The most widely known economic products of the Annonaceae family in the tropics are its edible fruits, especially the fruits of the genus Annona (custard apple). One of the most important of these is Annona reticulata (West Indian bullock’s-heart), which is well adapted to hot climates and produces fruit only three years after planting. The common name is suggestive of the round-to-heart-shaped appearance and size of the fruit, which may be up to 12 cm (5 inches) in diameter and length when ripe. When the fruit is ripe and the yellow-brown skin has begun to blacken, its white to cream-coloured pulp becomes sweet and aromatic, and it resembles ice cream when chilled.

Annona squamosa (sweetsop, or sugar apple), although native to northern South America, Central America, and the Caribbean region, is even more widely cultivated and highly esteemed in India and Pakistan. The conical fruits break into segments when ripe and expose a cream-coloured sweet pulp in which dark brown glossy seeds are embedded. Among the natives of the tropics, the sugar apple tree is reputed to be of medical value. Tea made from the roots is highly purgative, while that made from the leaves is a mild laxative and is also considered to have a general tonic effect on the digestive tract. Poultices of the leaves are used in dressing infected wounds.

The cherimoya is the fruit of a rather small tree, Annona cherimola, which is native to the cool (but frost-free) mountain valleys of Peru and Ecuador. Although it is grown in southern Florida, it does not produce fruit well there because of the high humidity; it is currently commercially grown on a small scale in southern California. The fruits, however, are quite perishable and ferment readily. Like the sugar apple, it is now established in the Old World tropics. Although the fruit does not break into segments when ripe the way that the sugar apple does, the flesh is of a more creamy consistency (it contains up to 18 percent sugar) and has fewer seeds. Under ideal conditions, the fruit may attain a large size, weighing up to 7 kg (16 pounds).

Annona muricata (soursop, or guanabana) also is native to the American tropics; it probably originated in Brazil or the Antilles. In a commercial setting, it must be pollinated by hand. The fruit weighs between 1.3 and 3.6 kg (3 to 8 pounds) and reaches 15 to 20 cm (6 to 8 inches) in length. It is tapering and heart-shaped, and the green skin is covered with spiny protuberances. The aromatic flesh, white and somewhat fibrous, is strained to make custards and ice cream; the acidulous juice is usually extracted to make a refreshing drink, which has been described as a combination of the flavours of strawberries, pineapples, and cinnamon. The fruit is approximately 12 percent sugar, mostly glucose, and is a good source of niacin, riboflavin, and vitamin C. The black seeds contain toxins that have a purported use locally as a repellent against parasites. The hybrid Annona squamosa × cherimola (atemoya) apparently originated in Central America and the Antilles; the fruit contains some of the best features of both parents. Extracts of the root and leaves have a laxative effect, and poultices of the leaves are used to dress infected wounds. Annona glabra (alligator, or pond, apple) grows plentifully in the Florida Everglades and on the Florida Keys, where its fruits have been described as “edible but not very palatable.” The tree’s prime use in Florida is as a rootstock for A. reticulata and A. squamosa when the soil is deep and sandy.

Other species of Annona that produce comparatively inferior fruit but are eaten locally include A. montana (mountain soursop), from the West Indies and South America; A. longiflora, from Mexico; A. paludosa, from Brazil; A. testudinea, from Honduras; A. nutans, from Paraguay; A. senegalensis, from East and West Africa; and A. diversifolia (ilama), which was first cultivated long ago by the Aztecs of Mexico.

Two species of Rollinia (R. mucosa and R. pulchrinervis) have edible fruits that reach 10 cm (4 inches) in length and bear some resemblance to those of the soursop, except that the spines are softer and more blunt. Rollinia mucosa is a large tree native to the West Indies and northern South America, whereas R. pulchrinervis is native to the Amazon River basin. Both species are referred to by the common name biriba, and both are widely cultivated, particularly throughout Brazil, for their delicious fruits.

Asimina triloba (pawpaw) is native to eastern North America and produces edible fruits of various sizes, colours, and palatabilities. (Carica papaya, or papaya, of the family Caricaceae, is also sometimes known as pawpaw.) Two general types of Asimina triloba have been observed: large, yellow-fruited, highly flavoured, and early-ripening; and relatively small, white-fleshed, mild-flavoured, and late-ripening. A number of selected clones (groups of plants of identical genetic makeup that are vegetative divisions of one plant), propagated by grafting, are cultivated, principally in southern Pennsylvania, Ohio, Illinois, and Indiana (where the yellowish fruits are referred to as Indiana bananas). An alcoholic beverage may be made from the fruit.

Chemicals

Cananga odorata (ylang-ylang) ranges from the tropical parts of eastern India through Malaysia to the Philippines. The name of the plant, which means “flower of flowers,” derives from the exceedingly delicate and evanescent fragrance of the yellowish green, bell-shaped flowers. The fragrance is highly valued in the manufacture of perfumes. Ylang-ylang, or cananga, oil is derived by simple distillation from the petals of fully opened flowers. Although the tree blossoms throughout the year, the flowers picked in May or June yield the highest amounts of cananga oil. Long known to the peoples of East Asia, this oil first reached Europe about 1864.

In the upper Amazon region, Indian tribes use an extract from the tree Unonopsis veneficiorum to tip their poison blowgun darts and arrows; this substance has a similar paralyzing effect on humans and other animals to that caused by curare, which is obtained from the genus Strychnos of the family Loganiaceae.