This volume and its companion, Monocots, Comparative Biology and Evolution, excluding Poales 2006, contain papers presented at the Third International Conference on the Comparative Biology of the Monocotyledons, Monocots III, and the Fourth International Symposium on Grass Systematics and Evolution, Grasses IV, hosted by Rancho Santa Ana Botanic Garden, Claremont, California, in 2003.

This work contains 42 original scientific papers from the conferences whose goals were, in part, to offer a strong core program in systematics while incorprating newer, relevant fields such as developmental biology and genomics,and to address the timely and challenging issue of data integration.