It may be native to the Neotropics[7] or Central and Eastern North America,[8] but is widespread as an introduced species on most continents in a great number of habitats.

[9] No species of genus Amaranthus is known to be poisonous to humans,[10] but the leaves of A. retroflexus contain oxalic acid and may contain nitrates if grown in nitrate-rich soils.

[11] Like many other species of Amaranthus, this plant may be harmful and even deadly when fed to cattle and pigs in large amounts over several days.

[11] A. retroflexus was used for a multitude of food and medicinal purposes by many Native American groups in the western United States.

It is used in the Indian state of Kerala to prepare a popular dish known as thoran by combining the finely cut leaves (cheera ) with grated coconut, chili peppers, garlic, turmeric and other ingredients.