Ludwigia (plant)

Ludwigia (primrose-willow, water-purslane, or water-primrose) is a genus of about 82 species of aquatic plants native to Central and South America with a cosmopolitan but mainly tropical distribution.
At current, there is much debate among botanists and plant taxonomists as to the classification of many "Ludwigia" species. Botanists from the US Department of Agriculture are currently doing genetic analyses on plants from the Western US and South America to better classify members of this genus.
The genus was named by Carl Linnaeus after Christian Gottlieb Ludwig (1709-1773), a German botanist, who was apparently not amused by this honour.
Fossil record.
A large number of fossil seeds of †"Ludwigia collinsoniae" and †"Ludwigia corneri" have been described from middle Miocene strata of the Fasterholt area near Silkeborg in Central Jutland, Denmark.
Selected species.
Listed from the NCBI database: