Lasianthus khanhvinhensis V.S.Dang & Naiki (2021: 20)

Dang, Van-Son & Naiki, Akiyo, 2023, A revision of the genus Lasianthus Jack (Rubiaceae) from Vietnam, Phytotaxa 581 (1), pp. 1921-1935 : 1921-1935

37. Lasianthus khanhvinhensis V.S.Dang & Naiki (2021: 20) — Fig. 61 (plate), Fig. 62 (map)

Type: — VIETNAM. Khanh Hoa Province, Hon Ba Nature Reserve, 1336 m elev., 26 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. V2261 (holotype VNM! [ VNM00042904 ]; isotypes FU!, VNM! [ VNM00042905 , VNM00042906 ], the herbarium of Iriomote Station (Japan)) .

Specimens examined: — VIETNAM. Central: Khanh Hoa Province, Hon Ba Nature Reserve, 1336 m elev., 12°07’14.42’’N, 108°57’25.76’’E, in evergreen forests, 26 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. V2261 ( FU, VNM, the herbarium of Iriomote Station (Japan )) .

Distribution: —Endemic to Vietnam (known only from the Hon Ba Nature Reserve, Khanh Hoa Province).

Habitat & Ecology: —Primary forest and secondary forest at 700–1500 m elev.

Phenology: —Flowering and fruiting from March to July.

Vernacular name: —Xú hưƠng khánh vĩnh.

Notes: — Lasianthus khanhvinhensis is morphologically similar to L. clementis Merr. (1908: 164) , which is distributed in Cambodia, Philippines, Indonesia, and New Guinea, but differs from the latter in having leaf size (7–11 × 2–3 cm vs. 7–10 × 3–5 cm), bracts 0.5–1 mm long (vs. absent), larger calyx tube (1.5–2 mm long vs. 1.5 mm long) and orange fruits (vs. blue).

Figures

FIGURE 61. Lasianthus khanhvinhensis V.S.Dang & Naiki (from V2261, VNM): A. Branch with fruits, B. Close-up of expanding young leaves, C. Stipules, D. Abaxial leaf surfaces, E–F. Inflorescence showing side view calyxes, G–H. Fruits, J. Seeds (A, F, G–H: photos by Shuichiro Tagane).

FIGURE 62. Distribution maps of Lasianthus khanhvinhensis, L. konchurangensis, L. kontumensis and L. lacduongensis.