Amaranthus australis is also known as southern amaranth or southern water-hemp. The plant usually grows from 1to in height, though some have been known to grow up to 9m (30feet) high. The stems can be up to 30 cm in diameter. It is a herbaceous annual. It is found in many southern states of the United States, Mexico, the West Indies, and South America. They are frequently found in wetland areas. It is herbaceous, short lived perennial. The largest is 4.6m (15.1feet) tall.