See text Pontederiaceae is a family of flowering plants.

[1][2] It is a small family of heterostylous aquatic plants, occurring in tropical and subtropical waters.

Charles Darwin was interested in the specialized form of heterostyly found in the family, known as tristyly.

[3][4] It is best known for the water hyacinth (Pontederia crassipes), which is an invasive species in many waterways.

The highly modified Heteranthera gardneri is a submerged aquatic with a two-flowered pseudanthium.