Amaranthus

Amaranthus is a genus of flowering plants in the amaranth family Amaranthaceae. It comprises about 60 to 70 species of annuals and short‑lived perennials, with a cosmopolitan distribution across warm temperate and tropical regions. Plants are herbaceous with simple, alternate leaves and erect stems. The inflorescences are dense panicles that bear numerous small flowers and are often conspicuously colored in red, green, or purple.

Many species are grown as leafy vegetables or ornamentals; others are important grain crops. Amaranthus retroflexus, commonly called redroot pigweed, is a widespread weed. Grain amaranths—predominantly Amaranthus cruentus, Amaranthus hypochondriacus, and Amaranthus caudatus—have been cultivated since pre-Columbian times in the Americas and are grown in various regions today. The seeds are high in protein and lysine and are used as a pseudocereal; leaves are cooked as greens in many cuisines.

Ornamental amaranths are valued for their showy flower clusters, which can form long hanging plumes or upright spikes depending on the cultivar. In cultivation, species are noted for drought tolerance and rapid growth, but some can become persistent weeds due to prolific seed production.