Face view of pistillate flower; K. Style; L. Pistillate flower, styles and fruit; M. Middle cross section of ovary. Scale bar: A-G, J, L = 2 cm, H & M= 1 cm, I & K = 2 mm. A-L. Photographed by Jin-Chao Zhao, M by Luo-Yan Li. |
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| Habitat and morphology of Begonia nangunheensis Y.M. Shui & W.H. Chen, sp. nov. A. Habitat: Caryota obtusa forest; B. Habitat: cliff; C. Whole plant and inflorescence; D. Leaf and young inflorescence; E. Whole plant and rhizome; F. Leaf: adaxial surface; G. Leaf: abaxial surface. Scale bar: C-D = 5 cm, E = 8 cm, F-G = 4 cm. A-E. Photographed by Jin-Chao Zhao, F and G by Yu-Min Shui. |
Begonia nangunheensis Y.M. Shui & W.H. Chen, sp. nov.
The new species is most similar to Begonia siamensis Gagnepain in 3-winged fruits, 2-loculed ovary and axile placentation with 2 segments per locule, but differs in its petiole glabrous (vs. dense brown pubescent in B. siamensis)and leaf blade abaxially glabrous ( vs. dense brown pubescent), ovate and 2.0–2.3 × 1.3–1.6 cm (vs. broadly-ovate to orbicular and 1–1.5 × 1–1.2 cm) outer tepals and oblanceolate to narrowly obovate (vs. oblong) inner tepals of staminate flower, and the unequal (vs. nearly equal size) pistillate tepals.
Etymology: The epithet ‘nangunheensis’ refers to the type locality: Nangunhe National Natural Reserve.
Shi-Wei Guo, Wen-Hong Chen, Aung Aung, Sirilak Radbouchoom, Jin-Chao Zhao, Zhi Hong Li and Yu-Min Shui. 2021. Begonia nangunheensis, A New Species of Begoniaceae from Yunnan province, China. Phytotaxa. 480(2); 201–209. DOI: 10.11646/phytotaxa.480.2.9
