virgin's bower

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Any of several climbing clematises, especially Clematis virginiana, of eastern North America, having clusters of white flowers and feathery seed heads.

from The Century Dictionary.

• noun A name of several species of Clematis, primarily the European C. Vitalba, the traveler's-joy, also called old-man's-beard, and sometimes hedge-vine, maiden's-honesty, smokewood.

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

• noun common climber of eastern North America that sprawls over other plants and bears numerous panicles of small creamy white flowers