Eastern Poison Ivy

Toxicodendron radicans


Eastern Poison Ivy is a native vine that grows throughout Monticello Park, and many people have allergic responses to it. It is in the same family as cashew, pistachio, and mango trees, and it is not a true ivy. The compound "urushiol" causes the response, and its purpose is to help the plant to retain water. The rashes and blisters can be relieved by products available at pharmacies, as well as by a mash made from jewelweed, which grows in Monticello Park. You can prevent the lesions if you wash within two to eight hours of exposure, scrubbing with a washcloth, using plain soap, and rinsing three times. The fluid in the blisters does not spread Poison Ivy. You can spread it if the urushiol on your skin or clothing later comes into contact with doorknobs, telephones, furniture, or other items. You also can get it if you touch a pet who has been in contact with it. Dogs and cats are immune, as are all animals, except hamsters and primates. Urushiol can remain active for years, so touching dead Poison Ivy leaves can cause a reaction. A substance similar to urushiol is found in mango skins and the shells of raw cashews.

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Poison Ivy
A Poison Ivy leaf is composed of three leaflets. You can see fresh green berries that follow white flowers. The berries become white in autumn.

Poison Ivy
Newly emerged leaves in spring

Poison Ivy
What appears to be branches on a tree here are actually branches of Poison Ivy from a thick vine climbing a tree. You can see its red autumn leaves and the berries that make it a "desirable" wildlife plant.

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