Plants on graded deep sands on backside of barrier dunes fronting ocean side shoreline with Ipomoea pes-caprae, Canavalia rosea, Vigna luteola, Chamaecrista fasciculata,
hillside slope with calcareous gravels on over white blocky limestone outcrops. An exceptionally rich and diverse flora site less than 100 yards east of Coahuila state line.