blueweed

from The Century Dictionary.

• noun The viper's bugloss, Echium vulgare, a foreign weed with showy blue flowers which has been introduced into the United States.
• noun A cæsal piniaceous plant, Hoffmanseggia stricta, introduced from Mexico into Texas in alkali soils and regarded as a pest, though its tubers are eaten by hogs and its foliage, in dry seasons, by cattle. It is the camote del raton of the Mexicans.

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

• noun a coarse prickly European weed (Echium vulgare) with spikes of blue flowers; naturalized in the U. S.

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

• noun a coarse prickly European weed with spikes of blue flowers; naturalized in United States