13. Raphiocarpus clemensiae (Pellegr.) B.L.Burtt in Weber & Burtt (1998: 173), Nguyen & Wen (2018: 1424), Vu (2018: 56)

≡ Didissandra clemensiae Pellegrin (1930: 511), Ho (2000: 16), Phuong (2005: 241).

Type: — VIETNAM. Da Nang: Mount Bani in the main coast range about 25 kilometers from Tourane, May–July, 1927, J. & M.S.Clemens 4154 (holotype P04060143 photo!) .

Distribution:—The species is endemic to Vietnam found in Da Nang City Area and provinces Thua Thien Hue, Quang Nam, and Kon Tum.

Ecology and phenology:—It grows in humid evergreen broad-leaved montane forests on granite and shale at elevations of 1000–1600 m a.s.l. Flowers in February–July, September–December.

Conservation status:—The species area comprises Da Nang environs and territories of Thua Thien Hue, Quang Nam, and Kon Tum provinces, with a total square of about 25 000 km2. The species is quite dependent on its submontane and montane habitats, which are now severely threatened by deforestation. Despite several presently confirmed locations, the species should be tentatively classified as Near Threatened under IUCN (2023) guidelines.

Additional specimens examined:— VIETNAM. Thua Thien Hue: Hue, Nui Bach Ma Mt., 1500 m, 8 September 1938, M.Poilane 27681 (P photo); the same locality, 10 December 1940, M.Poilane 31090 (P photo); Bach Ma Mt., 700 m, 13 July 1943, J.E.Vidal 810A (P photo) ; Quang Nam: pres du village Ploi de Go-Oi, 24 February 1941, M.Poilane 31583 (P photo), 31610 (P photo); Village de Mang Tra, 26 February 1941, M.Poilane 31766 (P photo); Village de Moi de Mang, 26 February 1941, M.Poilane 31826 (P photo) ; Kon Tum: W slope of Ngoc Linh Mt., 1600 m, 15 March 1995, L.Averyanov et al. VH 760 (HN, LE, P photo) .