BACKGROUND: Houndstongue is a native of Europe. It thrives in disturbed soils along roadsides, trails, in pastures, and rangelands. Because of the bur-like seed, it spreads widely along travel corridors as a passenger on clothing or animal fur, It is toxic to livestock.
DESCRIPTION: Houndstongue is a 1 to 4 foot tall biennial. Basal leaves are about 3 inches wide with a hairy surface. Upper leaves are narrower, about 1 inch wide and have a curled appearance and partially clasp the stem. Small reddish purple flowers form in the upper portions of the plant along stems borne in leaf axils. Each flower produces four green, bur-like fruits that turn brown as they mature. Bloom is in early summer.
CONTROL: Herbicides can offer good to excellent control when applied between the rosette and bloom stages. Digging before seed development can offer good control.