A tropical shrub in the Sapotaceae with glossy, dark green foliage and smallish, bright red fruits that have a strange effect when eaten: although they taste rather bland themselves, a substance they contain binds to the taste buds on your tongue and causes all acidic foods (such as lemons and limes) eaten for up to an hour afterwards to taste wonderfully sweet. The fruit is used as a natural sweetener in Japan and Africa, but attempts to bring it to wider use in the West seem to have been thwarted by the sugar industry. Although native to tropical lowland areas in western Africa, the plant is adaptable to a range of frost-free climates. It requires acid soil and will not thrive on limestone. It can also be grown as a house plant.