Inocarpus fagifer
Encyclopedia
Inocarpus fagifer, commonly known as the Tahitian Chestnut, Polynesian Chestnut, Aila or Mape tree, is a species of flowering plant
Flowering plant
The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...
in the subfamily Faboideae
Faboideae
Faboideae is a subfamily of the flowering plant family Fabaceae or Leguminosae. One acceptable alternative name for the subfamily is Papilionoideae....
of the legume family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
, Fabaceae
Fabaceae
The Fabaceae or Leguminosae, commonly known as the legume, pea, or bean family, is a large and economically important family of flowering plants. The group is the third largest land plant family, behind only the Orchidaceae and Asteraceae, with 730 genera and over 19,400 species...
. The tree has a wide range in the tropics of the south-west Pacific and south-east Asian regions, and a history of traditional use by the peoples of Polynesia
Polynesia
Polynesia is a subregion of Oceania, made up of over 1,000 islands scattered over the central and southern Pacific Ocean. The indigenous people who inhabit the islands of Polynesia are termed Polynesians and they share many similar traits including language, culture and beliefs...
and Melanesia
Melanesia
Melanesia is a subregion of Oceania extending from the western end of the Pacific Ocean to the Arafura Sea, and eastward to Fiji. The region comprises most of the islands immediately north and northeast of Australia...
. It is the only edible and culturally important member of the genus Inocarpus
Inocarpus
Inocarpus is a small genus of flowering plants belonging to the subfamily Faboideae of the legume family, Fabaceae. It has three species distributed in Malesia.-Species:* Inocarpus fagifer Fosberg - Tahitian Chestnut...
.
Description
There is great diversity in the size, form, shape and colour of the Tahitian Chestnut, and of its leaves, flowers and fruits. Because of its long history of cultivation and its tendency to become naturalised where introduced, it is likely that, over its wide range, the species contains several originally farmer-selected cultivarCultivar
A cultivar'Cultivar has two meanings as explained under Formal definition. When used in reference to a taxon, the word does not apply to an individual plant but to all those plants sharing the unique characteristics that define the cultivar. is a plant or group of plants selected for desirable...
s that have not been recognised or described.
Size, form and lifespan
The Tahitian Chestnut is a medium-sized, evergreen tropical tree. It may grow to 30 m in height, though 20 m is more usual, with a crown diameter of 4–6 m. Mature tree trunks have a typical diameter at breast heightDiameter at breast height
Diameter at breast height, or DBH, is a standard method of expressing the diameter of the trunk or bole of a standing tree. DBH is one of the most common dendrometric measurements....
of 300 mm, although some grow to a diameter of 900 mm. The trunks are distinctively buttressed at the base and fluted. The branches are arranged spirally, with secondary branching forming a dense network within the canopy. The bark is rough, flaky and brown, becoming greyer with age. From the buttresses a dense network of lateral roots extends through the topsoil around the tree, which has only a shallow taproot
Taproot
A taproot is an enlarged, somewhat straight to tapering plant root that grows vertically downward. It forms a center from which other roots sprout laterally.Plants with taproots are difficult to transplant...
. It has a lifespan of 80–90 years.
Leaves
The dark green leaves are simple, oblong, alternate, and leathery. They are 160–390 mm long and 70–130 mm wide. The petiolePetiole (botany)
In botany, the petiole is the stalk attaching the leaf blade to the stem. The petiole usually has the same internal structure as the stem. Outgrowths appearing on each side of the petiole are called stipules. Leaves lacking a petiole are called sessile, or clasping when they partly surround the...
is 5 mm long. The apex is pointed and the base lobed, with an entire margin. The veins are opposite and yellow.
Flowers
The fragrant flowers cluster along a short rachisRachis
Rachis is a biological term for a main axis or "shaft".-In zoology:In vertebrates a rachis can refer to the series of articulated vertebrae, which encase the spinal cord. In this case the rachis usually form the supporting axis of the body and is then called the spine or vertebral column...
at the ends of the branches and twigs. About 10 mm long, they have five white to cream or pale yellow petals. Trees begin flowering at 3–5 years old, with the flowering season usually taking place in November–December, and fruiting in the following January–February, though this varies through the tree’s range and from year to year.
Fruit
The tree starts bearing fruit at about eight years old. The fruits are slightly flattened, irregularly ovoid, rounded or oblong, and flanged at one end. Produced singly or in clusters, they weigh 50–110 g and are 46–130 mm long, 34–120 mm wide, and 40 mm thick. The smooth skin covers a fibrous shell which holds the kernel. As the fruits ripen their colour changes from green to yellow or orange-brown. The mature fruits are usually indehiscentDehiscence (botany)
Dehiscence is the opening, at maturity, in a pre-defined way, of a plant structure, such as a fruit, anther, or sporangium, to release its contents. Sometimes this involves the complete detachment of a part. Structures that open in this way are said to be dehiscent...
