Coconut palm
Family Palmae (or Arecaceae)
Cocos nucifera, coconut palm (C. nucifera 1), is the most widely cultivated of all palms, 20-30 m tall, very common in coastal regions due to their ability to tolerate saline conditions. The palm, like other monocotyledons, has no cambium and therefore secondary thickening does not occur. When the apical meristem has reached its full diameter a trunk can be formed, showing the scars of petioles where leaves have fallen. Borne in a terminal crown the adult palm bears 30-40 pinnate leaves, each leaf up to 6 m long, weighing 10-15 kg. Each year 12-15 leaves are shed and replaced by new ones.
The coconut palm is monoecious with male and female flowers in each spadix, which is borne in the axil of a leaf. The inflorescence, which is 1-2 m long, (C. nucifera 2), (C. nucifera 3) consist of a central axis with tens of lateral branches, bearing a couple of hundred male flowers above, and a few female flowers at the base. The male flowers are pale yellow (C. nucifera 4), (C. nucifera 5), with 6 perianth segments and 6 stamens. The female flowers are bigger, 2-3 cm across, with a large ovary with 3 styles and 6 tepals in 2 whorls (C. nucifera 6). They are receptive after pollen has been shed in order to prevent self-pollination.
The fruit is a drupe, 20-30 cm long and weighing 1-2 kg. The fruit takes 12 months to mature (C. nucifera 7) and consists of the exocarp or outer skin which is tough, smooth and hard, green (C. nucifera 8), yellow, orange (C. nucifera 9) or brown in colour; the mesocarp or fibrous layer which supplies coir (see below); and the endocarp or shell, which is stony, dark brown and bears 3 ‘eyes’ through one of which the embryo will grow. Inside this fruit is a single seed (C. nucifera 10) with a thin brown testa, closely pressed to the endocarp and adhering to the endosperm or ‘ meat’ , which is white and oily. Lying under the soft ‘eye’ is a small embryo, 0.5-1 cm long. In the centre of the seed is a large cavity, partly filled with coconut water. During germination the coconut apple (C. nucifera 11) is formed, a spongy structure which transfers nutrients towards the embryo.
Distribution
The coconut palm is known in Asia and on the Pacific islands for a long time, and it is likely that the palm is of Indo-Pacific origin. Probably the early Spanish explorers discovered the coconut on the Pacific coast of Panama. At the same time it is almost certain that there were no coconuts in the Caribbean or on the Atlantic coast of tropical America at the time of Columbus’ voyages. The palm reached Mexico in 1540. Marco Polo reports the presence of the coconut palm in Sumatra and India in 1280. The palm reached East Africa before the arrival of the first Europeans (C. nucifera 18), probably introduced by the Arabs. The Portuguese took it to West Africa after 1500.
Use
In the tropics the coconut provides a large variety of products: food, drink, oil, fibre (C. nucifera 12), timber, thatch, mats. It plays an important role in the folklore as well. However, economically the coconut is one of the major sources of vegetable oil. It is obtained from the endosperm by drying the white meat into copra (C. nucifera 13), (C. nucifera 14), which is exported to countries which extract the oil themselves. Good copra contains up to 60% of oil. Part of the oil is extracted locally with the help of oxen (C. nucifera 15).
The first important use of coconut oil in the western world was in the manufacture of soap, halfway the 19th century. By the end of the century the margarine industry started to use large quantities of vegetable oils. Later the oil found numerous uses in industry, like in the manufacture of detergents, resins and in cosmetics.
Coconut oil is resistant to rancidity because of the low content of unsaturated acids; thus adding to the keeping quality of baked foods. The residue of copra after expressing the oil is widely used as fodder.
Desiccated coconut is prepared by shredding and drying the meat from which the testa has been removed. It is widely used in bakery products, confectionery and in the oriental cuisine. Coconut milk, produced by squeezing grated meat through a sieve, is used in curries, sweets and drinks. The water in the fresh fruit is drunk as a beverage throughout the tropics. The shells, the stony endocarp of the fruit, are used as fuel in copra kilns (C. nucifera 20). Half shells are used as bowls, cups and scoops. They are also used for buttons, musical instruments and souvenirs.
Coir is obtained from the mesocarp and is used for the manufacture of products like mats, rugs and carpets, ropes and twines, brooms and in upholstery (C. nucifera 16). In Italy it is used for filtering olive oil. Toddy is produced by tapping the unopened flower spathe and having the juice fermented. By distillation of toddy arrack is produced. The terminal bud of the palm, known as palm heart, is eaten cooked or raw. The leaves of the palm are used for thatching, mats, screens, etc., the midribs are made into brooms, baskets etc. The trunk is used for building.
Yields vary greatly with the environmental conditions. The average number of nuts per hectare varies from 2500-7500. The bulk of the crop is owned by smallholders, for whom the coconut palm is an important source of the basic necessities of life, as well as a cash income. It is estimated that world-wide about 4.5 million hectares are under coconut cultivation with over 500 million palms.
The largest producers are the Philippines, Indonesia and India (C. nucifera 17). Other important producing countries are Sri Lanka, Mexico, Malaysia, Papua NewGuinea, and Thailand. The most important importing countries are the US, Germany, Britain, Japan, France and Holland. In 1962 the tonnage of oil entering world trade was surpassed by soy oil.