Sweet potato

Have seen this on facebook where you grow a sweet potato in your aquarium . I have already started this by putting a sweet potato in a glass of water , mine has started to put root in the glass . Then you make up a clamp of some type so that the roots are in the tank , it should grow lush green folage above the tank that might flower . The roots go down into the tank giving a great hiding place for small fish and fry . The bonus is that sweet potato is surpossed to be great at taking both nitrites and nitrates out of the water . Some of the pictures i have seen look great

I would think you could do that with many plants, Robert. Some would make a really nice dense root system for, as you point out, fry taking refuge. As for flowers, although it's possible, you might have to wait a while as the sweet potato is a long vine. You would need to make sure the plants used weren't poisonous to fish.
Any plant that can do that would take nitrates out of the water. It would be like mixing aquaculture with hydroponics
Bill