This nomenclatural, taxonomic, and ecological treatment of 11 Central American obligate ant-acacias (Acacia allenii, A. chiapensis, A. collinsii, A. cookii, A. cornigera, A. gentlei, A. globulifera, A. hindsii, A. mayana, A. melanoceras, and A. sphaerocephala) and one quasi-obligate ant-acacia (Acacia ruddiae) is based on extensive field study from 1963 to 1972 and on herbarium specimens where of use. The population boundaries of all species are mapped and described with respect to ecological parameters. Morphological variation, details of the interaction with the ants, and acacia reproductive biology are presented for most species.