.
The seed is white and kidney-shaped and is contained within the thin brown, fibrous shell. It is relatively large, weighing 5–50 g, 20–70 mm long by 16–40 mm wide. The seed is toxic when raw but edible when cooked. It is perishable, with a short shelf life
Shelf life
Shelf life is the length of time that food, drink, medicine, chemicals, and many other perishable items are given before they are considered unsuitable for sale, use, or consumption...
. The fleshy mesocarp, or pulp, of the fruit is eaten by cockatoo
Cockatoo
A cockatoo is any of the 21 species belonging to the bird family Cacatuidae. Along with the Psittacidae and the Strigopidae , they make up the parrot order Psittaciformes . Placement of the cockatoos as a separate family is fairly undisputed, although many aspects of the other living lineages of...
s and flying foxes
Pteropus
Bats of the genus Pteropus, belonging to the megabat or Megachiroptera sub-order, are the largest bats in the world. They are commonly known as the fruit bats or flying foxes among other colloquial names...
which act as seed dispersal
Seed dispersal
Seed dispersal is the movement or transport of seeds away from the parent plant. Plants have limited mobility and consequently rely upon a variety of dispersal vectors to transport their propagules, including both abiotic and biotic vectors. Seeds can be dispersed away from the parent plant...
agents.
Distribution and habitat
The Tahitian Chestnut grows in the humid lowland tropicsTropics
The tropics is a region of the Earth surrounding the Equator. It is limited in latitude by the Tropic of Cancer in the northern hemisphere at approximately N and the Tropic of Capricorn in the southern hemisphere at S; these latitudes correspond to the axial tilt of the Earth...
with a moderate to high, uniformly distributed or mainly summer rainfall of 1500–4300 mm annually, at altitudes ranging from sea level to 500 m. It grows in a wide range of soil
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...
s, including those that are highly calcareous and saline, poorly drained to waterlogged, or those with medium to very low fertility, as well as in mildly acidic to very alkaline coastal soils.
The tree was evidently cultivated more intensively in the past, as it has become extensively naturalised
Naturalisation (biology)
In biology, naturalisation is any process by which a non-native organism spreads into the wild and its reproduction is sufficient to maintain its population. Such populations are said to be naturalised....
, and is now found mainly in the wild. Its distribution spreads from Malaysia in the west across Melanesia
Melanesia
Melanesia is a subregion of Oceania extending from the western end of the Pacific Ocean to the Arafura Sea, and eastward to Fiji. The region comprises most of the islands immediately north and northeast of Australia...
, north-eastern Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
and Micronesia
Micronesia
Micronesia is a subregion of Oceania, comprising thousands of small islands in the western Pacific Ocean. It is distinct from Melanesia to the south, and Polynesia to the east. The Philippines lie to the west, and Indonesia to the southwest....
, to the Marquesas of Polynesia
Polynesia
Polynesia is a subregion of Oceania, made up of over 1,000 islands scattered over the central and southern Pacific Ocean. The indigenous people who inhabit the islands of Polynesia are termed Polynesians and they share many similar traits including language, culture and beliefs...
in the east. It is commonly found in secondary forest
Secondary forest
A secondary forest is a forest or woodland area which has re-grown after a major disturbance such as fire, insect infestation, timber harvest or windthrow, until a long enough period has passed so that the effects of the disturbance are no longer evident...
, along the edges of old gardens, riverbanks, in swamps, coastal areas, coconut
Coconut
The coconut palm, Cocos nucifera, is a member of the family Arecaceae . It is the only accepted species in the genus Cocos. The term coconut can refer to the entire coconut palm, the seed, or the fruit, which is not a botanical nut. The spelling cocoanut is an old-fashioned form of the word...
plantation
Plantation
A plantation is a long artificially established forest, farm or estate, where crops are grown for sale, often in distant markets rather than for local on-site consumption...
s and mangrove
Mangrove
Mangroves are various kinds of trees up to medium height and shrubs that grow in saline coastal sediment habitats in the tropics and subtropics – mainly between latitudes N and S...
s.
