Cakile geniculata

Cakile geniculata, or Gulf searocket, is a fleshy succulent that grows in large patches on the back beach and low dunes. Some leaves are rounded while others have blunt, sawtooth edges. Its small white to lavender flowers, with four petals, appear in clusters throughout the spring, summer and early fall.

References
Duncan, W. H., & Duncan, M. B. (1987). The Smithsonian guide to seaside plants of the Gulf and Atlantic coasts from Louisiana to Massachusetts, exclusive of lower peninsular Florida. Washington, D.C: Smithsonian Institution Press.

Richardson, A. (2013). Wildflowers and other plants of Texas beaches and islands. Austin, TX: University of Texas Press.