Origin:
Native to Europe, but now spread widely throughout the Pacific Northwest and in localized areas of the Northeast U. S.
Biology:
A perennial with a deep taproot, reproducing primarily from seeds, but also able to re-grow from fragments of the root or crown if the plant is disturbed. Seeds may remain viable in the soil for years, and can sprout at any time during warm weather. Plants that emerge in the fall may over-winter as a small rosette of leaves. The plants are highly invasive and may be found in moist fields, pastures, meadows, or along stream banks, as well as roadsides and in sunny forest areas.
Identification:
Mature plants are upright with numerous thin stems, growing to 3.5 feet in height. Stems are slightly pubescent. Lower leaves are elongate on long stalks, and with slightly wavy or lobed margins. The leaves on upper areas of the stems are much smaller and without stalks. The flowers are produced singly at the tips of the stems and are rose to purple in color, with a large brown bract beneath the petals.
Characteristicts Important to Control:
Mowing to inhibit seed production will be helpful in reducing the spread of the weed. Physical removal may be difficult due to the long taproot and ability to grow from severed root parts. A systemic herbicide applied prior to seed head production will effectively kill the plants.