Boundary Invasive Species Society
Erect biennial to short-lived perennial herb up to 1 meter (3 feet tall). Introduced from North Africa as a garden ornamental.
• Purplish-blue, funnel-shaped flowers.
• Flowers on the upper side of short arching branches.
• Seed stalk resembles a viper’s head.
• Entire plant is bristly/hairy.
Typically not eaten by grazing animals so it increases in grazed areas.
Hand pulling or digging is effective if the entire root is removed. Best done when soil is moist. Wear gloves, avoid skin contact. If any portion of flower is beginning to emerge, or if seed heads are
formed, pick, bag, and remove. Selective herbicides are effective.
Reproduction and Dispersal:
By seeds. Most seeds fall near the parent plant, but seeds also travel though infested gravel, water, animals, heavy machinery and vehicles.
Found in gravely riparian areas, roadsides, pastures, and meadows at low to mid-elevations. Well-adapted to dry, rocky, sandy or shallow soils, especially glacial till.
Numerous bright, purplish-blue (occasionally white or pink), funnel-shaped flowers arranged on the upper side of short arching branches. Five petals. Buds are reddishpurple before opening.
Leaves and Stems:
First year basal rosette radiates from central point. Rosette leaves have entire margins, taper towards stalk, and are rounded at the tips. Flowering stalks grow from the rosette during the second year and each year after. Stem leaves are lance-shaped with
entire margins, and are alternately arranged. Stem hairs are painful to touch.
Fruit is a cluster of four angular, wrinkled seeds that are grayish-brown when mature. Each plant may produce up to 2,800 seeds.
Stout, black taproot with smaller fibrous lateral roots. Reaches 60cm (2 feet) long.
It is an aggressive weed with the potential to cause significant degradation to grassland and open forest areas. It is an unpalatable plant that crowds out beneficial native species reducing forage for wildlife and cattle.