Abstract
Begonia tuanii from Lao Cai Province of Vietnam is described and illustrated. The habit of B. tuanii is mostly similar with B. fordii, but it can be distinguished by its bracts glabrous (vs. pilose) abaxial surface, larger outer tepals of staminate flower by 25–40 × 24–35 mm (vs. 6–8 × 5–77 mm) that are whole glabrous (vs. abaxially hairy), inner ones 20–35 × 10–20 mm (vs. 5.6–7.5 × 3–4 mm) and glabrous (vs. pilose) ovary. Referring to the IUCN of Nature criteria, B. tuanii is proposed to be Endangered (EN D).
References
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">De Candolle, A. (1859) Mémoire sur la famille des Bégoniacées. <em>Annales des Sciences Naturelles Botanique, Ser. 4.</em> 11: 93–149.</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Do, T.V., Shui, Y.M., Le, P.V., Huynh, H.T.T., Kuznetsov, A.N., Kuznetsova, S.P. & Nuraliev, M.S. (2021) <em>Begonia xuansonensis</em>, a new orange-flowered species of Begoniaceae from northern Vietnam. <em>Phytotaxa</em> 510 (3): 251–262. https://doi.org/10.11646/phytotaxa.510.3.5</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Hoang, T.S., Lin, C.W. & Vu, A.T. (2021) A new species and record for the genus <em>Begonia</em> (Begoniaceae) from Vietnam. <em>Taiwania</em> 66 (3): 317–325. https://dx.doi.org/10.6165/tai.2021.66.317</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Hoang, T.S. & Lin, C.W. (2021) Two new species of <em>Begonia</em> (sect. <em>Platycentrum</em>, Begoniaceae) from the Central Highlands of Vietnam: <em>B. villosula</em> and <em>B. lophura.</em> <em>Phytotaxa</em> 510 (3): 263–274. https://doi.org/10.11646/phytotaxa.510.3.6</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Hu, C.M., Wu, C.Y. & Ku, T.C. (1995) <em>Begonia wenshanensis</em> C.M.Hu <em>ex</em> C.Y.Wu & T.C.Ku. <em>Acta Phytotaxonomica Sinica</em> 33 (3): 262–263.</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Hughes, M., Moonlight, P.W., Jara, A. &. Pullan, M. (2015) <em>Begonia</em> Resource Centre. Available from: http://padme.rbge.org.uk/begonia (accessed 15 April 2022)</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Irmscher, E. (1939) Die Begoniaceen Chinas und ihre Bedeutung fur die Frage der Formbildung in polymorphen Sippen. <em>Mitteilungen aus dem Institut für allgemeine Botanik in Hamburg</em> 10: 431–557.</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">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 26 January 2022)</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">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 <em>Begonia </em>from Guangxi, China. <em>Botanical Studies </em>61: 21. https://doi.org/10.1186/s40529-020-00298-y</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Pham, V.T., Trinh, N.B., Phan, K.L. & Lin, C.W. (2019) Two new species, <em>Begonia dinhdui</em> and <em>B.</em> <em>bacmeensis</em> (Begoniaceae), from Vietnam. <em>Phytotaxa</em> 427 (1): 22–30. https://doi.org/10.11646/phytotaxa.427.1.3</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Shui, Y.M., Chen, W.H., Peng, H., Huang, S.H. & Liu, Z.W. (2019) Taxonomy of Begonias. Yunnan Science and Technology Press, Kunming. 468 pp.</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Tian, D.K., Ge, B.J., Xiao, Y. & Li, C. (2021) <em>Begonia scorpiuroloba</em>, a new species in <em>Begonia </em>sect. <em>Platycentrum</em> (Begoniaceae) from southern Guangxi of China. <em>Phytotaxa</em> 479 (2): 191–197. https://doi.org/10.11646/phytotaxa.479.2.5</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Trin, N.B., Pham, T.T., Nguyen, V.D. & Pham, V.T. (2021) A new recorded species <em>Begonia wenshanensis</em> C.M.Hu <em>ex</em> C.Y.Wu & T.C.Ku (Begoniaceae) for the flora of Vietnam. <em>TNU Journal of Science and Technology</em> 226 (14): 67–72. https://doi.org/10.34238/tnu-jst.4703</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Wu, C.Y. & T.C. Ku (1995) New taxa of the <em>Begonia</em> L. (Begoniaceae) from China. <em>Acta Phytotaxonomica Sinica </em>33 (3): 251–280.