It may be tempting to call oranges, papayas and bananas tropical fruits that grow on trees, but they don't fit the category. Oranges are subtropical in origin, best in seasonally warm, wet to cool, dry climates, and both papayas and bananas grow on large tree-like herbs; these trunked plants lack bark or cambium and thus cannot be considered a tree. Tropical fruits are better categorized as those that grow in the lowland, humid, warm regions nearest the equator. Day length around the year is nearly constant, and only wet and dry seasons occur, not winter, spring, summer and fall.
Captain William Bligh of the HMS Bounty carried breadfruit on board, actually introducing this tropical fruit tree into the West Indies from Tahiti. Breadfruit (Artocarpus altilis) is originally native to Indonesia and Malaysia, according to Margaret Barwick, author of "Tropical and Subtropical Trees." Growing 65 feet tall and 70 feet wide, the breadfruit tree blooms twice per year. The tiny flowers are inconspicuous, but the female blossoms become football-sized green fruits that dangle from a thick stem on tree branches. Rich in carbohydrates and vitamins A and C, breadfruit has spiny/warty light green skin and a dense, potato-like flesh in the middle. The leaves of this tree are large, deeply lobed and attractively glossy green.
Closely related to the breadfruit is the jackfruit tree (Artocarpus heterophyllus), a native of India. Growing 70 feet tall with large, nonlobed leaves that cast excellent shade, the jackfruit arguably produces the world's largest fruits, as they measure from 12 to 24 inches in diameter and weigh up to 40 lbs. each, according to Robert Riffle in his book, "The Tropical Look." These fruits are oval and light green with warty skin and hang directly off the trunk or large branches. Cut open a jackruit, and you'll see segments called "pegs," which contain a white edible seed and pectin-rich fibers called "rags." Carbohydrates, calcium and phosphorus are the nutritious aspect of the fruits, which when ripe taste and smell strongly sweet.
Perhaps better known as "starfruit," carambola (Averrhoa carambola) trees grow about 30 feet tall and equally wide, with irregular floppy branches. Native to Malaysia eastward into Melanesia, carambola bears pretty pink-red tiny flowers that are insect-pollinated. Flowering occurs in several flushes across the year. The five-grooved fruits dangle from the branches and look like translucent lanterns with a waxy skin. When ripe, they are yellow, sweet and juicy, having a flavor like a combination of mango, pineapple and pear. They are rich in vitamin C.
The fruits of the rambutan (Nephelium lappaceum) are exotic and pretty. Officially known as a drupe, the golf ball-sized fruits are red with long, soft, curling spines--making them look like tiny sea urchins. The tree has glossy bright-green leaves with whitish undersides. It matures to a height of 85 feet tall and nearly 100 feet wide. Native to western Malaysia, the taste and quality of the rambutan fruits vary considerably, according to Margaret Barwick. The skin cracks away to reveal a slimy, beige flesh around the central seed; it resembles a litchi. The best fruits are juicy, with a pleasant, mild and sub-acid taste.
Native from India to Malaysia, the mango (Mangifera indica) tree is pretty when its newest leaves emerge. They are coppery pink and line the branches in spring and summer. A stalked flower inflorescence appears from branch tips in spring, too. The tiny blossoms are fragrant and later develop into dangling, globe-shaped fruits. When ripe, the mango fruit is oblong and has an aromatic flesh and skin that is blushed red, yellow, pink and green. Mango skin has a milky sap that can cause rashes, but the yellow to gold sweet, fibrous flesh is deliciously sweet and slimy. Mango trees can grow up to 100 feet tall and 80 feet wide when very old.