1. a group of families of mostly flowers having basal or central placentation and trinucleate pollen (binucleate pollen is commoner in flowering plants); contains 14 families including: Caryophyllaceae (carnations and pinks); Aizoaceae; Amaranthaceae; Batidaceae; Chenopodiaceae; Cactaceae (order Opuntiales); Nyctaginaceae; Phytolaccaceae; corresponds approximately to order Caryophyllales; sometimes classified as a superorder