Jambu Syzygium malaccense, S. aqueum, Eugenia javanicum, E. uniflorum
Many fruits share the name of jambu and also share a thirst-quenching juiciness. While they may be related, the varieties look quite different and taste different too. The one with the most flavour is the large (about the size of a small apple), oval, white variety which develops a pink blush on one side when ripe. The flesh is pure white and slightly sweet. Also known as Malay apple.
A more common bright red variety is known as wax jambu or water roseapple. These very attractive fruits range from white faintly streaked with pink to an overall deep pinkish-red colour that one sees on jelly beans. The thin skin is so shiny that it is obvious why it is called wax jambu. It is pear shaped, small - about 2-3 cm (3/4-1 in) long and 4-5 cm (11/2-2 in) across - and with a prominent, fleshy calyx on the broad end. As a contrast to its attractive colour, the slightly acid flavour is a big disappointment. Children are attracted to them for their colour and shine, but most people dont bother eating them except that they are a good thirst-quencher. Even for jam making, were it not for a copious dose of lime juice they would not convey much flavour at all. In Thailand, the young leaves of Eugenia cymosa are used raw with spicy dips.
Medicinal uses: In Malaysia the dried, powdered leaves are used for treating a cracked tongue, the roots to relieve itch. In Indonesia the bark is made into a mouthwash to treat thrush. In Indochina the seeds and fruits are used to make a cooling drink, administered for fevers.
Other Languages: Malaysia: jambu ayer, jambu bol Sri Lanka: pini jambu Thailand: daeng khlong