Lasianthus honbaensis V. S. Dang, Tagane

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.Published as part of Dang, Van-Son & Naiki, Akiyo, 2023, A revision of the genus Lasianthus Jack (Rubiaceae) from Vietnam, pp. 1921-1935 in Phytotaxa 581 (1) on pages 1921-1935, DOI: 10.11646/phytotaxa.581.1.1, http://zenodo.org/record/757155