Amaranthus dubius is belongs to the economically-important plant family Amaranthaceae. It is known by common names such as spleen amaranth.
Unlike grain amaranths, this species is eaten as a leafy vegetable.
It flowers from summer to fall in the tropics, but can flower throughout the year in subtropical conditions. It is usually found in waste places or disturbed habitats. It was introduced into Florida, the West Indies, South America, and naturalized locally in Europe, Asia, and Africa.
Amaranthus dubius is considered to be a morphologically deviant allopolyploid. It is very close genetically to Amaranthus spinosus and other Amaranthus species. It is believed to be an ancient hybrid of Amaranthus spinosus with either Amaranthus hybridus or Amaranthus quitensis.