| Noun | 1. | subclass Rosidae - a group of trees and shrubs and herbs mostly with polypetalous flowers; contains 108 families including Rosaceae; Crassulaceae; Myrtaceae; Melastomaceae; Euphorbiaceae; Umbelliferae class - (biology) a taxonomic group containing one or more orders rosid dicot family - a family of dicotyledonous plants rosid dicot genus - a genus of dicotyledonous plants class Dicotyledonae, class Dicotyledones, class Magnoliopsida, Dicotyledonae, Dicotyledones, Magnoliopsida - 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 order Umbellales, Umbellales - plants having umbels or corymbs of uniovulate flowers; includes the Umbelliferae (chiefly herbs) and Cornaceae (chiefly trees or shrubs) Myrtales, order Myrtales, order Thymelaeales, Thymelaeales - Myrtaceae; Combretaceae; Elaeagnaceae; Haloragidaceae; Melastomaceae; Lecythidaceae; Lythraceae; Rhizophoraceae; Onagraceae; Lecythidaceae; Punicaceae order Rosales, Rosales - in some classifications this category does not include Leguminosae Geraniales, order Geraniales - an order of plants of subclass Rosidae including geraniums and many other plants; see Euphorbiaceae; Geraniaceae; Rutaceae; Malpighiaceae; Simaroubaceae; Meliaceae; Zygophyllaceae; Tropaeolaceae |