Puncturevine (Tribulus terrestris)
Keys to ID:
- Yellow, 5-petaled flowers
- Spiny, sharp bur
- Prostrate habit
Identification:
- Life Cycle: Annual
- Growth Form: Forb
- Flower: Small, yellow, 5-petaled flowers are produced in the center of the branched leaves, and appear June thru September.
- Seed/Fruit: spiny fruits are made up of five burs with two spines each that break apart at maturity, and each bur contains two to four seeds (Belliston et al. 2004).
- Leaves: Opposite, hairy, and divided into 4 to 8 pairs of leaflets, each about 1/4 to 1/2 inch long and oval.
- Stem: The horizontal branching stems radiate out from the root crown to form a mat. The hairy stems often grow to 6 feet long, and are green to reddish in color.
- Root: Simple taproot branching into a network of fine roots.
- Propagation: Spreads by seed.
Control:
Mech: Hand pulling is very effective; try to weed before flowers and burs appear. Special care should be taken to rake up all remaining burs and bag and dispose of in the garbage. Large groups of volunteers have been systematically removing puncturevine along community bike paths and on the Jordan River Parkway.
Cautions:
Spiny thorns can be painful if you step on them and can attach readily to soft shoe soles. They may also stick into fingers, so wear gloves while weeding. Dog and cat paws are also sensitive to these thorns, and they can pop bike tires. Care should be taken not to drag seeds from one place to another when walking through infestations or driving a car through infested parking lots.