poison-ivy

See also: poison ivy

English

Etymology

poison +‎ ivy

Noun

poison-ivy (uncountable)

1. A woody vine plant in the family Anacardiaceae (Toxicodendron radicans or Rhus toxicodendron), well-known for its ability to produce urushiol, a skin irritant that causes an itching rash for most people.

Usage notes

Although usually written as poison ivy, the name is often spelled "poison-ivy" to indicate that it is not a true Ivy or Hedera.