Abstract
Begonia sect. Coelocentrum is a highly diverse section of the genus (87 species) with a Sino-Vietnamese distribution. A new species, Begonia wiformis, is described and illustrated herein, it is characterized by its rhizomes that send out elongated stolons, subglabrous lamina with a velvety texture adaxially, bracts with a denticulate margin, and a zygomorphic androecium. Additionally, Begonia filiformis, a species previously known only from China, is reported for the first time in Vietnam.
References
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<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span lang="en-GB">Tu, W.H., Wang, B.M., Huang, Y., Yao, G., Huang, J.X. & Li, Y.L. (2020)</span><span lang="en-GB"><em> Begonia guangdongensis</em></span><span lang="en-GB">, a new species of </span><span lang="en-GB"><em>Begonia </em></span><span lang="en-GB">(Begoniaceae) from Guangdong, China. </span><span lang="en-GB"><em>Phytokeys</em></span><span lang="en-GB"> 162: 29–36. https://doi.org/10.3897/phytokeys.162.51913</span></span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span lang="en-GB">Wu, C.Y. & Ku, T.C. (1995) New taxa of the </span><span lang="en-GB"><em>Begonia </em></span><span lang="en-GB">L. (Begoniaceae) from China. </span><span lang="en-GB"><em>Acta Phytotaxonomica Sinica </em></span><span lang="en-GB">33 (3): 251–280.</span></span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span lang="en-GB">Liu, Y., Tseng, Y.H., Yang, H.A., Hu, A.Q., Xu, W.B., Lin, C.W., Kono, Y., Chang, C.C., Peng, C.-I & Chung, K.F. (2020) Six new species of </span><span lang="en-GB"><em>Begonia</em></span><span lang="en-GB"> from Guangxi, China. </span><span lang="en-GB"><em>Botanical Studies</em></span><span lang="en-GB"> 61: e21. https://doi.org/10.1186/s40529-020-00298-y</span></span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span lang="en-GB">Chen, W.H., Radbouchoom, S., Nguyen, H.Q., Nguyen, H.T., Nguyen, K.S. & Shui, Y.M. (2018) Seven new species of</span><span lang="en-GB"><em> Begonia</em></span><span lang="en-GB"> (Begoniaceae) in Northern Vietnam and Southern China. </span><span lang="en-GB"><em>Phytokeys</em></span><span lang="en-GB"> 94: 65–85. https://doi.org/10.3897/phytokeys.94.23248</span></span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span lang="en-GB">Chung, K.F., Leong, W.C., Rubite, R.R., Repin, R., Kiew, R., Liu, Y. & Peng, C.-I</span><span lang="en-GB"><strong> (</strong></span><span lang="en-GB">2014) Phylogenetic analyses of </span><span lang="en-GB"><em>Begonia</em></span><span lang="en-GB"> sect. </span><span lang="en-GB"><em>Coelocentrum</em></span><span lang="en-GB"> and allied limestone species of China shed light on the evolution of Sino-Vietnamese karst flora. </span><span lang="en-GB"><em>Botanical Studies</em></span><span lang="en-GB"> 55: e1. https://doi.org/10.1186/1999-3110-55-1</span></span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span lang="en-GB">Hughes, M., Moonlight, P.W., Jara, A. &. Pullan, M. (2015) </span><span lang="en-GB"><em>Begonia</em></span><span lang="en-GB"> Resource Centre. Available from: http://padme.rbge.org.uk/begonia (accessed 6 December 2022)</span></span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span lang="en-GB">IUCN Standards and Petitions Subcommittee (2019) Guidelines for Using the IUCN Red List Categories and Criteria, Version 14. Prepared by the Standards and Petitions Subcommittee. Available from: https://www.iucnredlist.org/resources/redlistguidelines (accessed 27 August 2022)</span></span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span lang="en-GB">Peng, C.