Lasianthus repoeuensis Pierre ex Pitard (1924: 387) .

Type:— CAMBODIA. Montibus Knang Krepoeu, May 1870, L. Pierre 1257 (holotype A00096531 image!, isotypes P02285238, P3981160, images!). Figure 5

Specimen examined:— LAOS. Attapeu Province, Sanamxai Diostrict, Bolaven Plateau, in lowland evergreen forest, 14°48′19″N, 106°26′39″E, 223 m elev., 6 July 2019, P. Souladeth et al. L3067 (FOF, KAG, TNS) .

Distribution:— Cambodia, Laos, Thailand, Vietnam.

Vernacular name:— [(Xangsan Speu, “Xangsan” means Lasianthus in general in Lao and “Speu” refers to “Knang Krepoeu”, the type locality of this species, which is currently known as Kampong Speu Province), proposed here].

Notes:— Lasianthus repoeuensis is distinguished from the other Lasianthus species in Laos by having lamina oblong-elliptic, elliptic-obovate, 9–17 × 2.8–4.3 cm, glabrous, adaxially blackish brown when dry, with 14–16 pairs of secondary veins, and stipule broadly triangular, 4–5 mm long.