There is a lot of stuff you can get to grow in low wet areas as long as it doesn't get submerged often. I would recommend first though that you get a soil test done... Any farming supply store or lawn and garden store should do it or steer you in the right direction on where to get it done. I work for a Farming Co-Operative and I have done lots of soil testing. The areas close to swamps are usually very very fertile, but the soil gets very acidic because of all the leaves and decay in it. So I am sure you will have to spread some lime before you put out anything. It takes a while for that lime to break down to be effective (usually a few months at least) so the sooner you can get it tested the better!! Otherwise you will throw out your seed and not get much of a stand of anything...

rye grass

rice should do well