The most common type of coconut palm is the type belonging to the Arecaceae (Palmae) family called the Cocos nucifera. Botanic description Cocos nucifera trees have a smooth, columnar, light grey-brown trunk, with a mean diameter of 30-40 cm at breast height, and topped with a terminal crown of leaves. Tall selections may attain a height of 24-30 m; dwarf selections also exist. Trunk slender and slightly swollen at the base, usually erect but may be leaning or curved. Leaves pinnate, feather shaped, 4-7m long and 1-1.5 m wide at the broadest part. Leaf stalks 1-2 cm in length and thornless. Inflorescence consists of female and male axillary flowers. Flowers small, light yellow, in clusters that emerge from canoe-shaped sheaths among the leaves. Male flowers small and more numerous. Female flowers fewer and occasionally completely absent; larger, spherical structures, about 25 mm in diameter. Fruit roughly ovoid, up to 5 cm long and 3 cm wide, composed of a thick, fibrous husk surrounding a somewhat spherical nut with a hard, brittle, hairy shell. The nut is 2-2.5 cm in diameter and 3-4 cm long. Three sunken holes of softer tissue, called ‘eyes’, are at one end of the nut. Inside the shell is a thin, white, fleshy layer known as the ‘meat’. The interior of the nut is hollow but partially filled with a watery liquid called ‘coconut milk’. The meat is soft and jellylike when immature but becomes firm with maturity. Coconut milk is abundant in unripe fruit but is gradually absorbed as ripening proceeds. The fruits are green at first, turning brownish as they mature; yellow varieties go from yellow to brown. The generic name seems to be derived from the Portuguese ‘coco’, meaning ‘monkey’. History of cultivation Origin of C. nucifera is disputed but evidence favours Southeast Asia, with subsequent migration east and west, to the Pacific and Latin America, and to India, Madagascar and East Africa. Coconuts did not reach West Africa until they were taken there by the Portuguese, around the Cape of Good Hope, after AD 1500. Natural Habitat C. nucifera is unknown in the wild state. In the coastal areas of the tropics and subtropics where it is grown, it requires a hot, moist climate and deep alluvial or loamy soil, thriving especially near the seaboard, but also considerable distance inland, provided climatic conditions and soil are suitable. Rocky, laterite or stagnant soils are unsuitable. Geographic distribution Native : Brunei, Cambodia, Indonesia, Laos, Malaysia, Myanmar, Philippines, Singapore, Thailand, Vietnam Exotic : Argentina, Benin, Bolivia, Brazil, Burkina Faso, Cameroon, Chad, Chile, China, Colombia, Cook Islands, Cote d'Ivoire, Ecuador, Fiji, French Guiana, Gambia, Ghana, Guinea, Guyana, Haiti, India, Jamaica, Kenya, Kiribati, Liberia, Madagascar, Mali, Marshall Islands, Mauritania, New Caledonia, Niger, Nigeria, Papua New Guinea, Paraguay, Peru, Samoa, Senegal, Sierra Leone, Solomon Islands, Sri Lanka, Surinam, Togo, Tonga, Uganda, United States of America, Uruguay, Vanuatu, Venezuela, Zanzibar Biophysical limits Altitude: 520-900 m, Mean annual temperature: 20-28 deg. C, Mean annual rainfall: 1000-1500 mm Soil type: C. nucifera is tolerant to soil variations but its natural preference is for sandy, well-aerated and well-drained soils. It has considerable ability to adapt to soils of heavier texture. Reproductive Biology The tall varieties reproduce by cross-pollination. Male flowers open first, producing pollen for about 2 weeks. Female flowers are not usually receptive until about 3 weeks after the opening of the inflorescence, making cross-pollination the usual pattern. Wind is the main pollinating agent. Reproduction in dwarf varieties is generally through self -pollination. Female flowers are receptive about a week after the male flowers open, both ending at about the same time. C. nucifera flowers approximately after the 6th year. Propagation methods Seed has no dormancy, and growth of embryo and seedling is continuous. Germination may begin while the fruits are still attached to the palm, as can happen in the Malayan Dwarf and San Blas. Tissue culture is a popular method of vegetative propagation for producing a large number of progeny. For seed propagation, nuts are collected from selected mother palms or special seed gardens. Products Food: Copra, the dried coconut endosperm, contains an edible cooking oil (coconut oil). The apical region of C. nucifera (‘millionaire salad’) is a food delicacy in areas where it is grown. Other food derivatives of coconut include coconut chips, coconut jam, coconut honey, coconut candy and other desserts. Fodder: Copra meal and coconut cake, the residues of oil extraction from copra containing approximately 20% protein, 45% carbohydrate, 11% fibre, fat, minerals and moisture, are used in cattle feed rations. Apiculture: C. nucifera is an important pollen source for honey production. Where sap is tapped from unopened inflorescences for toddy-making, many bees drain in the collecting pots. The honey may be greenish-yellow like the motor oil and crystal clear if monofloral. Granulation is medium (takes up to 3 months). Fuel: The high moisture content of C. nucifera wood and the difficulty of splitting it has made it relatively unpopular as firewood. Coconut shell charcoal is a major source of domestic fuel in the Philippines. It is also exported to Japan and the USA. Coconut oil can be used as a substitute for diesel oils, for electric generating plants and motor vehicles. However, this use is non-economic in most situations at the present prices of fuel oil. Fibre: Three types of fibres are obtained from the coconut husks: mat fibre or yarn fibre, used in making mats; bristle fibre, used for brush making; and mattress fibre, used in stuffing mattresses and in upholstery. Leaflets are used in braiding mats, baskets and hats. Timber: C. nucifera timber has traditionally been used in tropical countries for the structural framework of houses. Coconut timber taken from the lower and middle parts of the trunk can be used for load-bearing structures in buildings, such as frames, floors and trusses. Coconut trunks can be used for poles, as they have great strength and flexibility. The wood can also be used for furniture and parquet flooring. Lipids: The oil contains fatty alcohol and glycerine used in soaps, detergents, shampoos cosmetics, pharmaceuticals and explosives. Alcohol: Sap from the tender, unopened inflorescence (coconut palm sap) is used in the producing areas for toddy, or tuba, a beverage obtained by natural fermentation. Tuba contains 6-7.5% alcohol. The distillation of fermented coconut toddy yields a spirit called arrack, produced commercially in Sri Lanka and the Philippines. Other products: Coconut-shell flour, obtained from grinding clean, mature coconut shells to fine powder, is used as a filler in thermoplastic industry and an abrasive for cleaning machinery. Coconut-shell charcoal may be processed further into activated carbon that has many industrial applications, including general water purification, crystalline sugar preparation and gold purification. The edible mushrooms of the genus Auricularis grow well on coconut stems and are readily sold in China and elsewhere.