Cenchrus tribuloides

Cenchrus tribuloides, the dune sandbur, is a grass common along the east coast of the mainland United States as well as Hawaii. It is also known as the sanddune sandbur, long-spine sandbur or sand-dune sandspur and is common in sandy, marshy, or loosely forested areas. It differs from C. spinifex in its larger spikelets and smaller number of spikelets per fascicle, and from C. longispinus in its densely pubescent fascicles, fewer bristles, and wider inner bristles....read more on Wikipedia.