Mareca is a genus or subgenus of duck in the family Anatidae that includes the wigeons. The species now placed in this genus were formerly placed in the genus Anas. A molecular phylogentic study comparing mitochondrial DNA sequences published in 2009 found that the genus Anas, as then defined, was non-monophyletic. Based on the published phylogeny, the genus Anas was split into four monophyletic genera with five extant species moved into the resurrected genus Mareca.