Abstract
Two new species of Lasianthus (Rubiaceae), L. bolavenensis Tagane & Soulad., and L. laoticus Tagane, Soulad. & Nob.Tanaka from Bolaven Plateau, southern Laos, are described and illustrated, with their vernacular names and preliminary conservation status. In addition, L. repoeuensis Pierre ex Pit. is recorded in Laos for the first time.
References
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<p>Dang, V.S., Tagane, S., Toyama, H. & Tran, H. (2015) <em>Lasianthus yaharae</em> (Rubiaceae), a new species from Hon Ba Nature Reserve, southern Vietnam. <em>Annales Botanici Fennici</em> 52: 352–354. https://doi.org/10.5735/085.052.0513</p>
<p>Dang, V.S., Tagane, S., Toyama, H., Naiki, A., Nagamasu, H. & Yahara, T. (2016) <em>Lasianthus honbaensis</em> (Rubiaceae), a new species from southern Vietnam. <em>Annales Botanici Fennici </em>53: 263–266. https://doi.org/10.5735/085.053.0414</p>
<p>Dang, V.S. & Naiki, A. (2019) Two new species of <em>Lasianthus</em> (Rubiaceae) from Hoang Lien National Park, northern Vietnam. <em>Phytotaxa</em> 423 (1): 33–40. https://doi.org/10.11646/phytotaxa.423.1.4</p>
<p>Dang, V.S., Tagane, S., Hoang, N.S., Toyama, H. & Naiki, A. (2019) <em>Lasianthus bidoupensis</em> (Rubiaceae), a new species from southern Vietnam. <em>Annales Botanici Fennici </em>56: 191–195. https://doi.org/10.5735/085.056.0123</p>
<p>Dang, V.S. & Naiki, A. (2020) Two new species of <em>Lasianthus</em> (Rubiaceae) from northern Vietnam. <em>Annales Botanici Fennici</em> 57: 49–54. https://doi.org/10.5735/085.057.0106</p>
<p>IUCN (2012) <em>IUCN Red List Categories and Criteria</em>,<em> version 3.1</em>. Gland and Cambridge. Available from: http://www.iucnredlist.org (accessed 24 March 2021)</p>
<p>Naiki, A., Tagane, S., Chhang, P., Toyama, H., Zhu, H., Dang, V.S. & Yahara, T. (2015) Flora of Bokor National Park, Cambodia II: four new species and nine new records of <em>Lasianthus </em>(Rubiaceae) from Cambodia. <em>Acta Phytotaxonomica et Geobotanica</em> 66 (3): 153–179. https://doi.org/10.18942/apg.KJ00010115702</p>
<p>Napiroon, T., Balslev, H., Poopath, M., Chamchumroon, V., Vajrodaya, S. & Chayamarit, K. (2018) Three new taxa and a new record of <em>Lasianthus</em> (Rubiaceae) in Thailand. <em>Annales Botanici Fennici</em> 55 (4–6): 207–216. https://doi.org/10.5735/085.055.0402</p>
<p>Napiroon, T., Chayamarit, K., Dawson, S., Till, W. & Balsvlev, H. (2020) A synopsis of <em>Lasianthus</em> (Lasiantheae, Rubiaceae) in Thailand and two additional new species. <em>Phytotaxa</em> 439 (1): 1–38. https://doi.org/10.11646/phytotaxa.439.1.1</p>
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<p>Pitard, J. (1924) <em>Lasianthus</em> Jack. <em>In:</em> Lecomte, P.H., Humbert, H. & Gagnepain, F. (Eds.) <em>Flore générale de l’Indo-Chine</em> 3. Masson, Paris, pp. 371–399.</p>
<p>Souladeth, P., Tagane, S., Newman, M.F. & Prajaksood, A. (2020) Two new species of <em>Eriocaulon</em> (Eriocaulaceae) from Laos. <em>Kew Bulletin</em> 75: 56. https://doi.org/10.1007/s12225-020-09909-0</p>
<p>Tagane, S., Souladeth, P., Nagahama, A., Suyama, Y., Ishii, N., Tanaka, N. & Yahara, T. (2020) Twenty-five new species records in the flora of Laos. <em>Natural History Bulletin of the Siam Society</em> 64: 25–41.</p>
<p>Tagane, S., Souladeth, P., Kongxaysavath, D., Rueangruea, S., Suddee, S., Suyama, Y., Suzuki, E. & Yahara, T. (2020) Two new species and 20 new records for the flora of Laos. <em>Thai Forest Bulletin, Botany</em> 49 (1): 111–126. https://doi.org/10.20531/tfb.2021.49.1.14</p>
<p>Zhu, H. (2001) A taxonomic revision of the genus <em>Lasianthus</em> Jack (Rubiaceae) from Thailand. <em>Acta Phytotaxonomica Sinica </em>39: 116–150.</p>
<p>Zhu, H. & Taylor, C.M. (2011) <em>Lasianthus</em>. <em>In:</em> Wu, Z.Y., Raven, P.H. & Hong, D.Y. (Eds.) <em>Flora of China</em>, vol. 19. Science Press, Beijing, and Missouri Botanical Garden Press, St. Louis, pp. 185–198.</p>
<p>Zhu, H., Roos, M.C. & Ridsdale, C.E. (2012) A taxonomic revision of the Malesian species of <em>Lasianthus</em> (Rubiaceae). <em>Blumea</em> 57: 1–102. https://doi.org/10.3767/000651912X652012</p>
