Named after Hercules, Heracleum mantegazzianum captures attention with
its impressive foliage: huge, sharply lobed leaves; hollow, hairy,
purple-splotched stems, four inches in diameter; and towering umbrella-shaped
white flowers that bloom in late spring.
Brushing up against this relative of carrots and parsnips
can trigger the release of its toxic sap, which causes the skin to become
hypersensitive to the sun's ultraviolet rays. If not quickly washed with soap
and water and shielded from the sun, affected skin can develop phytophotodermatitis,
an itchy, burning inflammation with blisters, scarring and discoloration, which
might take months to heal. Skin can remain sensitive to sun exposure for years.