Uses
The tree has a wide variety of traditional uses, exploiting almost every part of the plant. The leaves and bark have found medicinalTraditional medicine
Traditional medicine comprises unscientific knowledge systems that developed over generations within various societies before the era of modern medicine...
uses, fallen branches serve as firewood
Firewood
Firewood is any wood-like material that is gathered and used for fuel. Generally, firewood is not highly processed and is in some sort of recognizable log or branch form....
, green wood is burned to dry copra
Copra
Copra is the dried meat, or kernel, of the coconut. Coconut oil extracted from it has made copra an important agricultural commodity for many coconut-producing countries. It also yields coconut cake which is mainly used as feed for livestock.-Production:...
, and the timber
Timber
Timber may refer to:* Timber, a term common in the United Kingdom and Australia for wood materials * Timber, Oregon, an unincorporated community in the U.S...
is used for crafts such as carvings and tool handles, as well as for building canoes and for general light construction.
The fleshy mesocarp is inedible for humans, but the seed kernels serve as an important indigenous food in many island countries in the Pacific. The kernel has a protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
content of about 5% and carbohydrate
Carbohydrate
A carbohydrate is an organic compound with the empirical formula ; that is, consists only of carbon, hydrogen, and oxygen, with a hydrogen:oxygen atom ratio of 2:1 . However, there are exceptions to this. One common example would be deoxyribose, a component of DNA, which has the empirical...
content of 22%, and needs to be cooked to make it edible. Methods of preparation include roasting, grilling, boiling and baking. In Papua New Guinea
Papua New Guinea
Papua New Guinea , officially the Independent State of Papua New Guinea, is a country in Oceania, occupying the eastern half of the island of New Guinea and numerous offshore islands...
, the Solomon Islands
Solomon Islands
Solomon Islands is a sovereign state in Oceania, east of Papua New Guinea, consisting of nearly one thousand islands. It covers a land mass of . The capital, Honiara, is located on the island of Guadalcanal...
, Vanuatu
Vanuatu
Vanuatu , officially the Republic of Vanuatu , is an island nation located in the South Pacific Ocean. The archipelago, which is of volcanic origin, is some east of northern Australia, northeast of New Caledonia, west of Fiji, and southeast of the Solomon Islands, near New Guinea.Vanuatu was...
, Fiji
Fiji
Fiji , officially the Republic of Fiji , is an island nation in Melanesia in the South Pacific Ocean about northeast of New Zealand's North Island...
and in Polynesia the cooked kernels are often mashed into a pudding
Pudding
Pudding most often refers to a dessert, but it can also be a savory dish.In the United States, pudding characteristically denotes a sweet milk-based dessert similar in consistency to egg-based custards, though it may also refer to other types such as bread and rice pudding.In the United Kingdom and...
.
The tree has uses in agroforestry
Agroforestry
Agroforestry is an integrated approach of using the interactive benefits from combining trees and shrubs with crops and/or livestock.It combines agricultural and forestry technologies to create more diverse, productive, profitable, healthy and sustainable land-use systems.-Definitions:According to...
in coastal and soil stabilisation, as an overstorey for crops needing shade, such as cocoa, and as a windbreak
Windbreak
A windbreak or shelterbelt is a plantation usually made up of one or more rows of trees or shrubs planted in such a manner as to provide shelter from the wind and to protect soil from erosion. They are commonly planted around the edges of fields on farms. If designed properly, windbreaks around a...
. The main products are the edible kernels and the timber. Trees over 25 years old can produce up to 75 kg of fruit a year.
Mythology
Examples of local folklore about the tree:- It was believed in Samoa that humans originated from the Tahitian Chestnut tree.
- In Vanuatu the first woman was a man who had been emasculatedEmasculationEmasculation is the removal of the genitalia of a male, notably the penis and/or the testicles.By extension, the word has also come to mean to render a male less of a man, or to make a male feel less of a man by humiliation. This metaphorical usage of the word is much more common than the...
by having the hot leaves applied to his genitals. - On Choiseul IslandChoiseul IslandChoiseul Island, native name Lauru, is the largest island of the Choiseul Province, Solomon Islands, at .-Description:This island is named after Étienne François, duc de Choiseul....
in the SolomonsSolomon IslandsSolomon Islands is a sovereign state in Oceania, east of Papua New Guinea, consisting of nearly one thousand islands. It covers a land mass of . The capital, Honiara, is located on the island of Guadalcanal...
, a man who betrayed a tribal chief was suffocated by the flatulenceFlatulenceFlatulence is the expulsion through the rectum of a mixture of gases that are byproducts of the digestion process of mammals and other animals. The medical term for the mixture of gases is flatus, informally known as a fart, or simply gas...
produced as a result of the people around him eating the cooked kernels.