Puncture vine (Tribulus terrestris) is an annual, drought-tolerant plant in the caltrop family (Zygophyllaceae) which thrives in dry, desert climates with poor soil. It is found worldwide and is considered to be an invasive weed in North America.
Puncture vine has pinnately compound opposite leaves with oblong leaflets, solitary yellow flowers in leaf axils, and small spiny capsules as it's fruit.
All parts of the plant contain steroidal sapogenins which are toxic to horses. It can also cause physical injury and photosensitivity, due to it's sharp burrs and chemical components. It has been known to cause neurological symptoms resulting in incomplete paralysis in livestock.