After completing a survey of its taxonomical history it can be concluded that the African genus Nemum Desv. ex Ham. (Cyperaceae) is a small natural genus within the tribe Abildgaardieae. The various species are characterised by the presence of persistent glumes, a rather unusual character in the Cyperaceae. These glumes, with their distinctive reddish brown colouring, leave the spikelet intact on the plant even long after flowering and fruiting. There are now 8 species distinguished within this genus. These species were thoroughly described and systematically discussed. The relationships between the various species were also brought into consideration. Moreover, this revision made it possible to create an identification key for the genus Nemum. While studying this genus it became evident that a species previously known as Scirpus angolensis C.B.Clarke can be included in Nemum as a new combination. Furthermore 3 new species can be recognised amongst the many specimens now present in the herbarium of the Ghent University. Also, two subspecies (Nemum spadiceum subsp. spadiceum and Nemum spadiceum subsp. spadolense) are distinguishable in Nemum spadiceum.