Also known as: goat’s head, bullhead, Texas sandbur, calthrop, devil’s thorn, tackweed
Puncturevine is aptly named! This invasive plant has spiny seed heads that can puncture bicycle tires, inflatable rafts, animal paws, and even shoes! Be on the lookout as it is starting to pop up in Washington County.
Description:
| Life Cycle: | Annual (life cycle lasts one year) |
| Early Detection and Rapid Response species: | Yes |
| Height: | Lays flat on the ground up to 6 feet (2 meters) across |
| Leaf Description: | Leaves are opposite, oblong, and have several pairs of hairy compoundA leaf consisting of several distinct leaflets joined to a single stem. leaflets. |
| Fruit & Flower Description: | The small yellow flowers have five petals that open in the morning and close in the afternoon. The fruit, also known as a bur, has sharp, rigid spines, which some say resemble a goat’s head. |
| Bloom Time: | April to October |
Habitat:
- Puncturevine is commonly found in pastures, roadsides, beaches (both ocean and river), and parks.
- It is especially troublesome when growing in yards or sports fields where it goes unnoticed until a bur is stepped on.
- It is drought tolerant and grows in most soil types but prefers dry, sandy soils.
Impact:
- Puncturevine is toxic to livestock, particularly sheep and cattle. When livestock consume it in large amounts, it can cause blindness, paralysis, and even death.
- It spreads by seed with animals, humans, and vehicles unknowingly moving it to new locations.
- Its burs are painful to step on and can easily puncture bicycle tires or footwear.
What you can do about it:
- If you think you’ve found puncturevine in Washington County, please report it to the Oregon Invasive Species Hotline.
- Hand pulling or tilling the soil (1 inch or less) is effective in March before plants have begun to produce seeds. When treating puncturevine, wear gloves to avoid being poked and throw it away in a plastic bag in the trash—not your yard waste bin or home compost.
Noxious Weed Listing:
| State of Oregon: | Class B |
| State of Washington: | Class B |
More Resources:
- Pacific Northwest Weed Management Handbook: Puncturevine
- University of California, Weed Research and Information Center: Puncturevine