markweed

from The Century Dictionary.

• noun The poison-ivy, Rhus radicans.

from the GNU version of the Collaborative International Dictionary of English.

• noun A climbing plant (Toxicodendron radicans) common in eastern and central U. S. with ternate leaves and greenish flowers followed by white berries. It yields an irritating oil that causes a rash on contact; commonly called poison ivy.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun climbing plant common in eastern and central United States with ternate leaves and greenish flowers followed by white berries; yields an irritating oil that causes a rash on contact