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   Poison Hemlock Conium maculatum   Rosette Leaves are finely divided, having a fern-like appearance. Leaf stems clasp the main stem. Adult This biennial has a large taproot. growing six to ten feet tall Flower The tiny flowers are in umbrella-shaped clusters on the ends of individual stalks. Bloom is in late spring into early summer. Weed Infestation Poison hemlock is a European native . It is commonly found along waterways, roadsides, field edges, and tolerates poorly drained soils. It is often mistaken for parsley and wild carrot. All parts of the plant are toxic. Seed Stems The stems have purple spots, especially at the bases. 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