The Chenopodiaceae and Amaranthaceae are closely related families consisting of about 174 genera and 2,050 species of world-wide distribution. The Chen-Am alliance is ecologically important and also contains a number of economically important crop and weedy species. The alliance is further noted for C4 photosynthesis as well as for adaptations for xeric and saline environments. Despite their importance, the Chen-Ams have not been well investigated morphologically and the significance of several characters has been debated (i.e. ovule number and embryo type). As part of our ongoing phylogenetic research of the Chen-Am alliance we characterized and optimized several morphological characters including vegetative, floral, stamen, ovule, fruit, and inflorescence characters onto an independently derived ndhF based phylogeny. Several characters reveal phylogenetically informative patterns that will be incorporated into future revisions of the alliance.

Key words: Amarathaceae, Chenopodiaceae