These interesting tropical, aquatic Ferns are found in ponds and lakes in many parts of the world, including North America. C. pteridoides, the Floating Fern, is an edible plant from South America. It is found growing wild in Florida, along the Gulf Coast of Mississippi and Louisiana. This plant produces rosettes of pale green, floating, sterile fronds that are buoyed up with internal air pockets. Taller, much-divided, larger, fertile fronds stand upright in the center of these.
Viviparous buds form in the notches of the leaf margins.
C. thalictroides, commonly called Water Fern, Water Sprite, or Water Hornfern, is a native to Madagascar and eastern Asia. This species is grown in Japan as a spring vegetable. This plant sometimes roots into the mud. Buds form in the notches of the fertile fronds and produce new plantlets. In cool regions, they may be wintered in a lighted aquarium.