Definition of water willow in US English:

water willow


  • 1Any willow (genus Salix) that typically grows close to water, as (in Europe) the osier, S. viminalis, and white willow, S. alba, and (in North America) black willow, S. nigra.

  • 2Chiefly North American. Either of two herbaceous perennials that typically grow in shallow water at stream or pond margins: (a) (more fully "American water willow") Justicia americana (family Acanthaceae); (b) swamp loosestrife, Decodon verticillatus (family Lythraceae). Also: any other plant of the genus Justicia, found mainly in tropical and subtropical America.


Late 16th century; earliest use found in Leonard Mascall (d. 1589), translator and author. From water + willow.


water willow

/ˈwɔːtə ˌwɪləʊ/