The floristic characteristics that define the northern Chihuahuan Desert are explored using indirect and direct ordinations. The floristic, geographical and environmental data from a large releve dataset are used to evaluate species distributions within the Chihuahuan Desert and across to the adjacent Short Grass Steppe and Colorado Plateau ecoregions. The focus is on delineating more precisely the floristic boundaries between these provinces and extracting pertinent ecological and geographical information about key indicator species.

Key words: Bouteloua eriopoda, Bouteloua gracilis, Chihuanhuan Desert, indicator species, Larrea tridentata, ordination