Lasianthus lecomtei Pit. (1924: 374)

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

45. Lasianthus lecomtei Pit. (1924: 374) — Fig. 71 (plate), Fig. 67 (map)

Type: — VIETNAM. Da Nang City , 18 November 1911, Lecomte & Finet 1316 (holotype P! [P02285240]) .

Specimens examined: — VIETNAM. Central: Lam Dong Province, Lac Duong District, 1700–1850 m elev., 15 March 1997, L. Averyanov, N. Q. Binh, N. V. Duy, P. K. Loc, VH2628 (P); Gia Lai Province, Kon Ka Kinh National Park, 1000–1200 m elev., 24 March 2021, Dang V.S., Truong B.V. & Le T.K.N., Dang 428 ( VNM); in the same location, Kon Ka Kinh National Park , 1320 m elev., 25 March 2021, Dang V.S. & Truong B.V., Dang 428bis ( VNM) .

Distribution: —Endemic to Vietnam (currently known as Da Nang City, Gia Lai Province, and Lam Dong Province).

Habitat & Ecology: —Growing under a canopy of the evergreen montane forest at 1000–1400 m elev. It is found in the natural habitats where dominated by species of Rubiaceae , Euphorbiaceae , Fagaceae , Fabaceae , Lauraceae , Sapindaceae , Phyllanthaceae , Ericaceae , Rutaceae , Meliaceae , and Symplocaceae .

Phenology: —Flowering and fruiting from February to September.

Vernacular name: —Xú hưƠng lecomte.

Notes: — Lasianthus lecomtei was described as new from a Vietnamese specimen by Pitard (Lecomte & Finet 1316). It is characterized by having ovate to oblong-lanceolate leaves, secondary veins 6–9 on each side of midrib, bracts linear and 7–10 mm long, calyx lobes 4, and fruits ellipsoid, pyrenes 4.

Lasianthus lecomtei is similar to L. schmidtii K.Schum. (1902: 340) (synonym: L. kerrii Craib [1911: 396] ) which was distributed in China, Thailand, and Vietnam, but differs from the latter in having ovate to oblong-lanceolate leaves (vs. oblong to elliptic-lanceolate), apex acuminate to caudate (vs. apex acuminate) and styles 8 mm long (vs. 3 mm long).

Figures

FIGURE 67. Distribution maps of Lasianthus lamdongensis, L. lancifolius, L. larsenii, L. latifolius and L. lecomtei.

FIGURE 71. Lasianthus lecomtei Pit. (from Dang 428, VNM): A. Branch, B. Close-up of expanding young leaves, C. Stipules, D. Abaxial leaf surfaces, E. Inflorescence showing lateral view calyx, D–H. Fruits.