Field sandbur

Cenchrus spinifex, the field sandbur or coastal sandbur, is an annual or short-lived perennial grass in the family Poaceae, native to the warmer regions of the Americas from the southern United States through Mexico, Central America, and the Caribbean to South America, and widely naturalized elsewhere. Plants form tufted or spreading clumps with stems 20-90 cm long that often branch at the base and may root at the lower nodes. The leaf blades are flat or folded, 5-25 cm long and 2-7 mm wide, with rough margins and a membranous-ciliate ligule. The inflorescence is a terminal spike-like raceme of 6-20 burs; each bur is a globose, sharply spiny involucre 4-7 mm in diameter, formed of fused, flattened, retrorsely barbed spines surrounding one to three spikelets. The notoriously injurious burs readily detach and adhere to clothing, fur, and skin, dispersing the seeds. The plant grows on sandy, disturbed, or overgrazed ground, often becoming a serious weed in pastures, lawns, and roadsides.