Calliandra ricoana, a new species of Leguminosae (Mimosoideae, tribe Ingeae),from the state of Chiapas, Mexico is described and illustrated. Critical examination of C. ricoana in comparison with members of Calliandra section Androcallis, series Macrophyllae shows that it is morphologically similar and presumably closely related to C. macqueenii and C. trinervia var. arborea, but it can be distinguished from these and the other members of the series by a combination of characters, namely the arborescent habit, the relatively larger leaflets, the short peduncles, the homomorphic flowers, the longer corollas and the longer, exserted staminal tubes.