The coastal prairies and marshes of the Texas Gulf Coast are among the richest grazing lands in the state. Traditionally they have been the site of some of the largest ranches in Texas; today the ranches are primarily cow-calf operations that use forage grasses as well as “tame” grasses such as Bermuda and some bluestems. This region is also an excellent natural habitat for upland game and waterfowl and is an important recreational hunting and fishing area. Urban and industrial development has increased in the region as well; since World War II the prairies and marshes have seen the greatest industrial development of any part of the state, and the effects of that development on the environment are of great concern. Grasses of the Texas Gulf Prairies and Marshes serves as a useful manual for the identification and study of grasses of the prairies and marshes adjacent to the Gulf of Mexico from northern Mexico to western Louisiana. This field guide is a systematic and descriptive treatment of the grasses found on that coastal zone and includes keys to the 98 genera and 303 species. For convenience in locating specific taxa, the grasses are listed alphabetically by genus and then by species within genus; common names are provided when they are known. Species descriptions include information on longevity, dimensions of the entire plant and of the spikelets, and descriptions of the grass’s habitat and distribution and rating of its value for stock or wildlife. The notes on abundance, habitat, and distribution provide information on the ecological niche of each species. Where known, the requirements of the species, such as moisture, soil, and other environmental conditions are given. Heavily illustrated with line drawings of grass plants and plan parts, this field guide will be useful for stock raisers, wildlife managers, and environmentalists as well as grass taxonomists and range scientists.