A creeping grass-like aquatic fern which has slender stem-like shoots with small globular spore-producing bodies at their bases, growing on the muddy margins of ponds and lakes in western Europe.
- Pilularia globulifera, family Marsileaceae
More example sentences
- In Cumbria we are looking for volunteers to help carry out a survey for two unusual Back from the Brink rarities - marsh clubmoss and pillwort.
- Austral Pillwort is at first appearance a very unfern-like, semi-aquatic fern, resembling more a small fine grass.