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   Blue Lettuce Lactuca pulchella   Adult Blue lettuce is native to the United States. It reproduces by seed and lateral roots. It has a wide habitat preference, doing extremely well on heavier soils. It is typically found in rangeland, pastures, cultivated fields, marshes, along waterways, and roadsides. Flower This perennial plant grows up to four feet tall. Roots are vertical and lateral. The stems ooze milky fluid when damaged. Leaves are two to six inches long and blue-green in color with a light midvein. Lower leaves often are toothed, whereas upper leaves have smooth margins. Flowers are about one inch in diameter and are blue to purple. 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