Looking for extremely thirsty plants - pond plants appropriate?

by Dawn
(Annapolis, MD)

We have spots in our backyard that get standing water for days following a heavy enough rain. Are there uber thirsty plants that will soak this up, and rely on us for heavy watering at other times? We are willing to water during rainless weeks, but would love a plant that drinks rain like the dickens on its own.

So far, only the Weeping Willow tree seems to fit the bill, but we've heard that is a dangerously invasive plant, and part of the area we need to plant in is over our well.

Thanks for any thoughts.

Doug says that the perennials and plants listed on my water garden website are excellent plants for wet places. I'm not sure any of them "soak up" water but they all thrive in damp soils.