puncturevine, bullhead, caltrop, goathead, Mexican sandbur, puncture vine, Texas sandbur
- Tribulus terrestris is an annual, low-spreading forb native to the Mediterranean.
- Leaves are opposite, hairy, 1-3 in. (2.5-7.6 cm) long, and divided into 8-18 oblong leaflets.
- Flowering occurs from midsummer to frost, when 5-petaled, yellow, 0.5 in. (1.27 cm) wide flowers develop singly in the axils of the leaves.
- Fruit are circular, spiny burs that split into 5 sections. Burs can cause injury to bicycle tires, bare feet, and even small truck tires.
- Ecological Threat
- Plants invade roadsides, pastures, fields and other disturbed areas. Plants are toxic to sheep and other grazers.
- Oregon Department of Agriculture Plant Programs, Noxious Weed Control
- University of California, Jepson Flora Project
- Flora of China, www.eFloras.org
- USDA NRCS PLANTS
- USDA ARS GRIN
Images from Bugwood.org