A friend has asked the following elsewhere, and I figured that here would be a good place to ask for assistance:
We have an area of garden that used to be the village pond, so there's quite a dip that we can't really do a lot with. In heavy weather, it floods. A pond isn't exactly a great option because the liner would seal the ground underneath so the flooded area would just get nearer to the house. When it happens, it's usually not for long, although it did flood and then freeze this winter so the birds had their own private ice rink.
So my question is, what shubs could I plant in that area that will put up with standing water? It's about 20 feet across so I might as well make a feature of the area. It gets pretty much full sun all day.