We recorded 156 taxa of legumes, comprising 50 genera, 152 species, and 34 infra-specific taxa, in the southern part of state of Nuevo León. Genera with the highest numbers of species were Dalea (19), Desmodium (12), Acacia (10), Astragalus (10), Phaseolus (8), Mimosa (8), Lupinus (7), and Senna (6). The growth forms were herbaceous species (49% of species), shrubby species (33%), twining and climbing species (16%), and arboreal species (2%). The highest numbers of taxa were in oak-pine forest (95), coniferous forest (excluding Pinus cembroides) (93), oak forest (59), and Pinus cembroides forest (56). Based on legume distribution in different plant communities, 3 distributional patterns were recognized: 1) shrublands and halophytic grasslands; 2) oak, oak-pine, coniferous (other than Pinus cembroides), and Pinus cemborides forests and piedmont scrub; and 3) subalpine prairie.