Green Water Celery Oenanthe
japonica
Water Celery is a staple in any pond in my humble opinion.
Fish love to eat this plant and it is a great source of vitamins for fish. Grow lots so you have a constant supply.
I always recommend growing one outside of the pond and switching the 2 back and forth as the fish eat the leaves.
The do not eat the stems only the soft leafy part of the plant.
It will grow back new leaves once it is removed from the pond and put in a bucket of water that has some fertilizer added to the water.
Some even use the leaves in salads and soups. Yes, it is edible for human consumption.
The green Water Celery grows about 2' tall and has tiny white flowers that form in July and August.
Sunny
is enjoys grazing the water celery
Hardy Zone 6 or higher