As an ornamental tree, the rose-apple is of value for all tropical and subtropical regions. As a fruit it is beautiful and interesting, but is not much used except for making preserves.
The tree grows to 25 or 30 feet in height, and is shapely and attractive in appearance. The leaves are oblong-lanceolate, acuminate, 5 to 8 inches long, thick and glossy, with the new growth wine-colored. The flowers are produced upon the young branchlets in short terminal racemes. They are greenish white in color and have a conspicuous tuft of long stamens which almost hide the other floral parts from view. The calyx-tube is turbinate, and the corolla composed of four obovate concave petals. The fruit is round or oval, 1 to 2 inches in length, and crowned at the apex with the calyx-segments. In color it is whitish green to apricot-yellow; it is perfumed with the odor of the rose, and is attractive in appearance. The flesh is crisp, juicy, and sweet. The single, round seed (or sometimes two hemispherical ones) is loose in the large hollow seed-cavity.
The rose-apple is indigenous in the East Indies, whence it has been carried to all parts of the tropics. It has become naturalized in the West Indies, in Hawaii, and in other regions. In India, where it is very abundant, it is usually known as gulab-jaman (rose jaman). Yule and Burnell state that the Sanskrit name jambu is applied in the Malay language, with distinguishing adjectives, to several species of Eugenia. Jambo and yambo are sometimes used in English for the rose-apple. In French it is called pomme-rose, in Spanish poma-rosa. Bo-tanically it is sometimes listed as Jambosa vulgaris, DC, sometimes as Caryophyllus Jambos, Stokes.
The tree is hardy in southern California and throughout the southern and central parts of Florida. It succeeds equally well in warm, moist, tropical regions and in the cool and dry sub-tropics. In Florida it is esteemed as an ornamental plant. The fresh fruit is fragrant and attractive, but owing to its peculiar character it is not pleasant to eat unless in small quantities; yet as a preserve or crystallized it is delicious. On account of its beauty it is often used for table decoration. Its enticing perfume, strikingly similar to that of rose-water, makes it unique among fruits.
According to an analysis made in Hawaii by Alice R. Thompson, the ripe fruit contains: Total solids 15.85 per cent, ash 0.29, acids 0.03, protein 0.79, total sugars 11.73, fat 0.18, and fiber 0.98 per cent.
The plant thrives on soils of diverse types. While a rich loam perhaps best suits it, the shallow sandy soils of southeastern Florida have proved altogether satisfactory. It is of slow growth, and comes into bearing when four or five years old. When in bloom it is highly ornamental as it is also when the yellow fruits are ripe. It does not bear heavily, but fruiting extends over a long season.
Propagation of the rose-apple is usually by seed. Like the mango it is peculiar in that its seeds are polyembryonic; thus a single seed may give rise to seven or eight plants. P. J. Wester has found that the species lends itself to bud-propagation. The method is the same as that used with the avocado and mango. Wester says: "Use greenish to brownish and roughish, well-matured budwood; cut the buds an inch and a quarter long. The age of the stock at the point of insertion is unimportant." Large-fruited varieties, or those otherwise desirable, may be propagated by this means.
No named varieties of this very interesting fruit have been disseminated.
Plate XVI. Flowers and fruits of the rose-apple (Eugenia Jambos).