Syzygium samarangense aka Java Apple

Syzygium samarangense is an evergreen fruit tree in the Myrtaceae family. Its common names include Java apple, wax apple, and wax jambu. Its native range stretches from northeast India to northern Vanuatu. It grows in wet tropical regions, including coastal woods. It also grows in scrub behind beaches. People grow it in tropical home gardens for its fruit.

The tree grows fast and forms a broad, uneven crown. Its branches leave gaps rather than forming a dense canopy. One reference gives a height of about 39 feet [12 metres]. The wider reported range is 16–49 feet [5–15 metres]. Its short trunk bends and branches close to the ground. The trunk can reach 0.8–1.6 feet [0.25–0.5 metres] across. It keeps its leaves through the year and can provide shelter.

Bees pollinate the flowers, which also have traditional medicinal uses. The pear-shaped fruit has a waxy skin and spongy flesh. Its texture ranges from fairly dry to crisp and juicy. The taste is mild, with a slight sour edge. Fruits measure about 0.13–0.20 feet [0.04–0.06 metres] long. Cultivated trees can bear larger fruit. People eat ripe fruit raw and cook green fruit into sauce. Pink fruit tends to have more juice and better flavour. Local markets sell the fruit, and some reaches markets abroad.

This tree needs warmth and a steady supply of water. It grows best with daytime temperatures of 23–28°C. Temperatures at or below 0°C can kill it. Full sun suits it best, though it accepts light shade. It grows in several soil types and prefers good drainage. Drought does not suit it, despite its preference for a long dry season. Growers plant it near ponds or streams for reliable moisture. Fresh seed needs prompt sowing because it loses viability quickly. Young seedlings need shade; air layering offers another means of propagation.

The hard, reddish wood has uses in building huts. The flowers contain tannins and have shown weak antimicrobial effects in tests. Traditional uses include treating fever and diarrhoea, but these are not treatment recommendations. The source lists no known hazards. That statement does not establish safety for every plant part or for pets.