Toxicodendron diversilobum (T. & G.) Greene, Anacardiaceae. Similar to poison ivy in that it has three leaflets, grows as a shrub or vine and produces dermatitis in man. Interbreeds with poison ivy. Habit. Western North America from southern British Columbia to northern Baja California. Constit. Poisons presumably closely related if not identical to those in poison ivy.
Toxicodendron quercifolium (Michx.) Greene, Anacardiaceae. Differs significantly from poison ivy. Never climbs or produces aerial roots and rarely hybridizes with poison ivy. Habit. Southern New Jersey to Florida, west to eastern Texas and Kansas. Constit. Poisons may be the same as in poison ivy or Western poison oak.
Extract as antiallergic (hyposensitization therapy).
Poison Oak Extract: Antiallergic (Hyposensitization Therapy)