In the context of producing a revised phylogenetic Linnean taxonomy of angraecoid orchids, the mono-typic and narrow-endemic genus Ossiculum is synonymised with Calyptrochilum. Accordingly, a new combination in Calyptrochilum is proposed for Ossiculum aurantiacum. The morphological and DNA-based evidence for this transfer is discussed. Moreover, Calyptrochilum aurantiacum is here firstly reported outside Cameroon, with a record from the Republic of the Congo. The Red List conservation status of this species is reassessed and it is to be downgraded from "Critically Endangered" (CR) to "Endangered" (EN), following the recent discovery of additional subpopulations in Cameroon. Résumé En vue de produire une classification taxonomique linnéenne des orchidées angraecoïdes, le genre mono-typique Ossiculum, longtemps considéré comme endémique du sud-ouest Cameroun, est placé en synon-ymie de Calyptrochilum. En conséquence, une nouvelle combinaison dans Calyptrochilum est proposée pour Ossiculum aurantiacum. Les données morphologiques et moléculaires qui justifient cette combinaison sont PhytoKeys 98: 85-97 (2018)