Most members are herbaceous, with woody species possessing anomalous secondary growth.
Adaptation to xeric environments with stem succulence and the evolution of C4 and CAM photosynthesis is common in the subclass. Molecular phylogenetic studies support the naturalness of the subclass with the addition of two carnivorous families - the Nepenthaceae and Droseraceae. The Caryophyllidae is either part of or closely related to the new, expanded Rosidae.