in botany, a genus of the syngenesia polygama aquatilis clasps. The receptacle is peltateaceous; the pappus has erect scabrous awns; and the calyx is imbricated. There are thirteen species, only three of which, viz. the tripartita or trifid water-hemp agrimony, the cornua or whole-leaved water-hemp agrimony, and the minima or least water-hemp agrimony, are natives of Britain. The leaves of the bidens are recommended for strengthening the tone of the visera, and as an aperient; and said to have excellent effects in the dropsy, jaundice, catarrhies, and scorbutic disorders.