Tribulus terrestris
Zygophyllaceae
Puncture Vine
Mat prostrate to 6 ft. across. Leaves divided, leaflets oval, opposite, 6–12. Flowers small, yellow. Fruit splits into 5 nutlets, each nutlet with 2–4 hard sharp spines. Grows in dry disturbed soils. Mediterranean. This pernicious weed causes flat tires and injured feet, and is named caltrop after a 4-spiked weapon used on the ground to obstruct moving armies.
- Rarity: Common
- Flowering Time: Early Summer, Mid Summer, Late Summer
- Flower Form: 9-6 petals terminal head
- Life Cycle: Annual
- Height: mat
- Habitat: Disturbed, Shrub-Steppe
- Native: No
- Also Known As: Caltrop
