Abstract: Anatomical studies on the petiole of eight indigofera species of the tribe galegeae common in eastern Nigeria were carried out with the aid of a light microscope. An analysis of the features of the internal arrangement of the petiole shows that these taxa possess vital characters that could be used in their description with a view of establishing taxonomic relationship among the species. The epidermal layer and collenchyma cells as well as crystal types are some of the characters assessed and discussed among the indigofera species investigated. The presence of uniseriate, tubular and closely parked epidermal cells in I. paniculata, I. stenophylla and I. terminalis is of taxonomic. The well-developed large distinct angular and lacuna collenchyma cells in I. prieureana, I. senegalensis and I. tinctoria are significant. Furthermore, the presences of variously shaped crystals and tannins in most of the species studied conforms the highly tanninferous nature of these taxa and hence the mechanical and storage roles of these crystal and tannins in plants.