The leaf anatomy of Chaetobromus Nees is described and illustrated. The genus has non-Kranz anatomy but with a low lateral cell count. The abaxial epidermis is not pooid as microhairs are present, the silica bodies are dumbbell-shaped and the stomatal subsidiaries are dome-shaped. From the sample of 33 randomly selected specimens from throughout the distribution range o f the genus it was possible to identify four anatomical groups, each associated with a specific habitat and differing in vegetative morphology. These intergrade in a reticulate pattern and do not constitute discrete entities. It appears that the genus is monospecific with four poorly separated subspecific taxa. Keywords: Chaetobromus, Danthonieae, leaf anatomy, Poaceae.