DT wrote Watercress, maybe?
I have watercress growing in my waterfall.
DH weeded it back to one sprig this spring and
it grew in completely again.
I've been tossing bunches of it in the
pond for the fish, they love it.
I've also used it in salads and on sandwiches
for us.
k30a
and the watergardening labradors
http://www.geocities.com/watergarden...dors/home.html