What is Amaranthus dubius

Usually it grows to a size of 80-120 cm. It has both green and red varieties, as well as some with mixed colors. The green variety is practically undistinguishable from Amaranthus viridis.
It flowers from summer to fall in the tropics, but can flower throughout the year in subtropical conditions. It is a ruderal species, usually found in waste places or disturbed habitats.
Amaranthus dubius is considered to be a morphologically deviant allopolyploid. It is very close genetically to Amaranthus spinosus and other Amaranthus species.