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Common cocklebur infestation. Photo Credit: Jan Samanek, Phytosanitary Administration, Bugwood.org -
Common cocklebur leaves. Photo Credit: David J. Moorhead, University of Georgia, Bugwood.org -
Common cocklebur seed pods. Photo Credit: Jan Samanek, Phytosanitary Administration, Bugwood.org -
Common cocklebur seed pods. Photo Credit: Jan Samanek, Phytosanitary Administration, Bugwood.org -
Common cocklebur infestation. Photo Credit: David J. Moorhead, University of Georgia, Bugwood.org
Note: Common cocklebur is a native plant to Oregon. Its toxicity to livestock and ability to outcompete crops make it a nuisance in certain settings.
Also known as: rough cocklebur, clotbur, cocklebur, ditchbur.
Common cocklebur is a summer annual that has big, broad leaves. It can outcompete row crops and is toxic to livestock if consumed.
Description:
| Life Cycle: | Annual (life cycle lasts one year) |
| Early Detection and Rapid Response species: | No |
| Height: | Grows up to 4 feet (1.2 meters) tall |
| Leaf Description: | It grows many stems. Stems are hairy and have purple spots. Board leaves are dull green on top and pale green on the underside. Each leaf has three lobes with toothed edges. They grow alternately along the stem. |
| Fruit & Flower Description: | Common cocklebur grows male and female flowers on the same plant. Female flowerheads are yellow-green and oblong. Male flowers are smaller and rounder. Female flowerheads mature into a stiff, brown seed capsule which persists through winter. The seed capsules have stiff burs that can catch fur or clothing. |
| Bloom Time: | July to October |
Habitat:
- Common cocklebur tolerates a wide range of soil and sun conditions.
- It typically grows in cultivated fields, pastures, and along field edges and roads.
Impact:
- It can rapidly form large stands, displacing other plants. It can particularly be problematic in row crops.
- It is toxic to livestock when left to grow in pastures and can lead to death if eaten.
What you can do about it:
- It can cause skin irritation. Protect yourself by wearing gloves, long sleeves, and long pants whenever handling this plant.
- Small patches can be controlled with hand pulling. Manual removal is most effective before July when burrs have not developed.
- Mowing large populations before or during the flowering stage can be effective. A second treatment may be required to control the infestation.
Look-alikes:
Common burdock (Arctium minus) is a weed in Oregon that can be confused with common cocklebur. Common burdock has smooth leaf edges while common cocklebur leaf edges are toothed.
Noxious Weed Listing:
| State of Oregon: | Not listed |
| State of Washington: | Not listed |
More Resources:
Download the Common Cocklebur Best Management Practices factsheet
- Pacific Northwest Weed Management Handbook: Common cocklebur
- University of California, Weed Research & Information Center: Rough cocklebur