Flora of North America North of Mexico Volume 10: Magnoliophyta: Proteaceae to Elaeagnaceae includes treatments prepared by 24 authors covering 454 species in 66 genera classified in 12 families. Onagraceae, the largest family in the volume, with 277 species in 17 genera, is especially richly represented in North America. The family comprises annual and perennial herbs, with some shrubs and a few small to medium-sized trees. Other families included in the volume are Buxaceae (3 species), Combretaceae (8 species), Elaeagnaceae (9 species), Gunneraceae (1 species), Haloragaceae (17 species), Lythraceae (31 species), Melastomataceae (15 species), Myrtaceae (38 species), Polygalaceae (53 species), Proteaceae (1 species), and Surianaceae (1 species). Descriptions for all of the families, genera, species, and recognized infraspecies are provided, as are occurrence maps for all species and infraspecies. Every genus and more than 25% of the species are illustrated. Keys are included to aid in the identification of genera in families and species within the genera. Volume 10 is the twenty-second volume to be published in the planned 30-volume Flora of North America North of Mexico series.