Tribulus terrestris

Non-standard names: Goathead, Mexican Sandbur

Background: Puncturevine originates from Europe.  

Identification: Puncturevine is an annual broadleaf weed. Its stems are prostrate, silky, hairy, and a bright green color. The stem can grow somewhat ascending when in competition for a light source. When prostrate, the trailing stems grow from ½ to 5 feet long, branching and radiating from the root. The stems can form dense mats, fairly large in diameter. When growing in open ground, the habit is prostrate, exposing the maximum amount of burs to the feet of passing animals and vehicles passing by. Leaves are opposite, hairy, and divided into 4 to 8 pairs of leaflets. Leaf size is abut ¼ to ½ inch long and oval. Flowers on this plant are bright yellow, 1/3 to ½ inch wide with five petals. The flowers form leaf axils, solitary, and are only open in the mornings. The seedpod of puncturevine is a cluster of 5 flat spiny burs that break apart into tack-like structures when mature. Each flat spiny bur contains 2 to 4 seeds and 2 sharp spines on its back.

Distribution: Puncturevine is widely scattered over a large portion of the United States. It is commonly found in pastures, cultivated fields (especially lawns, citrus orchards, sorghum, alfalfa, cotton, small grain pastures, and gardens), waste areas, and along highways and roads. Hard spiny burs damage wool, are undesirable in hay and injure livestock. The seed can remain dormant in soil from 4-5 years, which can make removal of the weed difficult. Flowering occurs in July to October.

Control: Contact local pest control advisor.

Photographer: Unknown (if you recognize it, let us know!)