Vanilla planifolia is a species of vanilla orchid. It is native to Mexico, Guatemala and Belize. It is one of the primary sources for vanilla flavouring, due to its high vanillin content. Common names include flat-leaved vanilla,and West Indian vanilla. Often, it is simply referred to as "the vanilla". Flowers are greenish-yellow, with a diameter of 5 cm (2 in). They last only a day, and must be pollinated manually, during the morning, if fruit is desired. The plants are self-fertile, and pollination simply requires a transfer of the pollen from the anther to the stigma. If pollination does not occur, the flower is dropped the next day. Fruit is produced only on mature plants, which are generally over 3 m (10 ft) long. The fruits are 15–23 cm (6–9 in) long pods (often incorrectly called beans). Outwardly they resemble small bananas. They mature after about five months, at which point they are harvested and cured. Curing ferments and dries the pods while minimizing the loss of essential oils. Vanilla extract is obtained from this portion of the plant.