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   Yellow Toadflax Linaria vulgaris   Rosette Leaves are two and one-half inches in length, narrow, and pointed. Adult This perennial weed grows to two feet tall. Flower Flowers are about one inch long, yellow with an orange throat, and have long tails. They look similar to snap dragon flowers. Bloom is in late spring into summer. Yellow toadflax came from Eurasia. It is an aggressive invader of rangeland, roadsides, field edges, and waste areas. An extensive root system makes this weed difficult to control. It reproduces by seeds and roots. 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