Tribulus terrestris is an annual plant in the caltrop family (Zygophyllaceae) widely distributed around the world.

An aggressive and hardy invasive species, T. terrestris is widely known as a noxious weed because of its small woody fruit – the bur – having long sharp and strong spines which easily penetrate surfaces, such as bare feet or thin shoes of crop workers and other pedestrians, the rubber of bicycle tires, and the mouths and skin of grazing animals.

[3] Like many weedy species, this plant has numerous common names according to the world region,[3] including goathead, bull's head, gopher-head, caltrop, cat-head, devil's eyelashes, devil's-thorn, devil's-weed, puncturevine, and tackweed.

[2][3][4] Tribulus terrestris is a taprooted herbaceous plant that grows as a summer annual in temperate climates.

[3] In Southern California, it blooms from April through October, where it is highly invasive in waste places and disturbed sites.

[3] The bur spines point upward, where they stick into feet and fur of animals, serving the purpose of seed dispersal.

[12] Although its extract has been used as a dietary supplement since the 1980s in belief that it increases testosterone levels to aid body building or sexual enhancement in men, T. terrestris did not consistently affect testosterone levels in controlled studies, has not been proven to be safe, and may adversely interact with prescription drugs.

[12][13] High-quality research on T. terrestris extract has not been conducted, and no reviews indicate that it has strength-enhancing properties, or anabolic steroid effects for use as a bodybuilding supplement or sexual enhancement.

However, T. terrestris is considered a hardy plant, and its seeds remain viable for up to three years, making complete eradication difficult.

Where ground-cover is newly planted, diligently monitor to ensure no T. terrestris seeds have sprouted in the area.

Removing the plant should be done before or during flowering to prevent seed formation (late spring and early summer in many areas).

Partial removal will allow regrowth, but may be the only option in compacted soil; in this case, repeated cutting will exhaust the plant's energy storage.

In June 2014, the town of Irrigon, Oregon, announced it would pay a bounty of one dollar for each large trash bag of puncturevine.

Pre-emergent chemicals can be most effective in combination with manual control; it prevents the annual seeds of T. terrestris from sprouting to make new plants.

Two weevils, Microlarinus lareynii and M. lypriformis, native to India, France, and Italy, were introduced into the United States as biocontrol agents in 1961.

Microlarinus lareynii is a seed weevil that deposits its eggs in the young burr or flower bud.

[citation needed] When ingested, phylloerythrin accumulates in the blood as a byproduct of chlorophyll degradation; however, adverse reactions have not been confirmed in humans.