11. Raphiocarpus sinovietnamicus Z.B.Xin, L.X.Yuan & T.V.Do in Xin et al. (2022: 2).

Type: — CHINA. Hainan: Baoting Li and Miao Autonomous County, Maogan Town, ca 526 m, 18°33′N 109°29′E, 8 November 2021, L.X.Yuan & Z.Y.Zhang, 20211118001 (holotype IBK, isotypes CSH, IBSC)

Distribution:—The species is found in Vietnam (Ha Tinh and Kon Tum provinces) and in SE China (Hainan Province).

Ecology and phenology:—It grows in evergreen broad-leaved lowland and submontane forests on granite and shale at elevations of 500–1200 m a.s.l. Flowers in August–November.

Conservation status:— The species is currently known from four populations found in SE China (Hainan) and Vietnam (Ha Tinh and Kon Tum provinces), with an area of occurrence of about 800 km 2 and an area of occupancy of less than 20 km 2. At the same time, anthropogenic factors, especially deforestation and agricultural extension, seriously affect species habitats in Vietnam. Given this situation, the species was recently assessed as Endangered (EN B1 ab(iii)+ B2 ab(iii)), following the IUCN criteria (Xin et al. 2022).

Additional specimens examined (paratypes):— VIETNAM. Ha Tinh: Vu Quang District, Vu Quang National Park, Sao La Forest Station, ca 520 m, 18°15.380′N 105°26.427′E, 30 August 2020, D.V.Truong DV T382 (IBK, VNMN) ; Kon Tum: Kon Plong District, Hieu Commune, Vi Chring Village, ca 1210 m, 14°64.620′N 108°45.094′E, 28 November 2019, D.Q.Diep, L.T. Hung, XH 45 (VNMN); the same locality, 8 Dec 2021, D.V.Truong DVT 328 (PHH, VNMN) .