Tribulus

Tribulus is a genus of plants found in many warm regions. The best-known member is T. terrestris (puncture vine), a widespread weed and also the source of a dietary supplement. T. terrestris has been said to raise natural testosterone levels if taken as a supplement. There have been no studies that show a direct correlation between the use of tribulus and an increase in natural testosterone.

Tribulus species are perennial, but some grow as annuals in colder climates. The leaves are opposite and compound. The flowers are perfect (hermaphroditic) and insect-pollinated, with fivefold symmetry. The ovary is divided into locules that are in turn divided by "false septa" (the latter distinguish Tribulus from other members of its family).

Some species are cultivated as ornamental plants in warm regions. Some, notably T. cistoides, T. longipetalus, T. terrestris, and T. zeyheri, are considered weeds. Tribulus omanense is the national flower of Dubai. Thirteen species of Tribulus are accepted by The Plant List, but there are many names still unresolved and needing further study.