Cocklebur is a summer annual weed in the daisy family that is native to Europe and has naturalized elsewhere. They grow 2-4 feet tall and prefer moist to wet sandy loam or loams in full sun to partial shade. It cannot grow in full shade. They have minimal branching, except for short side stems that develop from the leaf axils. The central stem ends in a spike-like raceme similar to the racemes of the leaf axils. Cocklebur is monoecious, that is having both male and female reproductive organs on a plant. Each raceme produces several male compound flowers along the upper half and several female compound flowers along the lower half. Pollination occurs by wind, reproduction by self-seeding. This often leads to colonies being formed. Insects, Diseases, and Other Plant Problems: Their aggressive growth can be a problem for pastures, fields, roadsides, along stream banks, dunes or poorly drained areas. The burs attach to clothing and animal fur for dispersal by short hooked prickles. Young Cocklebur seedlings exude toxic chemicals that can affect germination of surrounding plants, or kill seedlings.
Curated pairwise relationships between this plant and others in the library — who feeds
whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.
No curated interactions recorded for this species yet.
Also noted by NC State
Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell
apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.
Full sun (6 or more hours of direct sunlight a day) | Partial Shade (Direct sunlight only part of the day, 2-6 hours)
Soil texture
Clay; Loam (Silt); Sand
Soil pH
Acid (<6.0); Alkaline (>8.0); Neutral (6.0-8.0)
Soil drainage
Good Drainage | Moist | Occasional Flooding | Occasionally Wet
NC region
Coastal; Mountains; Piedmont
Mature size
Height: 2 ft. 0 in. - 4 ft. 0 in. | Width: 1 ft. 0 in. - 0 ft. 4 in.
Growth rate
Rapid
Maintenance
High
Canopy layer
4 - Herbaceous (3-15 ft)
Form & Appearance
Habit / form
Erect
Texture
Coarse
Foliage
Deciduous
Leaf color
Green
Leaf type
Simple
Leaf arrangement
Alternate
Leaf shape
Cordate; Deltoid; Lanceolate; Linear; Ovate
Leaf margin
Lobed; Serrate
Leaf feel
Rough
Leaf size
> 6 inches long, 3-6 inches wide
Hairs present
Yes
Leaf detail
Up to 8" inch long ovate to triangular leaves with stiff hairs and irregularly lobed margins. The upper leaf surface has a sandpaper texture. The underside is a light green then the upper.
Flower color
Green; Purple/Lavender
Flower form
Head; Insignificant; Raceme; Spike
Flower shape
Tubular
Flower size
< 1 inch
Flower detail
Greenish flowers in the axil of leaves. Monoecious heads of either pistillate or staminate florets. Pistilate heads develop into hard, pricky bur
Bloom time
Fall; Summer
Fruit color
Black
Fruit type
Achene
Fruit size
< 1 inch long
Fruit detail
1/2 to 1.5-inch 2-chambered, ovoid shaped bur covered in hooked prickles.
Stem color
Green; Red/Burgundy
Stem detail
Stems have short white hairs and dark red or black streaks. They can be round or slightly ribbed.
Wildlife & Ecology
Native status
Non-native
Origin
Europe
Distribution
Throughout the country. Naturalized or invasive in most of the world.
Wildlife value
Xanthium strumarium is not a significant food source for pollinators or wildlife. However, many insects do feed on this plant.
Play value
Wildlife Larval Host
Food & Medicine
Harvest time
Fall; Summer
Fruit type
Achene
Uses (ethnobotany)
Inspired the invention of velcro. Fruits were used as a yellow dye. The fruit, a prickly bur, hitchhikes on fur, hair and clothing. Native American tribes used the cocklebur medicinally, as a food source (seeds), and in ceremonies. The seed pods may have been used to make a yellow dye.