WordNet sense 1 (foul-smelling perennial Eurasiatic herb with a green creeping rhizome):

hedge nettle, Stachys sylvatica

WordNet sense 2 (coarse bristly Eurasian plant with white or reddish flowers and foliage resembling that of a nettle; common as a weed in United States):

hemp nettle, Galeopsis tetrahit

WordNet sense 3 (a plants of the genus Pilea having drooping green flower clusters and smooth translucent stems and leaves):

clearweed, richweed, Pilea pumilla