• Spiky device thrown in the road to puncture a speeding suspect's tires
• Tropical annual procumbent poisonous subshrub having fruit that splits into five spiny nutlets
• Naturalized in America
• Mediterranean annual or biennial herb having pinkish to purple flowers surrounded by spine-tipped scales
• A plant of the genus Trapa bearing spiny four-pronged edible nutlike fruits
• Serious pasture weed