Waterwort

from The Collaborative International Dictionary of English v.0.48
Waterwort \Wa"ter*wort`\, n. (Bot.)
   Any plant of the natural order {Elatineae}, consisting of two
   genera ({Elatine}, and {Bergia}), mostly small annual herbs
   growing in the edges of ponds. Some have a peppery or acrid
   taste.
   [1913 Webster]
    

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