Lasianthus oblongilobus H. Zhu 2002

54. Lasianthus oblongilobus H.Zhu (2002: 400) — Fig. 82 (plate), Fig. 78 (map) Type: — VIETNAM. Khanh Hoa Province, Khanh Son District, 1500–1600 m elev., 22 April 1997, Averyanov L., Nguyen Q.B., Nguyen T.H. VH 4153 (holotype AAU!). Specimens examined: — VIETNAM. Central: Lam Dong Province, Bidoup National Park, 1655 m elev., 19 November 2014, Toyama H., Tagane S., Dang V.S., Nagamasu H., Naiki A., Tran H., Yang C.J. V1923 (FU, VNM); in the same location, 1658 m elev., 26 November 2017, Dang V.S. & Naiki A. N10109 (VNM, the herbarium of Iriomote Station (Japan)); Khanh Hoa Province, Hon Ba Nature Reserve, 30 km west of Nha Trang City, 1518 m elev., 24 July 2018, Dang V.S. & Hoang N.T.B.N., Dang 194 (VNM). Distribution: —Endemic to Vietnam (currently known as Khanh Son District and Hon Ba Nature Reserve of Khanh Hoa Province and Biduoup Nui Ba National Park of Lam Dong Province). Habitat & Ecology: —Growing under the canopy of an evergreen forest or the edge of a montane forest at 1200– 1700 m elev. Phenology: —Flowering and fruiting from July to December. Vernacular name: —Xú hưƠng đài thuôn. Notes: — Lasianthus oblongilobus was described as new from a Vietnamese specimen by Zhu (2002). This is characterized by having elliptic-lanceolate leaves, secondary veins 5–6 on each side of midrib, calyx lobes oblong and 1.5–2 mm long. Additional fruit morphology for L. oblongilobus: fruits globose, 4–5 mm diam., smooth, glabrous, crowned by calyx lobes, yellowish-orange when ripe; pyrenes 4. Seed ovoid, 2–3 mm long, irregular sulcate on the abaxial face, blackish brown when dry.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