Origin:
Native
Life Cycle:
Annual
General Desc:
Bushy annual with spiny burs that get tangled in fur and fabric. Identification notes: Annual, moderately to much branched; leaf blades triangular or broadly ovate, green beneath; flower heads inconspicuous in sessile axillary clusters; flowers produce brownish or yellowish-brownish ellipsoid burs; found in moist, disturbed areas. Height:
To 5 feet Habitat
Habitat Description: Waste places, disturbed moist areas, fallow fields, sandy flood plains and shorelines, stream and river banks, margins of ponds and lakes; sandy and alkaline soils. Plant Communities:
Riparian, Disturbed Areas Elevation: 1000 - 7000 feet Flower Characteristics
Color:
Greenish
Shape:
Inconspicuous in round clusters
Tubular:
N
Flowering Period:
Jul - Oct Description:
Male flowers are tiny, in clusters at top of stem. Female flower heads are in leaf axils and form spiny, up to 1-1/2 inches long burs.
Leaf and Stem Characteristics
Leaf Color:
Yellowish-green
Leaf Type:
Simple
Leaf Shape:
Triangular
Leaf Margin:
Toothed
Leaf Attachment:
Alternate
Leaves Clasp:
N Hairs:
Leaves and stems
Spines:
N
Leaf Description:
Triangular or broadly egg-shaped to circular or kidney-shaped, 1-1/2 to 7-1/2 inches long, 1 to 6 inches wide; surfaces rough-hairy, palmately veined; margins coarsely-toothed and un-lobed or with 3 or 5 shallow lobes; tip rounded or broadly pointed. Fruit and Seed Characteristics
Fruit Color: Brownish or yellowish-brown Fruit Notes: Fruits are cylindrical to barrel-shaped and hard, spiny burs; green drying to brown; burs can stick to fur and clothing and can be very difficult to extract. Seed Notes: Burs contain 2 seeds each in their own compartment. One of the seeds in each bur may germinate the following year with the other seed taking at least 2 years to germinate.
Arizona Cooperative Extension
Yavapai County
840 Rodeo Dr #C
Prescott, AZ 86305
(928) 445-6590