A revision of the genus Lasianthus Jack (Rubiaceae) from Vietnam Author Dang, Van-Son 0000-0001-8681-4141 Iriomote Station, Tropical Biosphere Research Center, University of the Ryukyus, 870 Uehara, Taketomi-cho, Yaeyama-gun, Okinawa, 907 - 1541 Japan. & Institute of Tropical Biology, Vietnam Academy of Science and Technology, 85 Tran Quoc Toan Street, District 3, Ho Chi Minh City, Vietnam. & Graduate University of Science and Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Ha Noi, Vietnam. & dvsonitb @ gmail. com; https: // orcid. org / 0000 - 0001 - 8681 - 4141 dvsonitb@gmail.com Author Naiki, Akiyo 0000-0002-3235-2823 Iriomote Station, Tropical Biosphere Research Center, University of the Ryukyus, 870 Uehara, Taketomi-cho, Yaeyama-gun, Okinawa, 907 - 1541 Japan. & Iriomote Station, Tropical Biosphere Research Center, University of the Ryukyus, 870 Uehara, Taketomi-cho, Yaeyama-gun, Okinawa, 907 - 1541 Japan. & naiki @ lab. u-ryukyu. ac. jp; https: // orcid. org / 0000 - 0002 - 3235 - 2823 * Author for correspondence naiki@lab.u-ryukyu.ac.jp text Phytotaxa 2023 2023-01-26 581 1 1921 1935 http://dx.doi.org/10.1094/PDIS-04-22-0755-PDN journal article 10.11646/phytotaxa.581.1.1 1179-3163 7571550 31. Lasianthus honbaensis V.S.Dang, Tagane & H. Toyama (2015: 263)— Fig. 54 (plate), Fig. 52 (map) Type: VIETNAM . Khanh Hoa Province , Hon Ba Nature Reserve , 30 km west of Nha Trang City , 1498 m elev., 18 July 2013 , Tagane S. , Yahara T .. Nagamasu H. , Fuse K. , Toyama H. , Tran H. , Son V.D. with Loi X.N. , Thach N.D. , Cuong Q.N. , Hieu P.N.H. , Thach K.N. V 275 ( holotype VNM ! [ VNM00042895 ]; isotypes FU !, KYO !, VNM ! [ VNM00042896 , VNM00042897 ]) . Specimens examined: VIETNAM . Central: Khanh Hoa Province , Hon Ba Nature Reserve, 30 km west of Nha Trang City, 1498 m elev., 18 July 2013 , Tagane S., Yahara T.. Nagamasu H., Fuse K., Toyama H., Tran H., Son V.D. with Loi X.N., Thach N.D., Cuong Q.N., Hieu P.N.H., Thach K.N. V275a ( VNM ); in the same location, 1524 m elev., 28 November 2017 , Dang V.S. & Naiki A. N10118 ( VNM ); in the same location, 1500 m elev., 23 July 2018 , Dang V.S. & Hoang N.T.B.N., Dang 191 ( VNM , the herbarium of Iriomote Station (Japan)); Lam Dong Province , Bidoup Nui Ba National Park, 50 km northeast of Dalat City, 1490 m elev., 19 November 2014 , Toyama H., Tagane S., Dang V.S., Nagamasu H., Naiki A., Tran H., Yang C.J. V1924 ( FU , VNM ). Distribution: —Endemic to Vietnam (currently known as Hon Ba Nature Reserve of Khanh Hoa Province and Bidoup Nui Ba National Park of Lam Dong Province ). Habitat & Ecology: —Growing under secondary and primary montane forests at 1200–1600 m elev. Phenology: —Flowering and fruiting from July to December. Vernacular name: —Xú hưƠng hòn bà. Notes: Lasianthus honbaensis was described as new from a Vietnamese specimen by Dang et al. (2015) . It is characterized in having densely appressed pubescent branches, leaf blade coriaceous, secondary veins 6–7 on each side of midrib, flowers white, and fruits orange when ripe.