amaranth [Gr.,=unfading], common name for the Amaranthaceae (also commonly known as the pigweed family), a family of herbs, trees, and vines of warm regions, especially in the Americas and Africa. The genus Amaranthus includes several widely distributed species called amaranths that are characterized by a lasting red pigment in the stems and leaves. They have been a poetic symbol of immortality from the time of ancient Greece. Amaranthus also includes such weeds as the green amaranth, A. retroflexus, and various species commonly called tumbleweed and pigweed, as well as several cultivated plants—e.g., love-lies-bleeding, or tassel flower, and Joseph's coat. Other ornamentals in the family are the globe amaranth (genus Gomphrenia), sometimes called bachelor's button, and the cockscomb (Celosia), both originally tropical annuals. They can be preserved dry and are used in everlasting bouquets. Amaranth is classified in the division Magnoliophyta, class Magnoliopsida, order Caryophyllales.