The Nipple plant also known as the Cows Udder plant is a hardy perennial with large velvety leaves, small purple flowers and firm thorns. Its showy yellow nipple shaped fruit is related to the tomato. Unlike the tomato however, it's quite poisonous. It does have some medicinal properties though and can also be used as a detergent for washing clothes. The fruit can even last up to two months which is a long time in relation to fruits. It is native to South America.