Puncturevine Tribulus terrestris L.
Zygophyllaceae (Caltrop family)
Prostrate, mat-forming summer annual.
Opposite, even pinnately compound, with many small, oblong leaflets.
Prostrate, covered with stiff hairs and branching in all directions, forming circular mats.
Flowers and fruit
Flowers are small with five yellow petals. Podlike fruit are woody with five triangular burs and sharp spines. Spines are stout enough to puncture tires.