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 8. Lasianthus camlamensis V.S.Dang & Naiki (2021: 24) — Fig. 23 (plate), Fig. 20 (map) Type: — VIETNAM . Khanh Hoa Province , Hon Ba Nature Reserve , 25 November 2014 , Toyama H. , Tagane S. , Dang V.S. , Nagamasu H. , Naiki A. , Tran H. , Yang C.J. with Cuong N.Q. , Hieu H.N.P. V2161 ( holotype VNM ! [ VNM00042873 ]; isotypes FU !, VNM ! [ VNM00042874 , VNM00042875 ], the herbarium of Iriomote Station (Japan)) . Specimens examined: — VIETNAM . Central: Khanh Hoa Province , Hon Ba Nature Reserve , 1545 m elev., 12°07’01.82’’N , 108°56’43.63’’E , in evergreen forests, 25 November 2014 , Toyama H. , Tagane S. , Dang V.S. , Nagamasu H. , Naiki A. , Tran H. , Yang C.J. with Cuong N.Q. , Hieu H.N.P. V2161 ( VNM ); in the same location, 1500 m elev., 12°07’01.81’’N , 108°56’43.61’’E , in evergreen forests, 25 July 2018 , Dang V.S. , Dang 423bis ( VNM ) . Distribution: —Endemic to Vietnam (known only from the Hon Ba Nature Reserve, Khanh Hoa Province ). Habitat & Ecology: —Primary forest or on the edge of the forest at 1300–1578 m elev. Phenology: —Flowering and fruiting from April to July. Vernacular name. Xú hưƠng cam lâm. Notes: — Lasianthus camlamensis is similar to L. capitatus Blume (1827: 996) based on leaf shape, the number of secondary veins, and petioles size, but differs from the latter in having inflorescences sessile (vs. peduncles up to 2 cm long), bracts inconspicuous (vs. bracts 1 cm long), calyx lobes 5 (vs. 6), calyx size ( 2–2.5 mm long vs. 1–2 mm long for tubes and 3–4 mm long vs. up to 12 mm long for lobes) and fruits with 5 (vs. 6) pyrenes.