Common names: water sprite, Indian fern, pod fern, swamp fern, phak kuutnam

Family: Pteridaceae (including Parkeriaceae)

Could be confused with: Unlikely to be confused with any other aquatic plant.

Native distribution: Pan-tropical.

Species commonly cultivated:
Ceratopteris cornuta (P. Beauv.) Lepr. (Africa, Madagascar, Asia)
C. pteroides (Hook.) Hieron. (South and Central America, Asia)
C. richardii Brongn. (Africa, Madagascar, Central and South America)
C. thalictroides (L.) Brongn. (Asia, Australia, Africa, America)

Adventive distribution: Ceratopteris thalictroides is introduced into Florida (United States).

Weed status: Information not available.

Habit: Free-floating to attached and emergent herb with finely dissected leaves.

Brief description: Perennial fern. Stem compact, bearing numerous roots and covered with relatively few scales. Leaves in a basal rosette, petiolate, 1- or more-pinnate; lower leaves sterile, often bearing plantlets along leaf margin; upper, emergent leaves fertile, more deeply dissected than lower leaves, bearing sporangia on lower surface, margins inflexed (curled), partially covering sporangia. Dispersal by spores, plantlets and leaf fragments.

Natural habitat: Margins of lakes, rivers, ponds and swamps.

Additional comments: Ceratopteris contains from one to 12 species, but differentiating them can be very difficult due to the high degree of morphological variation and the formation of hybrids where the distributions overlap. The taxonomy of the genus is problematic and some authors refer to several varieties of a single species, C. thalictroides. Ceratopteris richardii is infrequently cultivated for aquaria, but is more commonly used as an experimental ‘model’ organism for studies of plant physiology. Younger leaves are edible.