Sagittaria cuneata

Anyone ever keep this in an aquarium? I had some volunteers show up in my pond, and they seed and I get babies everywhere, so I wanted to try it. I assume they probably put out immersed foliage when they're grown underwater? If it gets kinda tall, it might be cool.

Never kept that one, but I have some outdoor tubs with Sag. graminea or weatherbiana (i think)?  In fall/winter they grow strap-leaves underwater, and in spring-summer they grow emergent spatulate-leaves and flower stalks.  Not sure if temp or photoperiod is more important in triggering the change, but I'm guessing a short photoperiod (10 hrs) might help keep them in the underwater growth form in an aquarium.

Well i grabbed two seedling and put them in there, and they seem to be doing fairly well. No melting leaves yet anyway, and they're even growing. The growth is definitely submersed looking, like a much larger version of subulata, pointed strap like leaves. Bigger though, they're already at about 3" and about 1/4" wide. These are also from seed, still have the husk on the roots. That could help, since they'll acclimate in the aquarium rather than in a colder pond. We'll wait and see.