"Altum" wrote in news:1150935666.484145.179650
@y41g2000cwy.googlegroups.com:

gave me some cuttings. I've got a floating, elodea-like plant and some

That's probably Elodea canadensis... it's all over the place at the cottage
and in most lakes, bays, and beaches. It's not a true floating plant--as
it has true roots not rhizoids--but it survives very well floating.

Keep in mind that collecting wild plants from public waterways is probably
illegal, so have a look around for any wildlife officials before you start
harvesting. These laws are in place to prevent the commercial exploitation
of native wildlife so no one is going to raise a fuss unless you start
selling it.