comprising seed plants that produce an embryo with paired cotyledons and net-veined leaves; divided into six (not always well distinguished) subclasses (or superorders): Magnoliidae and Hamamelidae (considered primitive), Caryophyllidae (an early and distinctive offshoot), and three more or less advanced groups: Dilleniidae, Rosidae, Asteridae | a group of trees and shrubs and herbs mostly with polypetalous flowers; contains 108 families including Rosaceae, Crassulaceae, Myrtaceae, Melastomaceae, Euphorbiaceae, Umbelliferae |