2. Raphiocarpus sinicus Chun (1946: 275), Nguyen & Wen (2018: 1424), Vu (2018: 45)

Didissandra sinica (Chun) Wang (1975: 97), Phuong & Xuen (2010: 60), Wang et al. (1998: 281).

Lectotype (designated by Weber & Burtt 1998: 175): CHINA. Guangxi: Shi-Wan-Ta Shan, Na-Chin-Hsu, Pa-Shi-I, 800 m, 2 August 1933, C.L.Tso 23509 (IBSC, isolectotype NY01287879, photo!).

Distribution:—It is found in Vietnam (Lang Son Province) and in SE China (Guangxi and Guangdong provinces).

Ecology and phenology:—It grows in evergreen broad-leaved lowland forests and scrub on sandstone and shale at elevations of about 1000 m a.s.l. Flowers in August–September.

Conservation status:— The species is known from Guangxi and Guangdong provinces of SE China and Lang Son Province of N Vietnam, forming a narrow triangle with an approximate square of about 15000 km 2. Since there is no current data on the size of recorded populations or conditions of their habitats, the conservation status may be estimated as Data Deficient according to IUCN criteria (2023).

Additional specimens examined:— VIETNAM. Lang Son: Bac Son District, near the border with China, Le Kim Bien 8051 (HN ) . CHINA. Guangdong: Fangchanggang, Kung P’ing, and Vicinity T’aan Faan, 25–30 August 1936, W . T. Tsang 26725 (P); the same locality, 10–18 September 1936, W . T. Tsang 26847 (P); Sup Man Ta Shan, 21 July 1937, H . Y. Liang 69820 (A).