Fortunately fairly uncommon in Monterey, this plant has pinnate leaves with 6–12 bright green leaflets. The small, bright yellow, 5-petaled flowers are borne in the leaf axils. The fruits are vicious, comprising 4–5 extremely tough, spiny burs. They can puncture tires and cause real damage to animals. Tribulus is the latin word for the 3-pointed caltrop, an ancient weapon still in use today.