Many of the mysteries surrounding the coconut palm have still to be solved. One of these mysteries concerns its name. The term cocos came from Portuguese, but in the Sallier papyrus it is revealed that a species of coconut palm existed in Egypt in the XIV century B. C. The name of the fruit, written phonetically, is kuku which means “bark” (since the coconut seed is wrapped in a thick lignified layer). This Coptic word gave rise to the Greek χοχχοσ (coccos) “berry”. The Sanskrit name for the coconut is nari-kera, “succulent fruit”. The Malayan name is nior. The widely divergent names might indicate the regions in which the coconut palm arrived with the natural contribution of the oceans (CHIOVENDA, 1921).
More than 20 billion coconuts are opened every year. Very rarely a pearl is found inside. It is a perfect sphere, about 1cm in diameter, a brilliant creamy white colour, with a flecked surface. The origin of this extraordinary pearl is another mystery. Some maintain that they form, for unknown reasons, only in coconuts which do not have the typical three germination pores. Oriental rulers value these pearls so highly that almost all examples found are today in the Far East. Few Westerners have seen this tropical jewel, since even the most important museums rarely succeed in procuring one (MILNE and MILNE, 1967).
Coconut palms are subject to numerous fungal diseases, bacterial infections, and the most serious virus-like disease, cadang-cadang. Even today little is known about many of these diseases.
It is thought that the purpose of coconut milk is to nourish the immature embryo. The milk has in fact proved to be remarkably valuable in the culture of embryos of other species and in tissue growth in many plants. It is first sterilised in an autoclave and then filtered to remove most of the proteins. The nature of the growth elements in the liquid obtained are not fully known, although we do know that the aminoacids, sugars, alcohol and cytoquinine it contains are important nutritional substances (FOGG, 1977;STREET, 1980).
According to DARWIN (1862), “The most likely hypothesis is that the various species were produced in a single area and they subsequently migrated”. Since the phases of diffusion, the migratory paths, the age and place of origin of the coconut palm cannot be deduced with certainty from its present distribution, its native land is a controversial matter and has been for more than 250 years! Even today, on the threshold of the 3rd millennium, the genetic centre of origin of the palm remains a much debated mystery and, essentially, is unknown. We do not know where this plant originated mainly due to bio-ecological factors and to the influence of man.
BIO-ECOLOGICAL FACTORS – The plant flourishes best on coastlines. It produces floating fruits, extremely resistant to the waves, which are diffused by currents up to 4 500 km from their place of origin. They remain vital in the sea for considerably long periods – around 8 months since the water temperature is low, while on land they germinate after about 90 days –, conserving their germinative capacity.
HUMAN INFLUENCE – It is difficult to determine how humans have contributed to this diffusion. The plant provides sustenance for a number of peoples in the tropics, who have diffused it over vast areas. In 1976, however, PICKERSGILL pointed out that it is still not clear how the coconuts could have already crossed 6 000 miles (around 11,000 km) of Pacific Ocean to reach the western coast of Central America by the time COLUMBUS got there.
CHIOVENDA (1921) believed that the coconut palm was a native of the coral islands of Laccadive and the Maldives (Indian Ocean). In agreement with PURSEGLOVE(1968-72), who indicated the north-west region of Southern America as the centre of origin of the majority of palms related to the coconut, STANDLEY (1968) suggests that the coconut palm has its origins in Central America. More recent scholars are more inclined to believe that it originally came from the East Pacific (Melanesia, Polynesia). The plant would have quickly spread over the Asian continent, arriving somewhat later in the New World by means of the Pacific, and across the Atlantic from Western Africa (PICKERSGILL, 1976).
Few animals are capable of breaking the coconut’s hard husk. In addition to humans, land crabs also feed on them. The Birgus latro LATR., known as the robber crab, is about 40cm long. It takes refuge during the day in a deep burrow in the mud, and comes out at night to nimbly climb up the trunk to the coconuts. It then chips open the fibrous covering with its chelae, makes a hole and feeds on the content.
In 1874, in the novel “L’Île mystérieuse” (“The Mysterious Island”), the French writer J. VERNE describes the explosion of an island caused by the reawakening of a volcano. The water penetrates subsurface fractures in the boiling furnace of magma and is immediately transformed into compressed vapour which causes the island to explode as if it were a boiler without a safety valve. On the morning of August 27th 1883, something similar actually did cause the destruction of the island of Krakatau in the straits between Java and Sumatra in the Southern Pacific. Two months later, when it was possible to approach the site of the apocalyptic explosion, all that remained of the large, flourishing island was a fragment of about 700 m in diameter, completely devoid of all forms of life. 13 years after this tabula rasa caused by the explosion, many coconut palms were in flower on Krakatau. The large and heavy coconuts can only have arrived from the ocean. Krakatau provides us with a natural answer to why the vegetation of the Pacific Islands is so uniform: the sea, far from separating, is in this case a vehicle of union.
When the coconut is ripe, it falls from the tree, rolls across the beach, and is picked up by the waves. On other occasions it falls directly into the sea when the trunk of the palm curves out over the beach. In the water the coconut begins its extraordinary adventure. Impermeable and thermal-insulated, the fruit is carried by the waves and surface currents until the tides and the undertow roll it onto a low-lying beach. Sometimes a storm hurls it onto the shore. After being washed by rain water, the heat of the sun breaks the external husk. The internal fibres, no longer protected, absorb humidity and they dilate, exposing the seed which begins to germinate. This seems to highlight the fact that the biological function of the fruit is to act as a vehicle for the seed.
Morphological characteristics or phenotypical characteristics are the expression of the genotype, of environmental effects and of the interaction between them (HILL et al., 1998). The reproductive organs of the coconut are also capable of adapting themselves to the environment. Crossing the oceans in its hard protective shell, the palm seed demonstrates its enormous capacity to survive and to adapt itself to the sea environment. Although coconuts fall onto the hard coastal sand from as high as 30 m, they do not break, but rather they bounce in their fibrous coating. This protects the rigid yet fragile shell which could break and thus destroy the embryo when the fruits are hurled against rocks by the waves. The fibrous layer also contains air which permits the fruit to float on the sea. It can travel across the ocean for miles before being flung by the tides onto another coastline with conditions which will allow it to germinate. It is also true that countless fruits are lost when transported to polar areas (the Gulf Stream has transported coconuts from the coasts of Northern and Southern America to Norway: KLEIN, 1976), where the coconut palm has no possibility of survival.
The fruits float perfectly thanks to both their very thick and light pericarp which protects the seed from the salt water (which means certain death for a land plant) and to their internal cavity. The interior contains all they need for a long journey: an abundant supply of nutritive substances and around 250 ml of water. The albumen nourishes the young plant for a number of months, reaching a height of 30 cm, until it can put down roots. Coconuts are like “small space ships”: vehicles capable of carrying out a long journey and, at the same time, ensuring the survival of the “crew” – the embryo – even in a completely alien environment. The germinative pore is on one of the three faces of the fruit which, due to its centre of gravity position, always remains out of the water when afloat. This is another reason why the seeds can resist so long in water. Moreover, larger fruits are more easily transported.