Amaranthus greggii is also known as Gregg's amaranth or Josiah amaranth. It is a glabrous annual flowering plant native to Texas, Louisiana, and Mexico. The plant can grow up to 1 m (3 ft) in height. It is found in sand dunes and near sea beaches. The species name greggii honors Josiah Gregg (1806 – 1850), a merchant, explorer, naturalist, and author of the American Southwest and Northern Mexico.