Ornithoboea brachycarpa C.Xiong, F.Wen & Y.G.Wei, a new cave-dwelling species discovered in Guangxi, China, is described and illustrated. It is morphologically distinctive within the genus by its stamens bearing a beard on the sterile projection, a character not observed in any other known species of Ornithoboea. Phylogenetic analysis of ITS and trnL-F sequences places it as sister to O. feddei (H.Lév.) B.L.Burtt. Currently, only one population comprising approximately 150–200 mature individuals has been confirmed at the type locality. According to the IUCN Red List Categories and Criteria, it is provisionally assessed as Endangered (EN D).