Notobubon galbanum

Notobubon galbanum, re-classified from Peucedanum galbanum in 2008, commonly called the blister bush or hog's fennel, is a South African plant that is best known for its ability to cause painful blistering after contact. In Afrikaans this plant species is known as bergseldery (i.e., "mountain celery"). The plant is in the family Apiaceae, subfamily Apioideae. Although it is in the same family as edible plants such as the carrot and herbs such as fennel and dill, it is not edible and touching it can cause severe blistering particularly if the irritant chemicals are exposed to sunlight (phytophotodermatitis)....read more on Wikipedia.