Lasianthus dakgleiensis V. S. Dang, Naiki & Tagane 1921

16. Lasianthus dakgleiensis V.S.Dang, Naiki & Tagane (1921: 36) — Fig. 35 (plate), Fig. 32 (map) Type: — VIETNAM. Kon Tum Province, Ngoc Linh Nature Reserve, 1376 m elev., 13 February 2017, Tagane S., Nagamasu H., Nguyen V.N., Hoang T.B., Hoang T.S., Yang C.J., Kawakubo A. V 6528 (holotype VNM! [VNM00042884]; isotypes DLU!, FU!, the herbarium of Iriomote Station (Japan)). Specimens examined: — VIETNAM. Central: Kon Tum Province, Ngoc Linh Nature Reserve, 1376 m elev., 15˚10’07.04”N, 107˚45’43.04’’E, 13 February 2017, Tagane S., Nagamasu H., Nguyen V.N., Hoang T.B., Hoang T.S., Yang C.J., Kawakubo A. V6528 (DLU, FU, VNM); in the same location, 1141 m elev., 15˚32’32.04”N, 107˚43’54.09’’E, 10 February 2017, Tagane S., Nagamasu H., Nguyen V.N., Hoang T.B., Hoang T.S., Yang C.J., Kawakubo A. V 6067 (DLU, FU, the herbarium of Iriomote Station (Japan)). Distribution: —Endemic to Vietnam (known only from the Ngoc Linh Nature Reserve, Kon Tum Province). Habitat & Ecology: —In the lower montane evergreen forest at 1000–1400 m elev. Phenology: —Flowering and fruiting from February to July. Vernacular name: —Xú hưƠng đắk glei. Notes: — Lasianthus dakgleiensis is similar to L. congesticymus H. Zhu (2000: 124) which is distributed in Thailand and Malaysia, but differs from the latter in having smaller leaves (7–11 × 2–3.5 cm vs. 12–19 × 3.5–6.5 cm), fewer secondary veins (4–5 on each side of midrib vs. 6–7 on each side of midrib), shorter petioles (4–5 mm long vs. 8–10 mm long), bracts 1 mm long (vs. absent), larger calyx lobes (2.5–3 mm long vs. 1 mm long) and fruits with 5 (vs. 4) pyrenes.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