The calabash, bottle gourd, or white-flowered gourd, Lagenaria siceraria (synonym Lagenaria vulgaris Ser.), also known as opo squash or long melon, is a vine grown for its fruit, which can either be harvested young and used as a vegetable, or harvested mature, dried, and used as a bottle, utensil, or pipe. The fresh fruit has a light-green smooth skin and a white flesh. Rounder varieties are called calabash gourds. They grow in a variety of shapes: they can be huge and rounded, small and bottle shaped, or slim and serpentine, more than a metre long. Because bottle gourds are also called "calabashes", they are sometimes confused with the hard, hollow fruits of the unrelated calabash tree, Crescentia cujete, whose fruits are also used to make utensils, containers, and musical instruments. The gourd was one of the first cultivated plants in the world, grown not primarily for food, but for use as water containers. The bottle gourd may have been carried from Africa to Asia, Europe, and the Americas in the course of human migration, or by seeds floating across the oceans inside the gourd. It has been proven to be in the New World prior to the arrival of Christopher Columbus.