Rosa multiflora (multiflora rose), introduced to America from Japan for ornamental pur­poses 200 years ago, was promoted in Iowa during the mid-1930s as a "living fence" that would help to conserve soil and provide cover for wildlife. Multiflora rose has since natural­ized, and today some two million acres of Iowa land are infested with this pest, which renders pastures unusable (dense stands exist in coun­ ties south of a line from West Pottawattamie through Winneshiek, affecting the southeast­ern two-thirds of the state). Cattle avoid the prickly stems, and grass dies beneath its thick growth. Although tillage can control the weed, land in permanent pasture or under the Conser­vation Reserve Program is at risk for the spread of multiflora rose.