Abstract
Begonia ngocbonii, a new species from North Vietnam is here described and illustrated. It resembles B. pellionioides Y.M.Shui & W.H.Chen, but is distinguishable by its hairy (vs. glabrous) stem, shorter inflorescence up to 1 cm (vs. ca. 5 cm or longer), 2-tepaled staminate and pistillate flowers (vs. 4-tepaled staminate flowers and 5-tepaled pistillate flowers), glabrous tepals (vs. spiny pilose on abaxial surface of outer tepals) and unilamellate placenta (vs. bilamellate).
References
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<p>IUCN Standards and Petitions Subcommittee (2019) <em>Guidelines for Using the IUCN Red List Categories and Criteria</em>, Version 14. Prepared by the Standards and Petitions Subcommittee. [https://www.iucnredlist.org/resources/redlistguidelines]</p>
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<p>Lin, C.W., Phan, L.C.S. & Nguyen, N.H. (2021b) <em>Begonia rigidifolia </em>ssp.<em> sonhungii</em> (sect. <em>Petermannia</em>, Begoniaceae), a new subspecies from limestone hills in Central Vietnam. <em>Phytotaxa</em> 498 (2): 139–144. https://dx.doi.org/10.11646/phytotaxa.427.1.3</p>
<p>Moonlight, P.W., Ardi, W.H., Padilla, L.A., Chung, K.-F., Fuller, D., Girmansyah, D., Hollands, R., Jara-Muñoz, A., Kiew, R., Leong, W.-C., Liu, Y., Mahardika, A., Marasinghe, L.D.K., O’Connor, M., Peng, C.-I, Pérez, A.J., Phutthai, T., Pullan, M., Rajbhandary, S., Reynel, C., Rubite, R.R., Sang, J., Scherberich, D., Shui, Y.-M., Tebbitt, M.C., Thomas, D.C., Wilson, H.P., Zaini, N.H. & Hughes, M. (2018) Dividing and conquering the fastest-growing genus: Towards a natural sectional classification of the mega-diverse genus <em>Begonia</em> (Begoniaceae). <em>Taxon </em>67: 267–323. https://doi.org/10.12705/672.3</p>
<p>Pham, V.T., Trinh, N.B., Phan, K.L. & Lin, C.W. (2019) Two new species, <em>Begonia dinhdui </em>and <em>B. bacmeensis</em> (Begoniaceae), from Vietnam. <em>Phytotaxa </em>427 (1): 22–30. https://dx.doi.org/10.11646/phytotaxa.427.1.3</p>
<p>Pham, V.T., Dinh, Q.D., Nguyen, V.C., Trinh, N.B., Nguyen, D.D., Nguyen, T.H. & Lin, C.W. (2021) <em>Begonia</em> of Vietnam: an updated checklist, including a new species and a new record. <em>Phytotaxa</em>. 507 (2): 144–154. https://doi.org/10.11646/phytotaxa.507.2.2</p>
<p>Radbouchoom, S., Chen, W.H., Guo, S.W., Nguyen, H.Q., Nguyen, S.K., Nguyen, H.T. & Shui, Y.M. (2019) Two new peltate-leaved species of <em>Begonia</em> L. (Begoniaceae) from northern Vietnam. <em>Phytotaxa</em> 407 (1): 71–78. https://dx.doi.org/10.11646/phytotaxa.407.1.10</p>
<p>Shui, Y.M., Chen, W.H., Peng, H., Huang, S.H. & Liu, Z.W. (2019a) Taxonomy of Begonias. Yunnan Science and Technology Press, Kunming. 468 pp.</p>
<p>Shui, Y.M., Vu, C.T., Le, T.A., Pham, T.T.D., Nguyen, V.D., Duong, T.M.H. & Lei, L.G. (2019b) Two new cane-like species of <em>Begonia </em>L. (Begoniaceae) from central Vietnam. <em>Phytotaxa</em> 411 (1): 57–64. https://doi.org/10.11646/phytotaxa.411.1.5</p>
<p>Souvannakhoummane, K., Hughes, M. & Lanorsavanh, S. (2016) <em>Begonia lamxayiana</em> Souvann. (Begoniaceae): a new species from Laos. <em>Thai Journal of Botany</em> 8 (1): 1–5.</p>
<p>Thomas, D.C., Hughes, M., Phutthai, T., Rajbhandary, S., Rubite, R., Ardi, W.H. & Richardson, J.E. (2011) A non-coding plastid DNA phylogeny of Asian <em>Begonia</em> (Begoniaceae): Evidence for morphological homoplasy and sectional polyphyly. <em>Molecular Phylogenetics and Evolution </em>60: 428–444. https://doi.org/10.1016/j.ympev.2011.05.006</p>
<p>Wang, J., Chen, W.H., Hughes, M., Yang, Z.Z. & Shui, Y.M. (2015) Additional Notes on the <em>Begonia </em>Sect. <em>Petermannia </em>(Begoniaceae) from China. <em>Plant Diversity and Resources</em> 37 (5): 563–568.</p>
