If you were to toss some cuttings of oxygenating, submerged aquatics on a bare, lined pond they would float about. They might get mushy with surface coating algaes, Winter freezes turn them to mush in cold climates where they freeze in ice

Given a longish growing season, they would try to grow, mass up, and extend their stems downwards, putting out roots....

Anacharis can reach four, five, six feet downwards, their roots would intermesh with leaves and pond debris, they would anchor themselves... over time their roots would make a living blanket at the pond bottom. Cabomba likewise, will push stems downwards, putting out roots whose sole task is to knot, mesh, grip anything they can, if only itself and other roots....

Hornwort won't, it does not make roots, but it would send its stems into deeper water. Winter freezes encourage it to break into fragments which sink to the bottom of the pond, to restart when next growing temps warm the pond

Many aquatic plants are very adaptive, according to the growing conditions that they find themselves

Regards, andy
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