Lasianthus dienkhanhensis V.S.Dang & Naiki (1921: 40)

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

18. Lasianthus dienkhanhensis V.S.Dang & Naiki (1921: 40) — Fig. 38 (plate), Fig. 37 (map)

Type. VIETNAM. Khanh Hoa Province, Hon Ba Nature Reserve, 919 m elev., 21 February 2014, Toyama H., Dang V.S., Tagane S., Fuse K., Yahara T., Nagamasu H., Tran H. with Ngoc N.V., Cuong N.Q., Thach N.D., Hieu H.N.P. V 859 (holotype VNM! [ VNM00042885 ]; isotypes FU!, VNM! [ VNM00042886 , VNM00042887 ], the herbarium of Iriomote Station (Japan)) .

Specimens examined: — VIETNAM. Central: Khanh Hoa Province, Hon Ba Nature Reserve, 919 m elev., 12°06’46.88’’N, 108°58’14.43’’E, in evergreen forests, 21 February 2014, Toyama H., Dang V.S., Tagane S., Fuse K., Yahara T., Nagamasu H., Tran H. with Ngoc N.V., Cuong N.Q., Thach N.D., Hieu H.N.P. V 859 ( FU, VNM, the herbarium of Iriomote Station (Japan)); in the same location, 919 m elev., 12°06’46.88’’N, 108°58’14.43’’E, in evergreen forests, 19 July 2014, Tagane S., Kanemitsu H., Dang V.S., Tran H. with Hanh N., Loi X.N., Thach N.D., Dinh N., Hieu P.N.H. V 1709, V1710 ( FU, VNM, the herbarium of Iriomote Station (Japan )) .

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

Habitat & Ecology: —In shaded places of the primary and secondary forests at 900–1000 m elev.

Phenology: —Flowering and fruiting specimens from February to July.

Vernacular name: —Xú hưƠng diên khánh.

Notes: — Lasianthus dienkhanhensis is similar to L. chevalieri Pit. (1924: 384) based on leaf shape and fruit color, but differs from the latter in having shorter petioles (8–10 mm long vs. 10–15 mm long), larger stipules (4–5 mm long vs. ca. 3 mm long), bracts 8–14 mm long (vs. inconspicuous) and smaller calyx (2–3 mm long vs. 3–6 mm long for tubes, 8–9 mm long vs. 9–14 mm long for lobes).

Figures

FIGURE 37. Distribution maps of Lasianthus dalatensis, L. dienkhanhensis, L. eberhartii and L. elevatineurus.

FIGURE 38. Lasianthus dienkhanhensis V.S.Dang & Naiki (from V859, VNM): A. Branch with flower buds, B. Stipules, C. Abaxial leaf surfaces, D–F. Inflorescence showing lateral view buds and flower, G. Young fruits, H. Mature fruit, I. Seeds.