Puncturevine (Tribulus terrestris)
Caltrop Family (Zygophyllaceae)
Description: Annual with prostrate or somewhat ascending, mat forming, trailing stems, each about 1/2 to 5 feet long. Leaves opposite, hairy, and divided into 4 to 8 pair of leaflets. Flowers yellow, with 5 petals. Fruit hard, about 1/2 inch across, separating into five parts when mature, each with 2 to 4 sharp, hard spines, resembling a goat's head.
Habitat: Native to Mediterranean. Grows in pastures, cultivated fields, waste areas and disturbed sites such as roadways. Toxic to livestock in vegetative condition. It particularly thrives in sandy and sandy loam soils. The hard spiny burs damage wool, and may be injurious to livestock as well as humans' bare feet, dogs' pads, and bike tires. Other common names include goathead, caltrop, and Mexican or Texas sandbur.
Distribution: Puncturevine is widespread throughout northeastern California and northwestern Nevada with scattered occurrence.
Flowering Period: April to October.
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