Not real potatoes silly

Ornamental Potatoe Vines. They are not poisonous according to any list I've ever found and my koi munched on them casually without any problems
KFG, They will come back unless it gets toooooo cold. We dig the roots (which look like a blonde yam), let them dry out about a week, wrap'em up and put them in the spare refrigerator over the winter. The roots they put down in the water will only be at the edges and you can easily pull them to the top of the bank when you pull your ponds.