tropical annual procumbent poisonous subshrub having fruit that splits into five spiny nutlets; serious pasture weed
a plant of the genus Trapa bearing spiny four-pronged edible nutlike fruits
Mediterranean annual or biennial herb having pinkish to purple flowers surrounded by spine-tipped scales; naturalized in America
A small, metal object with spikes arranged so that, when thrown onto the ground, one always faces up as a threat to pedestrians, horses, and vehicles.