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Xanthium strumarium is often confused with:
Senecio vulgaris Senecio vulgaris L.
Plants that fill a similar niche:
Chenopodium album Chenopodium album
Ambrosia artemisiifolia Form
Euphorbia hirta leaf arrangement
Xanthium strumarium has some common insect problems:
Aphids Found on Flowers and Foliage
Beetles Found on Flowers and Foliage

Woolgarie Bur Xanthium strumarium

Previously known as:

  • Xanthium americanum
  • Xanthium chinense
  • Xanthium speciosum
Phonetic Spelling
ZAN-thee-um stroo-MAR-ee-um
This plant has high severity poison characteristics.
See below
Description

Cocklebur is a summer annual weed in the daisy family that is native to North America and has naturalized elsewhere. It is found in all areas of NC. 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.

The seeds were a food source for the now extinct Carolina Parakeet, which was the only parrot native to eastern North America.

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.  

 

See this plant in the following landscape:
Cultivars / Varieties:
Tags:
#poisonous#summer annual#weed#weedy#summer annual weed#high maintenance#fast growing#aggressive#wind dispersed seeds#wind pollinated#allelopathic#warm season weed
 
Cultivars / Varieties:
Tags:
#poisonous#summer annual#weed#weedy#summer annual weed#high maintenance#fast growing#aggressive#wind dispersed seeds#wind pollinated#allelopathic#warm season weed
  • Attributes:
    Genus:
    Xanthium
    Species:
    strumarium
    Family:
    Asteraceae
    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.
    Life Cycle:
    Annual
    Recommended Propagation Strategy:
    Seed
    Country Or Region Of Origin:
    North and South America
    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
    Dimensions:
    Height: 2 ft. 0 in. - 4 ft. 0 in.
    Width: 1 ft. 0 in. - 0 ft. 4 in.
  • Whole Plant Traits:
    Plant Type:
    Annual
    Ground Cover
    Herb
    Native Plant
    Poisonous
    Weed
    Woody Plant Leaf Characteristics:
    Deciduous
    Habit/Form:
    Erect
    Growth Rate:
    Rapid
    Maintenance:
    High
    Texture:
    Coarse
    Appendage:
    Prickles
  • Cultural Conditions:
    Light:
    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
  • Fruit:
    Fruit Color:
    Black
    Display/Harvest Time:
    Fall
    Summer
    Fruit Type:
    Achene
    Fruit Length:
    < 1 inch
    Fruit Description:
    1/2 to 1.5-inch 2-chambered, ovoid shaped bur covered in hooked prickles.
  • Flowers:
    Flower Color:
    Green
    Purple/Lavender
    Flower Inflorescence:
    Head
    Insignificant
    Raceme
    Spike
    Flower Bloom Time:
    Fall
    Summer
    Flower Shape:
    Tubular
    Flower Petals:
    Bracts
    Flower Size:
    < 1 inch
    Flower Description:
    Greenish flowers in the axil of leaves. Monoecious heads of either pistillate or staminate florets. Pistilate heads develop into hard, pricky bur
  • Leaves:
    Woody Plant Leaf Characteristics:
    Deciduous
    Leaf Color:
    Green
    Leaf Feel:
    Rough
    Leaf Type:
    Simple
    Leaf Arrangement:
    Alternate
    Leaf Shape:
    Cordate
    Deltoid
    Lanceolate
    Linear
    Ovate
    Leaf Margin:
    Lobed
    Serrate
    Hairs Present:
    Yes
    Leaf Length:
    > 6 inches
    Leaf Width:
    3-6 inches
    Leaf Description:
    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.
  • Stem:
    Stem Color:
    Green
    Red/Burgundy
    Stem Is Aromatic:
    No
    Stem Buds:
    Hairy
    Stem Cross Section:
    Round
    Stem Form:
    Straight
    Stem Surface:
    Hairy (pubescent)
    Stem Description:
    Stems have short white hairs and dark red or black streaks. They can be round or slightly ribbed.
  • Landscape:
    Landscape Location:
    Naturalized Area
    Woodland
    Problems:
    Allelopathic
    Poisonous to Humans
    Problem for Horses
    Weedy
  • Poisonous to Humans:
    Poison Severity:
    High
    Poison Symptoms:
    Poisoning leads to vomiting, weakness, muscular spasms and sometimes coma and death of the animal.
    Poison Toxic Principle:
    The glycocide carboxyatractyloside is present in the cotyledon stage. It causes hypoglycemia in animals that ingest the seedling
    Causes Contact Dermatitis:
    No
    Poison Part:
    Leaves
    Seeds