The Caryophyllales are one of the few higher taxa of theflowering plants ofwhich the size and delimitation againstother taxa is undisputed. However, their derivation fromother taxa and the evolution of families within this orderin unsettled."Systematics and Evolution of the Caryophyllales" reviewsthe important characters of this taxon emphasizing theircontribution and influence towards a new proposal for boththe putative origin of the order and the classification ofits families. New results in molecular genetics,phytochemistry, ultrastructure, and morphology are providedand discussed in relation to both the classical andmolecular systematics of the order. In addition, characterslike betalains and sieve-element plastids, which have playeda major role in shaping the size of the order, and otherslike DNA-data or flower morphologythat can be useful todiscuss the position of the Caryophyllales within higherplants are critically evaluated.