Weeds: Puncturevine (Tackweed, Goathead) – Tribulus terrestris

• Family: Zygophyllaceae
• Cycle: Annual
• Plant type: Broadleaf

Biology

Puncturevine is a prostrate plant growing from a taproot. Above ground, the branching, trailing stems grow one to six feet and are green to reddish in color. Leaves are opposite. Each leaf is divided into four to eight (or more) pairs of 1/4- to 1/2-inch oval leaflets. Stems, petioles, and leaf undersides are hairy. The upper surfaces of leaves are slightly hairy to hairless. Small, yellow flowers with five petals are borne in the leaf axils. Seeds are borne in a woody, spiny bur consisting of five spined segments which separate at maturity. Spines are hard enough to stick into skin, leather, and tires, and are arranged so that at least one spine is always pointing upwards. SPECIAL INFORMATION: The sharp spines of puncturevine can injure humans and animals. The plant can be toxic to livestock, especially sheep. Puncturevine is designated as a Class ‘B’ noxious weed in WASHINGTON and OREGON. Management may be required by law in your county. In addition, it is on the Oregon noxious weed quarantine list, which prohibits sale, purchase, and transport of plants, seeds, and plant parts. Consult your local Noxious Weed Control Board for more information.

Habitat

Puncturevine grows along roadsides and railroads, in cultivated areas, and waste places. It can grow in compacted soil, sandy soils, or moist, rich soils. It can be a problem in low maintenance turfgrass in central Washington.

Management Options

Use Integrated Pest Management (IPM) for successful plant problem management.

Non-chemical Management

Select non-chemical management options as your first choice!

• Reduce weed establishment by maintaining a healthy planting or turf area to provide competition.
• Cultivation (rototilling or hoeing) will effectively eliminate plants.
• Reduce weed infestation by handpulling weeds.
• Careful digging is useful to manage weed populations. However, digging can carry undesirable weed seed to the surface and foster further germination.

Chemical Management

IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides.

• Apply according to label directions.
• Preemergence products can help suppress it.
• Glyphosate products should be applied as spot treatments only!
• NOTE: Some ingredients listed here are only available in combination.
• Read the label carefully on combination products to make sure the product is suitable for your specific situation.

Additional Images