many Potamogeton spec. (Pondweeds)
Lysimachia nummularia
Ceratophyllum demersum (Hornwort)
Anagalis Tenella (Bog Pimpernel, can do submersed, if you can find it, lovely little plant)
Elodea
Cabomba caroliniana (can do)
Even some Rotala's dont mind colder temperatures, still got the Rotala Indica and something like a Colorata growing in the pond outside today and doing well.
Also some Myriophyllums (Watermilfoil) dont mind, like Myriophyllum aquaticum (Parrot feather) is native to brasil but nowadays found all over the world. Its sister the Brasiliensis also can do.
Im forgetting a few already discussed here at ukaps..
Most actualy tropical spec which can do, will grow much slower, thus more suspectible to catching dirt like algae.. If you plan to keep 'm with gold fish piggy's
clean very well or they certainly will catch lot of diatoms.
I guess there are many more.. Its trail and error..
Look in the pond shops, lots of what is sold there can do submersed as well, in the case it will most likely be labelled suitable as oxygenating plant for pond..