Lasianthus pierrei Pit. 1924

56. Lasianthus pierrei Pit. (1924: 386) — Fig. 85 (plate), Fig. 84 (map) Type: — VIETNAM. Ba Ria— Vung Tau, Con Dao District, October 1876, Harmand 6174 (holotype P! [P03981118]; isotype P! [P03981115]). Specimens examined: — VIETNAM. Central: Khanh Hoa Province, Hon Ba Nature Reserve, 900 m elev., 24 July 2018, Dang V.S. & Hoang N.T.B.N., Dang 195 (VNM); in the same location, 1502 m elev., 15 June 2019, Dang V.S. & Hoang N.T.B.N., Dang 345 (VNM, the herbarium of Iriomote Station (Japan)). Distribution: —Endemic to Vietnam (currently known as Con Dao National Park in Con Dao District of Ba Ria—Vung Tau Province and Hon Ba Nature Reserve of Khanh Hoa Province). Habitat & Ecology: —Growing under the shade of evergreen forest or on a hill of the forest at 500–1600 m elev. Phenology: —Flowering and fruiting from June to November. Vernacular name: —Xú hưƠng pierre. Notes: — Lasianthus pierrei was described in 1924 from a Vietnamese specimen (A. Harmand 6174). It is characterized in the field as having yellow-brown pubescent branches, linear-lanceolate leaves, secondary veins 4–6 on each side of midrib; petioles 4–5 mm long, flowers white, calyx tube longer than the lobes, and fruits globose with 4 pyrenes. Additional fruit morphology for L. pierrei: Fruit drupaceous, globose, 5–7 mm long, 4–5 mm in diam., sparsely strigose, crowned by persistent short calyx lobes; pyrenes 4. Seeds ovoid, 3–4 mm long, sulcate on the abaxial face, 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