(Tribulus terrestris L.)
Caltrop family - Zygophyllaceae
Photo from Weeds of the West, revised ed.
Growth Habit: Annual, mat forming, trailing stems to 5 feet long.
Leaves: Opposite, hairy, divided into 4-8 pairs of leaflets. Oval leaflets 1/4 to 1/2 inch long.
Stem: Prostrate, trailing, hairy, many branched from root crown.
Flower: 5 petals, yellow, in leaf axils, to 1/2 inch wide.
Seeds: Fruit break into 5 sections with 2-4 seeds per capsule. Capsules tack like structures with 2 sharp spined, resembling the head of a goat.
Habitat: Croplands, pastures, along transportation rights-of-way and in urban areas.
Biological Controls: Puncturevine seed weevil (Microlarinus lareynii), Puncturevine stem weevil (Microlarinus lypriformis).
Herbicides: Roundup Ultramax, Plateau, Telar XP, E2, Oust XP and Method
Produced by Wyoming Weed & Pest Council in cooperation with Sandoz Crop Protection Corp.