Question?? Concerning plants for an outdoor pond

I would like some suggestions on plant species to place in a pond.  The pond will be placed in a climate with moderate summers (27oC - 32oC) and fairly cold winters (-5oC - -15oC).  I'm looking for something that will oxygenate the pond while providing a possible food source for carp.  The pond will allowed to go wild so I need something hardy.  Any suggestions???