Key identifying traits
- Flowers are small,
inconspicuous, and creamy green
- Plants grow up to 3’
tall
- 1” spines are found in
leaf axils & at stem nodes
- Leaves are bright to
dark green & hairy on the upper surface; mostly three-lobed with
the center lobe much longer than the other two; up to 3” long
with a prominent white mid-vain
- Fruits are oval burs up
to 1/2” long with hooked spines & contain 2 seeds per bur
Biology and ecology
- An annual reproducing by
seed
- It is native to Chile
but now widespread in Europe, Asia, North and South Africa,
North and South America, and Australia
- The hooked spines of the
fruit enable it to adhere to animals and be transported long
distances
- The seeds and
young cotyledon plants are toxic to livestock
- It grows in a wide
variety of soil types and most frequently found in disturbed
areas and barnyards but has also invaded pastures & fields
Control
Prevention –
Learn to identify plants; start monitoring early in the season; do
not allow plants to produce seed
Biological –
There have been biological agents found in California, Texas and
Kansas
Cultural –
Plant competitive grass or other cover crop
Mechanical –
Cultivation is effective on seedlings; mowing can also help if done
before burs develop
Chemical – Herbicides with
dicamba, mecoprop, plus
2,4-D are said to control spiny cocklebur; the
PNW Weed Management handbook does not have specific control
recommendations for this plant
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Photo © 2003 Kurt Stueber |
