Request: Cold water plants


I am sending this request on behalf of a friend who is not yet online.

If anyone could give us some information about plants that would be 
suitable for this environment it would be much appreciated.

The environment:

A shallow pond (4 ft at center, approximately 15 ft in diameter) in 
partial sun, partial shade.

The pond is fed by an everflowing spring the temperature of which is 
about 57 degrees F.

The location is Fayetteville, Arkansas, where summer days are very humid 
and can be in the high 90s and low 100s through July and August.

My friends have had poor luck trying to populate their pond with aquatic 
plants. They think the coolness of the pond and the high air 
temperature are the problem. Watercress, however, thrives and they have to 
weed it out frequently or it chokes the pond. 

Any suggestions from the list's experienced gardeners are appreciated! 
Thank you all!

Cordah E. Robinson
Digital Presentation and MultiMedia Specialist
Indiana University ISS/UCS Teaching and Learning Technologies Laboratory
Ballantine 307   812.855.7829  Bloomington, IN  47405-6601
Wrubel Computing Center  812.855.0386