Elodea crispa is also commonly called pondweed or goldfish weed. It has stiff, tightly-curled leaves and can grow up to two feet in length. The leaves are often eaten by fish and several bunches have been added to the Pnod for their benefit.
Hornwort (Ceratophyllum demersum) is a very attractive plant in both ponds and aquaria. It grows in long, soft, plumed fronds which can reach two feet in length. This was one of the first plants added to the Pnod and grows in abundance.