Heracleum mantegazzianum

Imported as an ornamental, but causes serious dermatitis. Cow parsnip, a native, can be mistaken for giant hogweed. Grows up to 10 feet in breadth, and 15-20 tall.  Stems are hollow, 2 - 4 inches in diameter and blotched with purple. Flowers from June - July with many large, white flowers in an umbel shaped arrangement. Sap will cause skin to be sensitive to ultravoilet light causing blisters, severe burns and permanent blindness, if it gets into eyes.