Puncture Vine

Puncture Vine (Tribulus terrestris)

Report

Photo credit: Lisa Scott

Management Strategy

Synonyms

Bendy-eye, common caltrop, common puncture vine, double gee, Malta cross, bullhead, goat-head.

ID Characteristics

General: Puncture vine is annual forb that forms dense mats up to 1 m wide.

Flowers: Yellow, 5-petaled flowers (7 – 15 mm across). The flowers only open in the mornings.

Stems: Green to reddish brown stems are covered in fine hairs. Puncture vine stems are branched and radiating from a central axis, up to 2 m long. While Puncture vine typically spreads laterally and grows in dense mats, it may take a more upright form if it is competing for light.

Leaves: Composed of 3 – 8 pairs of opposite, oblong leaflets; each leaflet is 5 – 15 mm long and 3 – 5 mm wide. The upper surface of the leaves is darker than the underside.

Seeds: Each seedpod consists of 5 sections that, at maturity, break into tack-like structures (woody burs) with sharp spines. Each bur contains 2 – 4 seeds.

Roots: Shallow taproot.

Similar Species

Native

Silverweed cinquefoil (Argentina anserina): This native species grows along the Pacific coastline, stretching from Alaska all the way southern California. Its edible roots have a flavour profile similar to starchy root vegetables like parsnip and sweet potatoes! Silverweed cinquefoil boasts the classic, 5-petalled, small, yellow flowers and grows hairless leaves with an uneven edge.

Mary-Ellen-Mel-Harte-Bugwood.org-Silverweed-Cinquefoil-1

Photo courtesy of Mary Ellen (Mel) Harte, Bugwood.org

Habitat and Origin

Puncture vine’s exact native range is unknown, but its possible origins include Africa, Europe, and temperate Asia. It was likely transported to North America in sheep’s wool, and was first recorded in California in 1903. The first Canadian record of puncture vine dates back to the early 1970’s.

Puncture vine can tolerate a wide range of conditions, and generally requires less water than most plants. It thrives in dry, loose, sandy or gravely soils and disturbed areas, but will also grow in heavier soils, especially when these are fertile or moist, as well as in compacted soils.

How it Spreads

This plant reproduces solely by seed. Without competition, a single plant may produce up to 1 million seeds in a season. Additionally, puncture vine seeds can remain dormant for 4-5 years , allowing it to form a robust seed bank.

“Hitchhiking” is the primary mechanism of dispersal for puncture vine, as the fruits easily attach to livestock, people, farm machinery, and tires for dispersal. The spiny fruits are aligned so that at least one spine is pointing upwards when lying on the soil surface. Puncture vine may also be dispersed by water or as a contaminant in hay, straw, manure, sand, gravel, and dried fruit.

Impacts

Ecological:

Causes injuries to the mouths, eyes, digestive tracts and skin of livestock.
If ingested, puncture vine is toxic to livestock.
Outcompetes native species.

Economic:

Spiky fruits (burs) can damage equipment on farms and harm livestock.
The burs can puncture skin and bicycle tires.

Stop the Spread

Puncture vine is not yet found in the Sea to Sky region, but is found in neighbouring areas and may arrive here soon. The goal is to prevent puncture vine’s introduction by focusing on education and awareness. If prevention fails, the goal will become immediate eradication following the proposed SSISC EDRR protocol.

Learn to identify puncture vine: use the images on this profile page to learn how to identify puncture vine.

What to do if you spot it: You can report any puncture vine sighting by visiting our reporting page.

DO:

Maintain healthy vegetative communities, and avoid exposing soils, especially in rangeland, or agricultural contexts.
Reseed disturbed soils with early germination, dense seed mixes like alfalfa, or barley.
Regularly monitor properties for weed infestations.
Check wildflower mixes to ensure that they do not contain Puncture Vine.
Ensure that plants are disposed of in a garbage bag, to prevent seeds from spreading.

DO NOT:

Do not transport gravel, sands, and soils from an infested area.
Do not unload, park or store equipment or vehicles in infested areas; remove plant material from any equipment, vehicles, or clothing used in such areas and wash equipment and vehicles at designated cleaning sites before leaving infested areas.

Do not plant puncture vine in a garden, no matter how well-contained its enclosure may seem.

Control

Mechanical Control:

Young plants and small infestations can be controlled by hoeing or hand-pulling plants, but treatment must take place before the plant flowers and sets seed.

Chemical Control:

Chemical treatment works best when used on young and actively-growing plants. Glyphosate, 2,4- D, or dicamba can be used on puncture vine. We recommend that any herbicide application is carried out by a person holding a valid BC Pesticide Applicator Certificate. Before selecting and applying herbicides, you must review and follow herbicide labels and application rates; municipal, regional, provincial and federal laws and regulations; species-specific treatment recommendations, and site-specific goals and objectives.

Biological Control:

A seed (or fruit) weevil (Microlarinus larenyii) was released in the Okanagan in the 1980s, but this agent has yet to successfully establish.