Sunday, April 6, 2008
The classification of poison ivy, a member of the cashew family, Anacardiaceae, is confused because of the plant's highly variable growth forms. Some authorities recognize at least two species of poison ivy, Rhus racicans and R. toxicodendron, whereas others consider these a single species. (The confusion is added to by referring to the shrubby form of these plants as Poison Oak). Poison ivy is a trailing or climbing woody vine or a shrub like plant containing a poisonous, oily substance called urushiol or toxicodendrol. The leaf consists of three leaflets, which are commonly dark glossy green above and slightly hairy below. Small, yellowish of greenish flowers are followed by berrylike drupes. Poison ivy is native to eastern North America but is now found from Southern Canada to
Guatemala and in Bermuda, the Bahamas, and parts of Asia. Contamination can occur through direct or indirect with the plants or by exposure to smoke from burning plant parts. The resulting dermatitis, which may spread from the site of contact can range from itching and inflammation to severe swelling with oozing blisters. Treatment with cortisone creams and ointments helps.