Poison ivy: Toxicodendron radicans

Poison ivy is found east of the Rocky Mountains from Canada down to Florida. It is an adaptable, woody perennial weed. All types of poison ivy have three leaves, two leaflets grow on opposing sides and the third stands by itself at the end of the stalk.

Poison ivy (Toxicodendron radicans)

Poison Ivy can grow as a shrub or form a vine. It may carpet the ground while other poison ivy climb tree trunks, stone walls, and fences.

The plant is well known for causing an itching, irritating, and sometimes painful rash in most people who touch it.  The rash is caused by urushiol, a clear liquid compound in the sap of the plant.

Four characteristics  to identify poison ivy:
  • clusters of three leaflets
  • alternate leaf arrangement
  • lack of thorns
  • each group of three leaflets grows on its own stem (which connects to the main vine)
Rhymes warning about poison ivy:
  • “Leaflets three; let it be”
  • “Hairy vine, no friend of mine.”
  • “Berries white, run in fright”
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