(Tribulus terrestris)
Puncturevine is a summer annual forb and is native to Europe. The plant is prostrate or ascending, spreading into mat-forming cover. The stems are trailing and can grow to 1 1/2 to 5 feet long. Leaves are formed into leaflets, with each leaflet containing 5 to 8 oval leaves. The leaves are hairy and opposite. The flowers appear from July through October. They have five petals and are yellow in color. Each flower node will produce fruit, at maturity the fruit will break into 5 seed capsules. Each seed capsule will produce 2-4 seeds. Each capsule is hard and contains many spines, almost tack-like. The shape of the seed capsule has been referred to as a “goathead.” The seeds will propagate after the first moisture of the spring and then any wet period following. Seeds can stay viable for 4 to 5 years.