-I, Lin, C.W., Yang, H.A., Kono, Y. & Nguyen, H.Q.</span> <span lang="en-GB">(2015) Six new species of </span><span lang="en-GB"><em>Begonia</em></span><span lang="en-GB"> (Begoniaceae) from limestone areas in Northern Vietnam. </span><span lang="en-GB"><em>Botanical Studies</em></span> <span lang="en-GB">56: e9. https://doi.org/10.1186/s40529-015-0089-3</span></span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span lang="en-GB">Pham, V.T., Dinh, Q.D., Nguyen, V.C., Trinh, N.B., Nguyen, D.D., Nguyen, T.H. & Lin, C.W.</span> <span lang="en-GB">(2021) </span><span lang="en-GB"><em>Begonia</em></span><span lang="en-GB"> of Vietnam: an updated checklist, including a new species and a new record.</span><span lang="en-GB"><em> Phytotaxa</em></span><span lang="en-GB"> 507 (2): 144–154. https://doi.org/10.11646/phytotaxa.507.2.2</span></span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span lang="en-GB">Radbouchoom, S., Chen, W.H., Guo, S.W., Nguyen, H.Q., Nguyen, S.K., Nguyen, H.T. & Shui, Y.M.</span> <span lang="en-GB">(2019) Two new peltate-leaved species of</span><span lang="en-GB"><em> Begonia</em></span><span lang="en-GB"> L. (Begoniaceae) from northern Vietnam.</span><span lang="en-GB"><em> Phytotaxa</em></span> <span lang="en-GB">407 (1): 71–78. https://doi.org/10.11646/phytotaxa.407.1.10</span></span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span lang="en-GB">Shui, Y.M., Chen, W.H., Peng, H., Huang, S.H. & Liu, Z.W. (2019) </span><span lang="en-GB"><em>Taxonomy of Begonias.</em></span><span lang="en-GB"> Yunnan Science and Technology Press, Kunming. 468 pp.</span></span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span lang="en-GB">Tong, Y., Tian, D.K., Shu, J.P., Xiao, Y., Wang, B.M. & Fu, N.F.</span><span lang="en-GB"><strong> (</strong></span><span lang="en-GB">2019) </span><span lang="en-GB"><em>Begonia yizhouensis</em></span><span lang="en-GB">, a new species in </span><span lang="en-GB"><em>Begonia</em></span><span lang="en-GB"> sect.</span><span lang="en-GB"><em> Coelocentrum</em></span><span lang="en-GB"> (Begoniaceae) from Guangxi, China. </span><span lang="en-GB"><em>Phytotaxa</em></span><span lang="en-GB"> 407 (1): 59–70. https://doi.org/10.11646/phytotaxa.407.1.9</span></span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span lang="en-GB">Tu, W.H., Wang, B.M., Huang, Y., Yao, G., Huang, J.X. & Li, Y.L. (2020)</span><span lang="en-GB"><em> Begonia guangdongensis</em></span><span lang="en-GB">, a new species of </span><span lang="en-GB"><em>Begonia </em></span><span lang="en-GB">(Begoniaceae) from Guangdong, China. </span><span lang="en-GB"><em>Phytokeys</em></span><span lang="en-GB"> 162: 29–36. https://doi.org/10.3897/phytokeys.162.51913</span></span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span lang="en-GB">Wu, C.Y. & Ku, T.C. (1995) New taxa of the </span><span lang="en-GB"><em>Begonia </em></span><span lang="en-GB">L. (Begoniaceae) from China. </span><span lang="en-GB"><em>Acta Phytotaxonomica Sinica </em></span><span lang="en-GB">33 (3): 251–280.</span></span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;"><span lang="en-GB">Liu, Y., Tseng, Y.H., Yang, H.A., Hu, A.Q., Xu, W.B., Lin, C.W., Kono, Y., Chang, C.C., Peng, C.-I & Chung, K.F. (2020) Six new species of </span><span lang="en-GB"><em>Begonia</em></span><span lang="en-GB"> from Guangxi, China. </span><span lang="en-GB"><em>Botanical Studies</em></span><span lang="en-GB"> 61: e21. https://doi.org/10.1186/s40529-020-00298-y</span></span></span></span></p>