richweed

from WordNet (r) 3.0 (2006)

richweed
    n 1: erect perennial strong-scented with serrate pointed leaves
         and a loose panicle of yellowish flowers; the eastern
         United States [syn: {horse balm}, {horseweed}, {stoneroot},
         {stone-root}, {richweed}, {stone root}, {Collinsonia
         canadensis}]
    2: a plants of the genus Pilea having drooping green flower
       clusters and smooth translucent stems and leaves [syn:
       {richweed}, {clearweed}, {dead nettle}, {Pilea pumilla}]

from The Collaborative International Dictionary of English v.0.48

Richweed \Rich"weed`\, n. (Bot.)
   An herb ({Pilea pumila}) of the Nettle family, having a
   smooth, juicy, pellucid stem; -- called also {clearweed}.
   [1913 Webster]