Jambosa malaccensis (L.) DC.

Tree, 5-20 m tall, with straight trunk, 20-45 cm diameter, often branched near the base and with broadly ovoid canopy. Leaves opposite, elliptic-oblong, 15-38 cm x 7-20 cm, thick-coriaceous, petiole 0.5-1.5 cm long, thick, red when young. Inflorescences exclusively on defoliate twig-parts, short and dense, 1-12- flowered; flowers 5-7 cm in diameter, red; calyx-tube ventricose towards apex, 1.5-2 cm long, with broad lobes 4-8 mm long; petals 4, oblong-ovate or orbicular-ovate, up to 2 cm long, dark red; stamens numerous, up to 3.5 cm long, with red filaments; style 3-4.5 cm long, red. Fruit a berry, ellipsoid, 5-8 cm in diameter, crowned by the incurved non-fleshy calyx segments, dark red or purplish-yellow or yellow-white; flesh 0.5-2.5 cm thick, juicy, white, fragrant. Seed 1 per fruit, globose, 2.5-3.5 cm in diameter, brown.

There are definite flowering seasons, often two, sometimes three in a year, but the timing varies from year to year. There seems to be no regular growth rhythm for Malay apple. Apparently the trees are triggered into bloom (by wet weather following a dry period) more readily than water apple (S. aqueum) and wax jambu (S. samarangense) trees; at any rate, Malay apple usually has the most crops per year. Malay apples ripen about 60 days after bloom.

The trees prefer heavy soils and easy access to water instead of having to search for water in light deep soils.

The trees are at home in fairly moist tropical lowlands up to 1200 m elevation. Malay apple is restricted to the wetter climates. The species require a reliable water supply and are often planted along streams or ponds.

The trees of S. malaccense are cultivated in home gardens, often planted along driveways and paths.

Propagation from seed is common. Seeds are sometimes abortive. Seeds lose their viability quickly and should be sown fresh from the fruit. Clonal propagation through air layers, cuttings or budding is not difficult. Air layering is commonly employed in South-East Asia. The modified Forkert method is recommended for budding. Seedlings of the same or other Syzygium species are used as rootstocks. In Java 'jambu klampok' or 'kopo' (S. pycnanthum Merr. & Perry, syn. Eugenia densiflora (Blume) Duthie) is recommended as rootstock because it is hardy and not attacked by termites.

Tree spacing ranges from 6-8 m. The trees receive little attention after the first year or two when manuring, weeding, mulching and watering ensure rapid increase of tree volume. Trees which bear well benefit from compound fertilizers applied after harvest and supplemented with a top dressing as soon as the inflorescences are being formed. There appears to be no experience with pruning or fruit thinning.

There are no specific recommendations for crop protection, but the incidence of pests and diseases certainly warrants a study of the causal organisms and their control.

Food: The tree is grown for their fruit, which substitute for one another in the marketplace. Whereas S. malaccense can easily be recognized, it is not easy to distinguish between the various S. aqueum and S. samarangense fruits. The ripe fruit is sweet and is mainly eaten fresh. Malay apples are often stewed with other fruit to tone down the sour taste of the latter. Medicine: Various parts of the tree are used in traditional medicine, and some have in fact been shown to possess antibiotic activity. In particular the bark, leaves and roots of Malay apple are used against different ailments in a number of countries, also outside Asia (e.g. Hawaii, Brazil). Timber: The wood is reddish, hard and grows to dimensions large enough for construction purposes.