Since it was consistently recovered in three independent lineages, it has been sunk into Pontederia, together with Monochoria.

Eichhornia is pantropical, centered in South America but with P. natans being endemic to continental Africa and Madagascar.

It was named in honour of Friedrich Eichhorn [de], an early-19th-century Prussian minister of education.

[2] Its species are perennial aquatic plants (or hydrophytes) with prostrate and densely branched stems.

The inflorescences can have one to 30 conspicuously attractive flowers, mostly lavender to pink in colour, rarely white.