water fern
noun
1
- a small aquatic or semiaquatic fern which is either free-floating or anchored by the roots, found chiefly in tropical and warm countries水蕨。
1.1
- Families Azollaceae, Marsileaceae and Salviniaceae: many species, in particular the minute floating Azolla filiculoides of tropical America, which has been naturalized elsewhere.满江红科、苹科和槐叶苹科：多种, 尤指美洲热带地区的细小漂浮的细叶满江红, 已在其他地方移植成功。
2
- an Australian fern with large coarse fronds, typically growing in marshy areas and rainforests澳大利亚乌毛蕨。
2.1
- Genus Blechnum, family Blechnaceae: several species.乌毛蕨属, 乌毛蕨科：数种。