Identification
 Leaves Ottawa National Forest |
 Rosettes Ottawa National Forest |
 Stem Connecticut Invasive Plant Working Group |
 Compound umbel Ottawa National Forest |
 Main and satellite umbels T. English - CIPWG |
 Ripe seeds USDA-APHIS |
 Plant in full bloom Donna R. Ellis, U of CT |
 Dead stalks Randy Westbrooks, USGS |
Habitat & Invaded Sites
 Backyard patch Ottawa National Forest |
 Residential patch Ottawa National Forest |
 Woodland patch Leslie Mehrhoff, U of CT |
 Giant hogweed survey, UK Photographer unknown |
Look-Alikes (Native)
Cow parsnip, Heracleum lanatum
 Cow parsnip patch in bloom S. Garske - GLIFWC |
 Cow parsnip S. Garske - GLIFWC |
 Cow parsnip leaf S. Garske - GLIFWC |
 Cow parsnip inflorescence S. Garske - GLIFWC |
Purplestem angelica, Angelica atropurpurea
 Stalk of bolting plant S. Garske - GLIFWC |
 Compound leaf S. Garske - GLIFWC |
 Angelica in bloom S. Garske - GLIFWC |
 Side umbel of angelica S. Garske - GLIFWC |
Water hemlock, Cicuta maculata (poisonous!)
 Water hemlock leaf and stem (poisonous!) S. Garske - GLIFWC |
 Water hemlock in bloom (poisonous!) S. Garske - GLIFWC |
 Flowers in umbels (poisonous!) S. Garske - GLIFWC |
 Flowerheads or umbels (poisonous!) S. Garske - GLIFWC |