Daniellia (Leguminosae: Caesalpinioideae) is a genus of ten species of medium to large trees from tropical and subtropical Africa. In contrast to earlier accounts, D. mortehanii is treated here as a synonym of D. pymertii, and D. oblonga, which previously has been treated by some authors as a synonym of D. thurifera, is accepted. In addition, we describe as new Daniellia glandulosa. Quantitative characters such as receptacle length, petiole width, sepal length, and largest leaflet length have been used to aid species differentiation following the results of recent morphometric studies that revealed their taxonomic utility. Micromorphological features such as pollen surface and leaf glands were studied in all species, many for the first time, and the number, position, and shape of the glands present in the leaves are shown to be taxonomically useful in distinguishing species. A dichotomous key and a table of key characters is provided, as well as detailed descriptions and distribution maps for each species. All species are illustrated, D. oblonga and D. glandulosa for the first time. Three lectotypes and a neotype are designated.