Species Facts:

British Yellow Head (Yellow Starwort or British Elecampane), Inula britannica., is a rhizomatous perennial or biennial in the aster family. It is now widespread in the Old World, occurring from Japan to Spain and north to Scandinavia and Siberia; it occurs primarily in moist habitats including ditches, stream banks, wet woods, and moist meadows. British Yellow Head has become an aggressive weed in field grown Hostas in the Netherlands, and now its recent detection at several Hosta nurseries in Michigan has led to concern over its potential as a weed in the United States. It apparently arrived in contaminated Dutch hosta and daylily liners.
British Yellow Head spreads aggressively, and is difficult to remove from infested nursery crops. Its roots and rhizomes become intertwined with the root systems of field-grown Hosta in the Netherlands, and remain even after the Hosta rootstocks are washed.
British Yellow Head seeds and rhizomes probably move locally on machinery and hand implements, and the seeds may be moved by wind also. Movement as contaminant materials in Hostas grown in infested nurseries in Michigan also is a possibility. Hostas and daylilies are two of the most popular plants for landscaping, so most nurseries and garden centers stock a large supply. Thus, the potential for an infestation is high.

Portions of this article courtesy of: Forestry Images
Image of a British Yellow Head (Photo from: www.bugwood.org Credit to: Robert Richardson)