Bendy-eye, Common Caltrop, Common Puncture Vine, Double Gee, Malta Cross, Bullhead, Goat-head.
Flowers: Small, yellow blooms that open exclusively in the mornings. Flowers have 5 petals and are 7 – 15 mm across.
Stem: Combined with the leaves, this plant forms an eye-catching pattern of vegetation. Stems are reddish-brown, covered in small, white hairs, and branch off from their central axis, up to 2 m long. White Puncture Vine normally grows in dense mats, it may take a more upright form if it is competing for light.
Leaves: This plant produces opposite, oblong leaflets all along its vines, with the upper half boasting a deep green, compared to its lighter underside. Each leaf is composed of 3 – 8 pairs of opposite leaflets, each leaflet being 5 – 15 mm long and 3 – 5 mm wide.
Seeds: Are sharp-pointed and 2 – 6 mm long. Each seedpod consists of 5 sections that, at maturity, break into tack-like structures (burs) with sharp spines. Two to four seeds are found within each bur.
Roots: Puncture Vine manages nutrients through its shallow taproot system.
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.
Habitat and Origin
Puncture Vine originates from the Mediterranean region. It was probably transported to North America in sheep’s wool. In North America, it was first recorded in California in 1903. The first Canadian record of Puncture Vine dates back to the early 1970’s.
This resilient plant thrives under a wide range of conditions, growing among dry, disturbed sites as well as compact, fertile areas. Its favourite conditions, however, include sandy, dry, loose soils and full sun. Typical regions of infestation include croplands, orchards, roadsides, railways and dune ecosystems.
Propagation & Vectors of Spread
Puncture Vine reproduces solely by seed. Without competition, a single plant may produce up to 1 million seeds in a season.
“Hitchhiking” is the primary mechanism of dispersal for Puncture Vine, as the fruits easily become attached 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.
Ecological, Economic, & Health Impacts
- Out-competes native flora
- Forms dense, impenetrable layers of vegetation
- Thorny burs puncture farming equipment, tires and can damage the hides of livestock
- Causes injury to humans, wildlife, and livestock through contact with its spikey burs.
- If ingested, Puncture Vine leaves contain a compound known as saponin, which can be toxic to livestock (especially sheep).
What Can I Do?
Puncture Vine is NOT currently found throughout the Sea to Sky Corridor, so the best approach to controlling its spread is by PREVENTION.
Learn to identify Puncture Vine: use the images presented in 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 clicking here.
- 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 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.
- Young weeds are the most responsive to hand-pulling, though it’s only effective if pulled annually, before seed set.
- After years of consistent removal, the plant’s seed bank will be depleted.
- If Puncture Vine infestations have already produced seedpods, and been pulled, they must be burned for proper disposal.
Herbicides Glyphosate, 2,4-D, or dicamba can be used on Puncture Vine, though are best suited for medium-large infestations.
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.
Two species of weevils have been considered for release in the United States, one of which is active in B.C. The larvae of the Microlarinus lareynii, which was released in Osoyoos in 1986, feed on Puncture Vine’s seeds, while the adults consume its foliage. However, this agent has yet to successfully establish in the Okanagan.
M. lypriformis has been released in Washington, Idaho, and Oregon, and produces larvae that attack the plant’s stems. As current reports state, only Oregon has proved the species to be a successful biocontrol option.
There are therefore no biocontrol agents for Puncture Vine in BC at this time.
- Canadian Food Inspection Agency, Tribulus terrestris, https://www.inspection.gc.ca/plant-health/seeds/seed-testing-and-grading/seeds-identification/tribulus-terrestris/eng/1475881856080/1475881856436
- E-Flora BC, Tribulus terrestris, https://linnet.geog.ubc.ca/Atlas/Atlas.aspx?sciname=Tribulus%20terrestris
- Invasive Species Compendium, Tribulus terrestris, https://www.cabi.org/isc/datasheet/54447#todescription
- Invasive Species Council of BC and Government of BC, Field Guide of Noxious Weeds and Invasive Plants in BC (pg. 64), https://bcinvasives.ca/documents/Field_Guide_to_Noxious_Weeds_Final_WEB_09-25-2014.pdf
- Lady Bird Johnson Wildflower Center, Argentina anserina, https://www.wildflower.org/plants/result.php?id_plant=ARAN7
- University of California Agriculture & Natural Resources, Puncturevine, http://ipm.ucanr.edu/PMG/WEEDS/puncturevine.html