amorpha

from WordNet (r) 3.0 (2006)

amorpha
    n 1: any plant of the genus Amorpha having odd-pinnate leaves
         and purplish spicate flowers

from The Collaborative International Dictionary of English v.0.48

Amorpha \A*mor"pha\, n.; pl. {Amorphas}. [Gr. ? shapeless.]
   (Bot.)
   A genus of leguminous shrubs, having long clusters of purple
   flowers; false or bastard indigo. --Longfellow.
   [1913 Webster]