There are two species of Mayaca recorded from Ecuador, and one more is assumed to occur there. There are three species of Xyris recorded from Ecuador, and four more species of Xyris and one of Abolboda are assumed to occur there. There are two genera of Rapateaceae recorded from Ecuador, Epidryos (1 sp.) and Rapatea (2 spp.). Keys, descriptions, and specimen citations are provided for all taxa, and most species are illustrated.