Breadfruit (Artocarpus altilis) is a rapidly growing tree that is widely planted in the tropics for its edible fruit and value as an ornamental and shade tree. It is of particular economic importance in the Pacific islands, where it is a staple or subsistence crop on many islands. Peterson (2006) argues that the development of vigorous hybrid Breadfruit cultivars led to a "Breadfruit Revolution" 600 to 1200 years ago that was a major driver of sociocultural evolution across Micronesia.
Breadfruit trees are often found in home gardens, in secondary forests, and along roadsides. The spherical to cylindrical rough-skinned fruit is 10 to 30 cm in diameter and 0.25 to 6 kg, with a yellow to green rind and a starchy creamy white to yellow pulp (starch content ~20%). Depending on the variety, seed number may range from none to many. Breadfruit is a "multiple aggregate" fruit (i.e., each fruit is formed from an entire inflorescence consisting of multiple flowers). Seeded fruits have a surface composed of greenish conical spinelike projections, each from a single flower. Seedless fruits have a smoothish surface honeycombed with individual fruits around 5 mm across. The glossy leaves are very large and deeply lobed, dark green and smooth above, lighter and distinctly veined below. I
Breadfruit is monoecious (i.e., individual trees function as both males and females), with separate male and female flower clusters--each consisting of thousands of tiny flowers attached to a spongy core--emerging from leaf bases on the same tree. Breadfruit flowers are cross-pollinated, but pollination is not required for fruit development. The bark of the Breadfruit tree is smooth and brown with warty lenticels; milky juice exudes from the bark when cut (a white milky latex is present in all parts of the tree).
Potted Breadfruit trees (seedless) were brought on the Providence to the West Indies (St. Vincent and Jamaica) from Tahiti in 1793 by Captain William Bligh as a cheap food for slaves on the sugar plantations (an earlier attempt by Bligh on the Bounty was unsuccessful, ending in the famous "Mutiny on the Bounty" in 1789 upon leaving Tahiti). Around the same time, the French brought some Breadfruit trees to several other Caribbean islands.
(Little and Wadsworth 1964; Seddon and Lennox 1980; Ashton 1989; Vaughan and Geissler 1997; Ragone 2006)
The ripe fruits can be eaten raw when ripe, but are more commonly picked when mature (but not quite ripe), then cooked. Seeded varieties are most common in the southwestern Pacific. Seedless varieties are most common in Micronesia and the eastern islands of Polynesia. All the varieties elsewhere in the tropics are seedless. Seeds are dispersed by fruit bats and possibly doves and other birds.
Hundreds of named Breadfruit varieties in the Pacific Islands are propagated vegetatively. Depending on variety, age, and tree condition, fruit yield ranges from fewer than 100 to more than 700 fruits per tree, with an average around 150 to 200. In intensive cultivation, yields of 160 to 500 kg of fruit per tree per year can be achieved. (Ragone 2006)
Some Breadfruit cultivars are fertile diploids (2n = 2x = 56), but many are sterile hybrids or triploids (2n = 3x = 84) and must be vegetatively propagated (Ragone 2001; Zerega et al. 2005 and references therein).
To complement the description but from a cultural perspective, we may add that breadfruit sap was widely used in Polynesia as a caulking material in canoe building. It was mixed with coir to caulk the hulls of wooden canoes. Polynesian linguistic variants to name breadfruit include Mei, Mai, Maiore, 'uru, 'ulu, kuru, guru and gulu.