1) Collinsonia canadensis 2) Herb 3) Herbaceous plant 4) Horse balm 5) Horseweed 6) Stone root 7) Stoneroot 8) The eastern United States Found on https://www.crosswordclues.com/clue/richweed
Rich'weed` noun (Botany) An herb ( Pilea pumila ) of the Nettle family, having a smooth, juicy, pellucid stem; -- called also clearweed . Found on http://www.encyclo.co.uk/webster/R/79