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| Begonia subfiliformis D.K.Tian & J.Y.Zhou, in Zhou, Guan, Yan, Tao et Tian, 2025. 拟丝形秋海棠 || taiwania.ntu.edu.tw/abstract/2084 |
Abstract
Begonia subfiliformis is a new species of Begonia section Coelocentrum found in the karst region of southwest Guangxi, China. It has yellowish-green flowers and glandular inflorescences. Morphologically, it is similar to B. filiformis, but differs mainly by larger stipules with hairy or nearly glabrous dorsal ridge, adaxial leaves sparsely short-hispid and adorned with whitish-green patches or ring-shaped belt, larger basal bracts, larger staminate flower and tepals, and more stamens. Due to the current data, the new species is assigned to Endangered (EN) according to Guidelines for Using IUCN Red List Categories and Criteria.
Keyword: Begonia daxinensis, Begonia filiformis, Begonia sect. Coelocentrum, karst region, new taxon, Southwest Guangxi
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| Morphology of Begonia subfiliformis D.K.Tian & J.Y.Zhou. A. Leaves showing diversity in variegation patterns of two sides; B. Rhizome with grayish-white villous; C. Leaf sections showing adaxial and abaxial indumentums; D. Petiole section; E & F. Inflorescences; G. Young inflorescence with bracts; H. Pedicel with red glandular villous; I. Front (left), back (middle) and side (right) views of staminate flower; J & K. Front (left) and side (right) views of pistillate flower; L. Top view of androecium; M. Top view of stigmas; N & O. Stipules showing hairy or nearly glabrous dorsal ridge and margin; P. Bracts; Q. Side view of young fruit. (Photos by Jinye Zhou) |
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| Begonia subfiliformis D.K.Tian & J.Y.Zhou. A–C. Habitat and habit, photographed in Tiandeng, China; D. Wild plant, photographed in Tiandeng, China; E. Cultivated plants. (Photos by Jinye Zhou) |
Begonia subfiliformis D.K.Tian & J.Y.Zhou sp. nov.
拟丝形秋海棠
Diagnosis: Begonia subfiliformis is mostly similar to B. filiformis Irmsch., but differs mainly by its larger stipules 7–24 × 5–18 mm (vs. 5–10 × 5–7 mm) with hairy or nearly glabrous (vs. hairy) dorsal ridge, adaxial leaf sparsely short-hispid (vs. densely villous) and adorned with whitish-green patches or ring-shaped belt (vs. radial patches or spots), abaxial leaf densely villous or villoushirsute only along veins (vs. densely villous whole back), stout and upright inflorescences (vs. delicate and drooping), larger basal bracts 4–12 × 3–8 mm (vs. 4–7 × 1.1–1.5 mm), larger staminate flowers 16–35 × 10–25 mm (vs. 20–25 × 10–15 mm) (Table 1) (Gu et al., 2007; Ku, 2006). In addition, it is similar to B. daxinensis T.C.Ku and B. morsei Irmsch. in leaf shape and texture, but can be easily distinguished from B. daxinensis by indumentums of petiole and abaxial leaf, flower color, androecium shape, number of stamens and capsule indumentum (Table 1) (Wu and Ku, 1997; Gu et al., 2007), and distinguished from B. morsei by leaf size, peduncle length, flower number and color, pedicel and tepal indumentum and phenology (Gu et al., 2007).
Etymology: The specific epithet “subfiliformis” refers to its similarity to B. filiformis, because the two are easily confused by extremely similar flowers. The Chinese name is given as “拟丝形秋海棠”.
Jinye Zhou, Shikai Guan, Haixia Yan, Dayan Tao and Daike Tian. 2025. Begonia subfiliformis, A New Species of Begonia（sect. Coelocentrum) from Guangxi of South China. Taiwania. 70(3); 377-381. DOI: 10.6165/tai.2025.70.377 taiwania.ntu.edu.tw/abstract/2084 [12 May 2025]