Pink, Rose, Red, or Purple Flowered Forbs

Pink, Rose, Red & Purple Flowered Forbs
Black henbane
Blue Mustard
Bull thistle
Canada thistle
Common burdock
Diffuse knapweed
Iberian knapweed
Meadow knapweed
Musk thistle
Purple loosestrife
Purple starthistle
Red clover
Redstem filaree
Russian knapweed
Scotch thistle
Spiny plumeless thistle
Spotted knapweed
Squarrose knapweed
Tall morning-glory


Common Burdock
Arctium minus Bernh. (Aster family, Asteraceae)


Common burdock is a warm-season stoutly taprooted biennial forb; low growing rosette of basal leaves during the first year, but during the second year it becomes 3 to 6 feet tall; second year plant is little branched below, but produces short, flowering side stems above.

Leaves: Rosette leaves are broadly heart-shaped, 6 to 18 inches long, 4 to 14 inches wide, with hollow petioles and wavy and toothed margins; undersides are loosely hairy and light green; stem leaves are much smaller, alternate, and egg-shaped; upper stems terminate in small clusters of flower heads on short stalks.

Flowers: Flowers July to October; flower heads 3/4 to 1 inch wide with pink, lavender, purple or white disk flowers, flower head bracts with hooked spines curving inward; flowers are enclosed in a prickly bur; flowers dry to a bur, and the hooked bracts are often confused with a thistle.

Fruit: The 3/16- to 1/4-inch long achenes are oblong, broader and more truncate at one end than the other; light brown with dark brown speckles; each achene has a crown of fine bristles at the apex.


Cultivated and disturbed or degraded sites in meadows, grassland, woodland, and riparian communities, and roadsides within elevations that generally range below 7,300 feet.


Insect pollinated; reproduces by seed; one plant can typically produce 15,000 seeds.


Native to northern Europe; common burdock is one of nature’s original “velcros;” burs cling readily to fur and clothing and are difficult to remove. This species generally occurs as a weed in wildland areas of the Southwestern Region rather than as an invasive plant.

Collage of 4 images of Common burdock


Forest Service Shield
Invasive plants and weeds of the national forests and grasslands in the southwestern region
Common burdock flowers and foliage Common burdock plant Common burdock leaf Common burdock flowers and foliage