Bermudagrass Johnsongrass Medusahead Quackgrass Field Bindweed Hoary Cress Diffuse Knapweed Russian Knapweed Spotted Knapweed Squarrose Knapweed Purple Loosestrife Perennial Pepperweed Leafy Spurge Yellow Starthsitle Canada Thistle Musk Thistle Scotch Thistle Dyer's Woad Back to main weeds page   Houndstongue Cynoglossum officinale   Rosette Basal leaves are about three inches wide with a hairy surface. Upper leaves are narrower, about one inch wide and have a curled appearance, and partially clasp the stem. Adult Houndstongue is a one to four foot tall biennial. Flower Small reddish purple flowers form in the upper portions of the plant along stems borne in leaf axils. Bloom is in early summer. Weed Infestation 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. Seed Burs Each flower produces four green bur-like fruits that turn brown as they mature. Back to main weeds page   Buffalobur Common Burdock Camelthorn Goatsrue Jointed Goatgrass Poison Hemlock Black Henbane Houndstongue Blue-Flowering Lettuce Western Whorled Milkweed Silverleaf Nightshade Yellow Nutsedge Puncturevine Russian-Olive Saltcedar St. Johnswort Bull Thistle Dalmatian Toadflax Yellow Toadflax Velvetleaf