ABSTRACT
Caryophyllids comprise two sister clades that are designated as the orders Caryophyllales and Polygonales. This chapter describes the etymology, synonyms, distribution, diversity, indicators, habitat, key morphology, life history, imperilment, ecology and economic importance of these orders. The order Caryophyllales includes about 8600 species. In North America the obligate wetland (OBL) aquatic species occur within the following five families: Aizoaceae Martinov, Amaranthaceae Adans, Caryophyllaceae Juss, Molluginaceae Raf, and Montiaceae Raf. The Polygonales contain about 2050 species. In North America, obligate aquatic species occur within the following three families: Droseraceae Salisb, Plumbaginaceae Juss, and Polygonaceae Juss. Those families containing OBL aquatic taxa are distributed in both major subclades of Polygonales. Although a concentration of aquatics appears to occur in families close to Polygonaceae, it is important to note that most Frankeniaceae and Plumbaginaceae, and many Polygonaceae are terrestrial. The entire family Droseraceae consists of species adapted to aquatic habitats.
