Pontederiaceae (weeds)
From Pestinfo-Wiki

Eichhornia crassipes flowers (click on image to enlarge it)
Author(s): Jim Conrad
Source: Wikimedia Commons
Author(s): Jim Conrad
Source: Wikimedia Commons
Pontederiaceae (weeds) - (water-hyacinth family)
This is a small family of aquatic plants containing around 30 species. These grow in the tropics and subtropics. They are either free floating or anchored to the bottom. The leaves are lanceolate to broad and heart-shaped. Some species are kept as ornamentals, however, several are invasive and important weeds like Eichhornia crassipes or Monochoria vaginalis.
The following genera are currently entered under this family: