Mangifera caesia Jack

Large tree, often attaining majestic proportions, 30(- 45) m tall, and bole 50-80(-120) cm or more in diameter; bole columnar, without buttresses, crown dome-shaped with massive branches; bark greyish-brown, superficially fissured, containing irritant sap. Leaves elliptic to lanceolate, more or less obovate, (7-)10-12(-30) cm x (3-)4-5.5(-10) cm, medium green and shiny above, paler below, often crowded at the end of stout branchlets, coriaceous, blunt or bluntly acuminate; midrib thick, flattened, raised above, base gradually decurrent; petiole stout, flattened, 1-1.5(-2.5) cm long. Panicle terminal, 15-25(-40) cm long, much branched with stout rachis and branches, densely flowered, pale pink; flowers 5-merous, pale lilac, fragrant; petals linear, up to 10 mm long, not strongly reflexed as in most other mango flowers, only slightly reflexed in the upper part; fertile stamen 1, filament 5 mm long, white at base, purple towards the apex, 4 teeth-like staminodes; disc narrow, stipe-like, 1-1.5 mm long, pale green; ovary obliquely globose, reddish brown, style excentric, 8 mm long, white, becoming violet after anthesis. Fruit an obovate-oblong drupe, necked at base, 12-15(-20) cm x 6-7(-12) cm; skin yellowish or pale brownish, very thin (1 mm); pulp whitish, soft and juicy, fibrous, with a peculiar sourish taste and strong smell at maturity. The 'wani' form: fruit ellipsoid, rounded, 9-11 cm x 6.5-7 cm, glossy pale green at maturity, flesh milky white; the best forms are almost fibreless with a sweet pleasant taste; stone ellipsoid-lanceolate, ca. 7 cm x 3.5-4 cm, not flattened, thin-walled, endocarp not woody, made of matted coarse fibres, monoembryonic. Wild forms have sour fruits but there is a cultivar in Borneo and Bali with sweet, fibreless and tasty fruits. The smell of the fruit pulp is rather offensive, and the white juice of the immature fruit is very irritating to the skin and when ingested. M. caesia closely resembles M. kemanga Blume, but differs in the longer petiole and the yellowish or whitish-green and smooth fruit.

The trees bloom profusely and old trees can produce thousands of fruits. The fruit ripens 3 months after anthesis. The fruits come to maturity during the rainy season, from November to March in eastern Kalimantan; flowering is between October and December. Trees in Sabah flower between February and April, the fruit ripens from August to October. M. caesia is deciduous, standing bare for some time before shedding the very large bud scales that envelop new twigs and inflorescences.

M. caesia are restricted to the wet tropical lowlands, generally below 400 m (rarely up to 800 m). It require a rainfall which is evenly distributed through the year. It also stand inundation well and are commonly cultivated on periodically inundated riverbanks in East Kalimantan. It is rather rare in forests and found more frequently in periodically inundated areas and marshes.

In cultivation binjai has spread to Bali, Peninsular Thailand and, rarely, to western Java.

It is propagated from seed, an indication that the agronomy of the crops has received little attention. Presumably grafting on seedling stock would be possible, in particular through inarching potted, decapitated rootstocks into twigs of mother trees. Grafting on Mangifera indica L. has been attempted without success, probably because this species is not closely related.

Mature trees require much space, 12-16 m each way. No particulars about husbandry or yield levels have been published.

No particulars about pests and diseases have been published.

Food: The juicy, sweetish-sour binjai fruit can be eaten fresh when ripe. The 'wani' form, which is mainly found in Bali but also in East Kalimantan, is much liked this way and fetches a high price in local markets, as the fruit is palatable, juicy and sweet, almost fibreless, the foetid rank smell being completely absent. It is excellent for making creamy juices. Binjai is often used to prepare a spice based on chillies ('sambal') which is eaten with river fish. In some areas the flesh of ripe fruit is pickled and preserved with salt in jars, to be able to make this sambal when there is no fresh fruit. Timber: The wood is used for light construction.