Sugar Apple (Annona squamosa).

Sugar Apple - Annona squamosa

Annona squamosa is a small, well-branched tree or shrub from the family Annonaceae that bears edible fruits called sugar-apples or sweetsops. It tolerates a tropical lowland climate better than its relatives Annona reticulata and Annona cherimola (whose fruits often share the same name) helping make it the most widely cultivated of these species. Annona squamosa, the custard apple, is an attractive, slow-growing deciduous shrub or small tree with a rounded or spreading, open crown. It reaches a height of 3 - 6 metres.

The sugar apple tree ranges from 10 to 20 ft (3-6 m) in height with open crown of irregular branches, and some-what zigzag twigs. Branches with light brown bark and visible leaf scars; inner bark light yellow and slightly bitter; twigs become brown with light brown dots (lenticels – small, oval, rounded spots upon the stem or branch of a plant, from which the underlying tissues may protrude or roots may issue). Thin, simple, alternate leaves occur singly, 5 centimetres to 17 centimetres  long and 2 centimetres to 6 centimetres wide; rounded at the base and pointed at the tip (oblong-lanceolate). Pale green on both surfaces and mostly hairless with slight hairs on the underside when young, aromatic when crushed.. The sides sometimes are slightly unequal and the leaf edges are without teeth, inconspicuously hairy when young. Leaf stalks are 0.4 centimetres to 2.2 centimetres long, green, and sparsely pubescent.

Solitary or in short lateral clusters of 2–4 about 2.5 centimetres (0.98 in) long, greenish-yellow fragrant flowers on a hairy, slender 2 centimetres (0.79 in) long stalk. Three green outer petals, purplish at the base, oblong, 1.6 centimetres to 2.5 centimetres long, and 0.6 centimetres to 0.75 centimetres wide, three inner petals reduced to minute scales or absent. Very numerous stamens; crowded, white, less than 1.6 centimetres long; ovary light green. Styles white, crowded on the raised axis. Each pistil forms a separate tubercle (small rounded wartlike protuberance), mostly 1.3 centimetres to 1.9 centimetres long and 0.6 centimetres to 1.3 centimetres wide which matures into the aggregate fruit.

Flowering occurs in spring-early summer and flowers are pollinated by nitidulid beetles. Its pollen is shed as permanent tetrads.

Aggregate and soft fruits form from the numerous and loosely united pistils of a flower which become enlarged and mature into fruits which are distinct from fruits of other species of genus (and more like a giant raspberry instead).

The round or heart-shaped greenish yellow, ripened aggregate fruit is pendulous on a thickened stalk; 5 centimetres to 10 centimetres in diameter with many round protuberances and covered with a powdery bloom. Fruits are formed of loosely cohering or almost free carpels (the ripened pistels).

The pulp is white tinged yellow, edible and sweetly aromatic. Each carpel containing an oblong, shiny and smooth, dark brown to black, 1.3 centimetres 1.6 centimetres long seed. There may be a total of 20 to 38, or perhaps more, seeds in the average fruit. Some trees, however, bear seedless fruits.

The original home of the sugar apple is unknown. It is commonly cultivated in tropical South America, not often in Central America, very frequently in southern Mexico, the West Indies, Bahamas and Bermuda, and occasionally in southern Florida. In Jamaica, Puerto Rico, Barbados, and in dry regions of North Queensland, Australia, it has escaped from cultivation and is found wild in pastures, forests and along roadsides.

The Spaniards probably carried seeds from the New World to the Philippines and the Portuguese are assumed to have introduced the sugar apple to southern India before 1590. It was growing in Indonesia early in the 17 th century and has been widely adopted in southern China, Queensland, Australia, Polynesia, Hawaii, tropical Africa, Egypt and the lowlands of Palestine. Cultivation is most extensive in India where the tree is also very common as an escape and the fruit exceedingly popular and abundant in markets. The sugar apple is one of the most important fruits in the interior of Brazil and is conspicuous in the markets of Bahia.

The sweet and creamy fruits are highly regarded as a dessert fruit. They can also be used to make sherbet, ice cream, jellies etc. The fruit is up to 10cm in diameter.

The ripe sugar apple is usually broken open and the flesh segments enjoyed while the hard seeds are separated in the mouth and spat out. It is so luscious that it is well worth the trouble. In Malaya, the flesh is pressed through a sieve to eliminate the seeds and is then added to ice cream or blended with milk to make a cool beverage. It is never cooked.

Leaves, shoots, bark and roots have been reported to have medicinal properties. In India the crushed leaves are sniffed to overcome hysteria and fainting spells; they are also applied on ulcers and wounds and a leaf decoction is taken in cases of dysentery. Throughout tropical America, a decoction of the leaves alone or with those of other plants is imbibed either as an emmenagogue, febrifuge, tonic, cold remedy, digestive, or to clarify the urine. The leaf decoction is also employed in baths to alleviate rheumatic pain. An oil distilled from the leaves is applied to the head for treating sleeplessness. The green fruit, very astringent, is employed against diarrhea in El Salvador. In India, the crushed ripe fruit, mixed with salt, is applied on tumors. The bark and roots are both highly astringent. The bark decoction is given as a tonic and to halt diarrhea. The root, because of its strong purgative action, is administered as a drastic treatment for dysentery and other ailments.

The seeds are acrid and poisonous. Bark, leaves and seeds contain the alkaloid, anonaine. Six other aporphine alkaloids have been isolated from the leaves and stems: corydine, roemerine, norcorydine, norisocarydine, isocorydine and glaucine. Aporphine, norlaureline and dienone may be present also. Powdered seeds, also pounded dried fruits serve as fish poison and insecticides in India.

A paste of the seed powder has been applied to the head to kill lice but must be kept away from the eyes as it is highly irritant and can cause blindness. If applied to the uterus, it induces abortion. Heat-extracted oil from the seeds has been employed against agricultural pests. Studies have shown the ether extract of the seeds to have no residual toxicity after 2 days. High concentrations are potent for 2 days and weaken steadily, all activity being lost after 8 days. In Mexico, the leaves are rubbed on floors and put in hen's nests to repel lice.

Source:
https://en.wikipedia.org/wiki/Annona_squamosa
https://hort.purdue.edu/newcrop/morton/sugar_apple.html