</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Do, T.V., Shui, Y.M., Le, P.V., Huynh, H.T.T., Kuznetsov, A.N., Kuznetsova, S.P. & Nuraliev, M.S. (2021) <em>Begonia xuansonensis</em>, a new orange-flowered species of Begoniaceae from northern Vietnam. <em>Phytotaxa</em> 510 (3): 251–262. https://doi.org/10.11646/phytotaxa.510.3.5</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Hoang, T.S., Lin, C.W. & Vu, A.T. (2021) A new species and record for the genus <em>Begonia</em> (Begoniaceae) from Vietnam. <em>Taiwania</em> 66 (3): 317–325. https://dx.doi.org/10.6165/tai.2021.66.317</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Hoang, T.S. & Lin, C.W. (2021) Two new species of <em>Begonia</em> (sect. <em>Platycentrum</em>, Begoniaceae) from the Central Highlands of Vietnam: <em>B. villosula</em> and <em>B. lophura.</em> <em>Phytotaxa</em> 510 (3): 263–274. https://doi.org/10.11646/phytotaxa.510.3.6</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Hu, C.M., Wu, C.Y. & Ku, T.C. (1995) <em>Begonia wenshanensis</em> C.M.Hu <em>ex</em> C.Y.Wu & T.C.Ku. <em>Acta Phytotaxonomica Sinica</em> 33 (3): 262–263.</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Hughes, M., Moonlight, P.W., Jara, A. &. Pullan, M. (2015) <em>Begonia</em> Resource Centre. Available from: http://padme.rbge.org.uk/begonia (accessed 15 April 2022)</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Irmscher, E. (1939) Die Begoniaceen Chinas und ihre Bedeutung fur die Frage der Formbildung in polymorphen Sippen. <em>Mitteilungen aus dem Institut für allgemeine Botanik in Hamburg</em> 10: 431–557.</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">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 26 January 2022)</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">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 <em>Begonia </em>from Guangxi, China. <em>Botanical Studies </em>61: 21. https://doi.org/10.1186/s40529-020-00298-y</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Pham, V.T., Trinh, N.B., Phan, K.L. & Lin, C.W. (2019) Two new species, <em>Begonia dinhdui</em> and <em>B.</em> <em>bacmeensis</em> (Begoniaceae), from Vietnam. <em>Phytotaxa</em> 427 (1): 22–30. https://doi.org/10.11646/phytotaxa.427.1.3</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Shui, Y.M., Chen, W.H., Peng, H., Huang, S.H. & Liu, Z.W. (2019) Taxonomy of Begonias. Yunnan Science and Technology Press, Kunming. 468 pp.</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Tian, D.K., Ge, B.J., Xiao, Y. & Li, C. (2021) <em>Begonia scorpiuroloba</em>, a new species in <em>Begonia </em>sect. <em>Platycentrum</em> (Begoniaceae) from southern Guangxi of China. <em>Phytotaxa</em> 479 (2): 191–197. https://doi.org/10.11646/phytotaxa.479.2.5</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Trin, N.B., Pham, T.T., Nguyen, V.D. & Pham, V.T. (2021) A new recorded species <em>Begonia wenshanensis</em> C.M.Hu <em>ex</em> C.Y.Wu & T.C.Ku (Begoniaceae) for the flora of Vietnam. <em>TNU Journal of Science and Technology</em> 226 (14): 67–72. https://doi.org/10.34238/tnu-jst.4703</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Wu, C.Y. & T.C. Ku (1995) New taxa of the <em>Begonia</em> L. (Begoniaceae) from China. <em>Acta Phytotaxonomica Sinica </em>33 (3): 251–280.</span></span></span></p>