<p>Hughes, M., Moonlight, P.W., Jara-Muñoz, A., Tebbitt, M.C., Wilson, H.P. & Pullan, M. (2015–Present) <em>Begonia</em> Resource Center. Online database available from: http://padme.rbge.org.uk/begonia/ (accessed 1 Mar 2022)</p>
<p>IUCN Standards and Petitions Subcommittee (2019) <em>Guidelines for Using the IUCN Red List Categories and Criteria</em>, Version 14. Prepared by the Standards and Petitions Subcommittee. [https://www.iucnredlist.org/resources/redlistguidelines]</p>
<p>Lin, C.W., Hsu, T.C., Luu, H.T., Nguyen, I.L.P.T., Yang, T.Y.A. & Li, C.W. (2021a) Revision of <em>Begonia</em> (Begoniaceae) in Bidoup-Nui Ba National Park, Southern Vietnam, including two new species. <em>Phytotaxa</em> 496 (1): 77–89. https://doi.org/10.11646/phytotaxa.496.1.4</p>
<p>Lin, C.W., Phan, L.C.S. & Nguyen, N.H. (2021b) <em>Begonia rigidifolia </em>ssp.<em> sonhungii</em> (sect. <em>Petermannia</em>, Begoniaceae), a new subspecies from limestone hills in Central Vietnam. <em>Phytotaxa</em> 498 (2): 139–144. https://dx.doi.org/10.11646/phytotaxa.427.1.3</p>
<p>Moonlight, P.W., Ardi, W.H., Padilla, L.A., Chung, K.-F., Fuller, D., Girmansyah, D., Hollands, R., Jara-Muñoz, A., Kiew, R., Leong, W.-C., Liu, Y., Mahardika, A., Marasinghe, L.D.K., O’Connor, M., Peng, C.-I, Pérez, A.J., Phutthai, T., Pullan, M., Rajbhandary, S., Reynel, C., Rubite, R.R., Sang, J., Scherberich, D., Shui, Y.-M., Tebbitt, M.C., Thomas, D.C., Wilson, H.P., Zaini, N.H. & Hughes, M. (2018) Dividing and conquering the fastest-growing genus: Towards a natural sectional classification of the mega-diverse genus <em>Begonia</em> (Begoniaceae). <em>Taxon </em>67: 267–323. https://doi.org/10.12705/672.3</p>
<p>Pham, V.T., Trinh, N.B., Phan, K.L. & Lin, C.W. (2019) Two new species, <em>Begonia dinhdui </em>and <em>B. bacmeensis</em> (Begoniaceae), from Vietnam. <em>Phytotaxa </em>427 (1): 22–30. https://dx.doi.org/10.11646/phytotaxa.427.1.3</p>
<p>Pham, V.T., Dinh, Q.D., Nguyen, V.C., Trinh, N.B., Nguyen, D.D., Nguyen, T.H. & Lin, C.W. (2021) <em>Begonia</em> of Vietnam: an updated checklist, including a new species and a new record. <em>Phytotaxa</em>. 507 (2): 144–154. https://doi.org/10.11646/phytotaxa.507.2.2</p>
<p>Radbouchoom, S., Chen, W.H., Guo, S.W., Nguyen, H.Q., Nguyen, S.K., Nguyen, H.T. & Shui, Y.M. (2019) Two new peltate-leaved species of <em>Begonia</em> L. (Begoniaceae) from northern Vietnam. <em>Phytotaxa</em> 407 (1): 71–78. https://dx.doi.org/10.11646/phytotaxa.407.1.10</p>
<p>Shui, Y.M., Chen, W.H., Peng, H., Huang, S.H. & Liu, Z.W. (2019a) Taxonomy of Begonias. Yunnan Science and Technology Press, Kunming. 468 pp.</p>
<p>Shui, Y.M., Vu, C.T., Le, T.A., Pham, T.T.D., Nguyen, V.D., Duong, T.M.H. & Lei, L.G. (2019b) Two new cane-like species of <em>Begonia </em>L. (Begoniaceae) from central Vietnam. <em>Phytotaxa</em> 411 (1): 57–64. https://doi.org/10.11646/phytotaxa.411.1.5</p>
<p>Souvannakhoummane, K., Hughes, M. & Lanorsavanh, S. (2016) <em>Begonia lamxayiana</em> Souvann. (Begoniaceae): a new species from Laos. <em>Thai Journal of Botany</em> 8 (1): 1–5.</p>
<p>Thomas, D.C., Hughes, M., Phutthai, T., Rajbhandary, S., Rubite, R., Ardi, W.H. & Richardson, J.E. (2011) A non-coding plastid DNA phylogeny of Asian <em>Begonia</em> (Begoniaceae): Evidence for morphological homoplasy and sectional polyphyly. <em>Molecular Phylogenetics and Evolution </em>60: 428–444. https://doi.org/10.1016/j.ympev.2011.05.006</p>
<p>Wang, J., Chen, W.H., Hughes, M., Yang, Z.Z. & Shui, Y.M. (2015) Additional Notes on the <em>Begonia </em>Sect. <em>Petermannia </em>(Begoniaceae) from China. <em>Plant Diversity and Resources</em> 37 (5): 563–568.</p>