Giant Hogweed (Heracleum mantegazzianum)

• Massively tall plant (15-20 feet)
• Large umbrella shaped flowers
• Hollow stalks with red-purple blotches that have a single erect hair in the center
• Large (2.5-3 feet wide) deeply incised leaves
• Seeds almost ½ inch
• Look for flowers from May to July
• Likes unmaintained urban areas, vacant lots, roadsides, riparian areas

Photos by Tim Butler, Oregon Department of Agriculture