The starthistle, Centaurea calcitrapa, a plant with sharp thorns.
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.
The same object represented as a heraldic charge.
Any of a number of flowering plants in the family Zygophyllaceae, including several members of the genus Kallstroemia and the species Tribulus terrestris, native to warm temperate and tropical regions.
Any of various common weeds of the genus Centaurea
especially Centaurea nigra.