Chilopsis D.Don

Chilopsis is a monospecific genus whose only species Chilopsis linearis (Cav.) Sweet, grows in the desert washes and dry streambeds of southwestern United States and Mexico, its penetrating roots enabling it to access groundwater. It is closely related to Catalpa, with which it has been crossed to produce the hybrid genus ×Chitalpa. With a range that extends to the edges of the Great Plains, Chilopsis is hardier than sometimes assumed, though it will not tolerate heavy wet soils and needs summer heat to flower well. Cross-breeding with the closely related Catalpa produces the intergeneric hybrid ×Chitalpa, with broader leaves and wider tolerances.