Flora of North America North of Mexico Volume 13: Magnoliophyta: Geraniaceae to Apiaceae includes treatments prepared by 60 authors covering 624 species in 147 genera classified in 14 families. Apiaceae, the carrot or parsley family, is by far the largest family in the volume with 403 species, and includes many economically important plants that are used for food, spices, medicine, and ornamentals, as well as some species that are notoriously toxic. Many species are narrow endemics, a significant number of which have been described only recently. The treatment brings together the latest taxonomic and phylogenetic information on this diverse family. Some other families in the volume that have significant numbers of species include Anacardiaceae, Araliaceae, Geraniaceae, Rutaceae, and Sapindaceae. Descriptions for all families, genera, species, and infraspecies are provided, as are occurrence maps for all species and infraspecies. Every genus and 30% of the species are illustrated. Keys are included to aid in the identification of taxa at all ranks. Volume 13 is the twenty-fifth volume to be published in the planned 30-volume Flora of North America North of Mexico series.