Fig. 24: The ilama (Annona daversifolia), as grown in southern Florida, has a thick rind and dryish flesh.
The tree may be spreading or erect, to 25 ft (7.5 m), often branching from the ground. It has aromatic, pale brownish-gray, furrowed bark and glossy, thin, elliptic to obovate or oblanceolate leaves, 2 to 6 in (5-15 cm) long. There are 1 or 2 leaflike, nearly circular, glabrous bracts, 1 to 1 3/8 in (2.5 3.5 cm) long, clasping the base of the flowering branchlets. The new foliage is reddish or coppery. Solitary, long-stalked, maroon flowers, which open to the base, have small rusty hairy sepals, narrow, blunt, minutely hairy outer petals, and stamen-like, pollenbearing inner petals. The fruit is conical, heart-shaped, or ovoid globose, about 6 in (15 cm) long; may weigh as much as 2 Ibs (0.9 kg). Generally, the fruit is studded with more or less pronounced, triangular protuberances, though fruits on the same tree may vary from rough to fairly smooth. The rind, pale-green to deep-pink or purplish, is coated with a dense, velvety gray-white bloom. It is about 1/4 in (6 mm) thick, leathery, fairly soft and granular. In green types, the flesh is white and sweet; in the pink types, it is pink-tinged near the rind and around the seeds, all-pink or even deep-rose, and tart in flavor. It is somewhat fibrous but smooth and custardy near the rind; varies from dryish to fairly juicy, and contains 25 to 80 hard, smooth, brown, cylindrical seeds, 3/4 in (2 cm) long, 3/8 in (1 cm) wide, each enclosed in a close-fitting membrane easily slipped off when split.
Origin and Distribution
The ilama is native and grows wild in foothills from the southwest coast of Mexico to the Pacific coast of Guatemala and El Salvador. The earliest known record of the fruit was made by Francisco Hernandez who was sent by King Philip II of Spain in 1570 to take note of the useful products of Mexico. For many years, it was confused with either the soursop or the custard apple.
The United States Department of Agriculture introduced seeds from El Salvador in 1914 (P.I. No. 35567); from Guatemala in 1917 (P.I. No. 45548); and from Mexico in 1919, 1922 and 1923 (P.I. Nos. 46781, 55709, and 58030). One of the trees planted at the Plant Introduction Garden, Miami, Florida, bore its first fruits in 1923. Several thousand seedlings had been sent to Puerto Rico, St. Croix, various part of tropical America and Asia (including Ceylon), and the Philippines. Apparently few survived. Only in its homeland is the ilama commonly grown in dooryards, occasionally in orchards of 100 trees or more. Dr. Victor Patino took seeds from Mexico to Colombia for planting in the Cauca Valley in 1957. In spite of early enthusiasm for this species, it is seldom mentioned in horticultural literature. In 1942, there were no more than 50 trees in southern Florida, only 3 of bearing age. In 1965, Dr. John Popenoe, Director of Fairchild Tropical Garden, brought seeds from Guatemala and raised a number of seedlings for distribution, but the tree is still quite rare in Florida. It is too tender even for southern California.
One named cultivar, 'Imery', introduced into Florida from El Salvador and grown at the Agricultural Research and Education Center, Homestead, is large and pinkfleshed but not as flavorful as some of the white-fleshed acquisitions from Guatemala.
The ilama is strictly tropical; grows naturally not higher than 2,000 ft (610 m) in Mexico; is cultivated up to 5,000 ft (1,524 m) in El Salvador; up to 5,900 ft (1,800 m) in Guatemala. It seems to do best where there is a long dry season followed by plentiful rainfall. In areas where rainfall is scant, the tree is irrigated.
Dr. Wilson Popenoe observed that the tree was not particular as to soil but should prosper in rich, loose loam. In Florida, it performs better on deep sand than on oolitic limestone.
Ilama seeds, taken from ripe fruits, remain dormant for several weeks or even months and the germination rate thereafter is low. Applications of gibberellic acid at 350 ppm greatly increases germination. Higher concentrations cause malformations in the seedlings. Whip-or cleft-grafting onto custard apple (A. reticulata) rootstocks has been successful. Seedlings begin to bear when 3 to 5 years old.
The harvesting season begins in late June in Mexico and lasts only a few weeks. It extends from late July to September in Guatemala; from July to December in Florida. Traditionally, the fruits are not picked until they have begun to crack open, but they can be picked a little earlier and held up to 3 days to soften. They will not ripen if harvested too early.
The yield is typically low. In Mexico, during the normal fruiting period, some trees will have no fruits, others only 3 to 10; exceptional trees may bear as many as 85 to 100 fruits in a season.
The Ilama is not as susceptible to the chalcid fly as are its more popular relatives in Florida.
Food Value Per 100 g of Edible Portion*
|Ascorbic Acid||13.6 mg|
The early plant explorers of the United States Department of Agriculture and their contacts in Mexico and Central America described the ilama as resembling the cherimoya or atemoya in flavor and expected it to be well received in this country and abroad. However, as grown in Florida, it is not as appealing as the sugar apple. There is a slightly unpleasant flavor close to the rind. The flesh is always consumed raw, either in the half shell or, better still, shallowly scooped out, chilled, and served with a little cream and sugar to intensify the flavor, or with a dash of lime or lemon juice.