Lasianthus foetidissimus A.Chev. ex Pit. (1924: 395)

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

22. Lasianthus foetidissimus A.Chev. ex Pit. (1924: 395) — Fig. 43 (plate), Fig. 42 (map)

Type: — VIETNAM. Khanh Hoa Province, Hon Ba Nature Reserve , 1200–1500 m elev., 3 April 1918, A. Chevalier 38778 (holotype P! [P03980391]; isotype P!) .

Specimens examined: — VIETNAM. Central: Khanh Hoa Province, Hon Ba Nature Reserve, 1300 m elev., 13 July 2014, Tagane S., Kanemitsu H., Dang V.S., Tran H. with Loi X.N., Thach N.D., Hieu P.N.H. V1778 ( FU, VNM); in the same location, 1000 m elev., 22 July 2018, Dang V.S. & Hoang N.T.B.N., Dang 190 ( VNM); in the same location, 1502 m elev., 15 June 2019, Dang V.S. & Hoang N.T.B.N., Dang 343 ( VNM, the herbarium of Iriomote Station (Japan)); Lam Dong Province, Lac Duong District , 1500 m elev., 15 April 1997, L. Averyanov, N. Q. Binh, P. K. Loc, VH3979 (P); in the same location, Bidoup Nui Ba National Park , 50 km northeast of Dalat City , 1490 m elev., 19 November 2014, Toyama H., Tagane S., Dang V.S., Nagamasu H., Naiki A., Tran H., Yang C.J. V1956 ( FU, VNM, the herbarium of Iriomote Station (Japan)) .

Distribution: —Endemic to Vietnam (currently known as Hon Ba Nature Reserve of Khanh Hoa Province and Bidoup Nui Ba National Park of Lam Dong Province).

Habitat & Ecology: —Growing in secondary and primary forests, on the edge of the forest, at 700–1500 m elev.

Phenology: —Flowering and fruiting from June to December.

Vernacular name: —Xú hưƠng hôi.

Notes: — Lasianthus foetidissimus is similar to L. fasipanensis V.S. Dang & Naiki (2019: 34) which was discovered at Hoang Lien National Park of northern Vietnam by Dang & Naiki (2019), based on its pedunculate congested cymes and flower color at anthesis, but differs in its acute or slightly rounded leaf base (vs. oblique to obtuse), longer petioles (9–12 mm long vs. 6–10 mm long), smaller calyx (1.25 mm long vs. 1.5–2 mm long for tubes and 0.25 mm long vs. 0.8–1 mm long lobes), yellow to yellowish orange fruits (vs. blue) and fruits with 5 pyrenes (vs. 4 pyrenes).

Figures

FIGURE 42. Distribution maps of Lasianthus fansipanensis, L. foetidissimus, L. fordii and L. formosensis.

FIGURE 43. Lasianthus foetidissimus A.Chev. ex Pit. (from Dang 343, VNM and the herbarium of Iriomote Station (Japan)): A. Branch with flowers and bubs, B. Stipules, C. Abaxial leaf surfaces, D–E. Inflorescence showing side view buds and flower, F. Flower, G. Flower buds and fruit, H. Young fruits, I. Mature fruits.