<p>Dang, V.S., Tagane, S., Toyama, H. & Tran, H. (2015) <em>Lasianthus yaharae</em> (Rubiaceae), a new species from Hon Ba Nature Reserve, southern Vietnam. <em>Annales Botanici Fennici</em> 52: 352–354. https://doi.org/10.5735/085.052.0513</p>
<p>Dang, V.S., Tagane, S., Toyama, H., Naiki, A., Nagamasu, H. & Yahara, T. (2016) <em>Lasianthus honbaensis</em> (Rubiaceae), a new species from southern Vietnam. <em>Annales Botanici Fennici </em>53: 263–266. https://doi.org/10.5735/085.053.0414</p>
<p>Dang, V.S. & Naiki, A. (2019) Two new species of <em>Lasianthus</em> (Rubiaceae) from Hoang Lien National Park, northern Vietnam. <em>Phytotaxa</em> 423 (1): 33–40. https://doi.org/10.11646/phytotaxa.423.1.4</p>
<p>Dang, V.S., Tagane, S., Hoang, N.S., Toyama, H. & Naiki, A. (2019) <em>Lasianthus bidoupensis</em> (Rubiaceae), a new species from southern Vietnam. <em>Annales Botanici Fennici </em>56: 191–195. https://doi.org/10.5735/085.056.0123</p>
<p>Dang, V.S. & Naiki, A. (2020) Two new species of <em>Lasianthus</em> (Rubiaceae) from northern Vietnam. <em>Annales Botanici Fennici</em> 57: 49–54. https://doi.org/10.5735/085.057.0106</p>
<p>IUCN (2012) <em>IUCN Red List Categories and Criteria</em>,<em> version 3.1</em>. Gland and Cambridge. Available from: http://www.iucnredlist.org (accessed 24 March 2021)</p>
<p>Naiki, A., Tagane, S., Chhang, P., Toyama, H., Zhu, H., Dang, V.S. & Yahara, T. (2015) Flora of Bokor National Park, Cambodia II: four new species and nine new records of <em>Lasianthus </em>(Rubiaceae) from Cambodia. <em>Acta Phytotaxonomica et Geobotanica</em> 66 (3): 153–179. https://doi.org/10.18942/apg.KJ00010115702</p>
<p>Napiroon, T., Balslev, H., Poopath, M., Chamchumroon, V., Vajrodaya, S. & Chayamarit, K. (2018) Three new taxa and a new record of <em>Lasianthus</em> (Rubiaceae) in Thailand. <em>Annales Botanici Fennici</em> 55 (4–6): 207–216. https://doi.org/10.5735/085.055.0402</p>
<p>Napiroon, T., Chayamarit, K., Dawson, S., Till, W. & Balsvlev, H. (2020) A synopsis of <em>Lasianthus</em> (Lasiantheae, Rubiaceae) in Thailand and two additional new species. <em>Phytotaxa</em> 439 (1): 1–38. https://doi.org/10.11646/phytotaxa.439.1.1</p>
<p>Parker, R. (1925) Decades Kewenses. Plantarum Novarum in Herbario Hortii Regii Conservatorum. <em>Kew Bulletin</em> 10: 426–433. https://doi.org/10.2307/4115104</p>
<p>Pham, H.H. (2000) <em>Cây cỏ Việt Nam: An illustrated flora of Vietnam</em>, <em>vol. 3</em>. Youth Publication, Ho Chi Minh City, pp. 202–209.</p>
<p>Pitard, J. (1924) <em>Lasianthus</em> Jack. <em>In:</em> Lecomte, P.H., Humbert, H. & Gagnepain, F. (Eds.) <em>Flore générale de l’Indo-Chine</em> 3. Masson, Paris, pp. 371–399.</p>
<p>Souladeth, P., Tagane, S., Newman, M.F. & Prajaksood, A. (2020) Two new species of <em>Eriocaulon</em> (Eriocaulaceae) from Laos. <em>Kew Bulletin</em> 75: 56. https://doi.org/10.1007/s12225-020-09909-0</p>
<p>Tagane, S., Souladeth, P., Nagahama, A., Suyama, Y., Ishii, N., Tanaka, N. & Yahara, T. (2020) Twenty-five new species records in the flora of Laos. <em>Natural History Bulletin of the Siam Society</em> 64: 25–41.</p>
<p>Tagane, S., Souladeth, P., Kongxaysavath, D., Rueangruea, S., Suddee, S., Suyama, Y., Suzuki, E. & Yahara, T. (2020) Two new species and 20 new records for the flora of Laos. <em>Thai Forest Bulletin, Botany</em> 49 (1): 111–126. https://doi.org/10.20531/tfb.2021.49.1.14</p>
<p>Zhu, H. (2001) A taxonomic revision of the genus <em>Lasianthus</em> Jack (Rubiaceae) from Thailand. <em>Acta Phytotaxonomica Sinica </em>39: 116–150.</p>
<p>Zhu, H. & Taylor, C.M. (2011) <em>Lasianthus</em>. <em>In:</em> Wu, Z.Y., Raven, P.H. & Hong, D.Y. (Eds.) <em>Flora of China</em>, vol. 19. Science Press, Beijing, and Missouri Botanical Garden Press, St. Louis, pp. 185–198.</p>
<p>Zhu, H., Roos, M.C. & Ridsdale, C.E. (2012) A taxonomic revision of the Malesian species of <em>Lasianthus</em> (Rubiaceae). <em>Blumea</em> 57: 1–102. https://doi.org/10.3767/000651912X652012</p>