Amaranthus L., Sp. Pl. 1: 989. 1753 sec. Townsend (1993)
  • =Acnida L., Sp. Pl. 2: 1027. 1753 syn. sec. Townsend (1993)
  • Amaranthus subg. Acnida (L.) Aellen ex K.R.Robertson in J. Arnold Arbor. 62(3): 283. 1981 syn. sec. Townsend (1993)
  • =Albersia Kunth, Fl. Berol. 2: 144. 1838 syn. sec. Townsend (1993)
  • Amaranthus subg. Albersia (Kunth) Gren. & Godr., Fl. France 3: 3. 1856 syn. sec. Townsend (1993)
  • =Acanthochiton Torr., Rep. Exped. Zuñi & Colorado Rivers: 170. 1853 syn. sec. Townsend (1993)
  • Amaranthus sect. Acanthochiton (Torr.) Mosyakin & K.R.Robertson in Ann. Bot. Fenn. 33: 277. 1996 syn. sec. Townsend (1993)
  • =Goerziella Urb. in Repert. Spec. Nov. Regni Veg. 20: 301. 1924 syn. sec. Townsend (1993)
  • Amaranthus sect. Goerziella (Urb.) Mosyakin & K.R.Robertson in Ann. Bot. Fenn. 33: 280. 1996 syn. sec. Townsend (1993)


The genus, with its more than 75 currently recognized species, is monophyletic and constitutes a C4 lineage (Sage & al. 2007) within the otherwise completely C3 amaranthoid clade (Müller & Borsch 2005b) of subfamily Amaranthoideae. The current infrageneric system of the genus (Mosyakin & Robertson 1996, 2003), recognizing three subgenera (subg. Amaranthus, subg. Acnida (L.) Aellen ex K.R.Robertson, and subg. Albersia (Kunth) Gren. & Godr.) and several sections, was developed before the advent of molecular phylogenetic methods and is now in need of revision. Subg. Acnida, represented by dioecious species currently placed in three sections, seems to be non-monophyletic, since dioecy in Amaranthus probably developed independently at least twice (Mosyakin 2005). Surprisingly, no comprehensive molecular phylogenetic study of Amaranthus has been done yet, despite the economic importance of the genus, containing some pseudocereal and green crops, popular ornamentals, and noxious weeds.