The development of viable lignocellulosic-biofuel industries in the United States will require dependable delivery of supplies of feedstocks. The selection of feedstocks ultimately will vary with geographical region across the United States. Dedicated bioenergy crops as sources of lignocellulose are likely to be most productive in the southern regions of the United States due to more abundant sunlight and longer growing seasons. Of course, dedicated bioenergy crops in the southwest must tolerate heat and drought, whereas species grown along the Gulf Coast must tolerate heat as well as variable soil moisture and variable soil-oxygen environments associated with different soil types. Dedicated energy crops for the panhandle of Texas and the Midwest will have shorter growing seasons and will need to be more cold tolerant.