Poison Ivy (Rhus radicans)

DESCRIPTION: Shrub to 2' or vine. Flowers greenish-white to 1/4" wide. Leaves compound with three leaflets to 4" long. Leaves often, but not always, shiny. Leaflets variously-shaped and may or may not be toothed. Anacardiaceae (Cashew or Sumac) Family.
NATURAL HISTORY: Poisonous ("Leaflets three, let it be"); may cause itchy rash. Flowers bloom April to September. Here, mostly found in wetter areas in canyons.