SGC Admin: Check out the following plants that are known to cause negative reactions when folk come into contact with them..

Giant Hogweed: Human reaction to contact: Symptons occur within 48 hours: Painful Blisters that can sometimes leave purplish scars that can last for years. Keep Away from eyes, may cause temporary or permanent blindness

Cow Parsnip: Human reaction to contact: Stem and Leaves contain chemicals that enhance the sun’s rays upon the skin and can cause sunburn. Can cause burn like blisters and dark spots: Wash the juice off the skin right away and were long sleeves for a few days.

Wild Parsnip: Human contact reaction: The same as Cow Parsnip

Queen Anne’s Lace: Human contact reaction: Exposure to sunlight may aggravate a reaction.

Angelica: Human contact reaction, this plant has long been used for medicinal purposes, but may (on some people) cause dermatitis and serious photo sensitivities if used externally.
source: Whitby This Week July 22 Edition:
Their sources:
wwww.nwplants.com/information/whiteflowers/white_comparison.html