Plant

Plant

  • FAMILY – Palmae JUSS. (Palmaceae) or Arecaceae. Over 2 800 species are grouped in 200 genera.
  • GENUS – In the last century it was believed that the Cocos L. genus included more than 60 different species. In very old gardens, for example, it is still possible to find examples of Arecastrum romanzoffianum BECC. defined Cocos romanzoffiana CHAM. Today Cocos is considered to be a monotypic genus.
  • SCIENTIFIC NAME – Latin: Cocos nucifera L.
  • POPULAR NAMES – English: Coconut palm – Coconut tree. French: Cocotier nucifère – Cocotier porte-noix. Spanish: Cocotero. German: Kokosnuß. Italian: Palma da cocco – Noce di cocco.
  • ETYMOLOGY – Cocos comes from the Portuguese macaco = “monkey”. The three germination pores at the basal tip of the endocarp, one open and two closed, are similar to the mouth and eyes of a monkey; nucifera comes from the Latin nux-nucis and fero = “which produces nuts”.
  • CHROMOSOME NUMBER – 2n = 16.
  • CULTIVAR – Countless varieties exist as the individual plants are derived from continuous cross-pollination, vegetative propagation being impossible. We can identify groups with common characteristics but, in practice, each plant is different to the others. “Dwarf Golden Malay”: to 8 m; small fruit numerous yellow, green or red. “Dwarf Green”: green fruit, with improved resistance to coconut yellows. “Dwarf Samoan”: short trunk stout; large fruit rounded, green or red husk. “Nina”: habit compact, graceful leaves, long, narrow, shiny, green.

DESCRIPTION

TREE – Large unbranched palm, with slim, columnar trunk, 30 m in height, 30 cm in diameter, slightly thicker at the base. Like all palms, it has no cambium, and therefore no mechanism for cicatrising wounds. Therefore, the footholds incised in the trunk by gatherers in order to reach the coconuts remain on the palm. There are no annual growth rings, but as the adult palm loses 12-14 leaves per year, the age of the plant can be calculated by counting the number of leaf scars. Since there is no continuous phloem ring, coconut palms do not die if their trunks are incised.

ROOTS – Basal mass of thin renewing roots. The roots’ structure allow the plant to withstand saline conditions in the soil. They have no root hairs, but they have a short absorbent area, directly behind the root hood and are covered by a thick impermeable hypodermis. The seashore has a supply of fresh water: when a hole is dug in the sand, the salt water which seeps in is covered by a thin layer of fresh water (lighter) which is sufficient for the coconut palm. Its roots do not reach the seawater, but only go down as far as the fresh water. When it rains, the level of fresh water in the sand of tropical beaches rises.

LEAVES – The leaves are pinnate, 10-15 of them grouped in a dense cluster at the top of the trunk, 4-6 m in length with a robust petiole. Each weighs over 15 kg and has a life span of around 5 years. When they die, they fall to the ground leaving a scar on the trunk. A new leaf then begins to grow taking the place of the old one.

FLOWERS – The flowers, produced all year round, are unisexual. Inflorescences form with branched spikes, about 80 cm in length. On maturity the butter-yellow protective spathe breaks off. These inflorescences are situated in the axil of the leaves. The female flowers are situated below the male flowers which are more numerous (200-300). The male flowers, small and yellow, open first; female flowers become receptive and produce nectar only after the pollen has fallen. Pollination within the inflorescence or between inflorescences of the same tree is rare: normally cross-pollination occurs. The flowers are visited by wasps and other insects, but as the pollen is dry, wind-pollination can also occur.

FRUITS – Large multi-carpel drupe, globular with three faces, of varying colour, which take a year to ripen. They have a smooth and relatively thin epicarp; extremely fibrous and airy mesocarp which allows the drupe to float; the endocarp is the ligneous, hard and very resistant inner layer of the fruit. The oleaginous white albumen is 1-2 cm thick. In unripe fruit the endocarp contains a liquid endosperm: coconut milk. The three crests and the three germination pores at the base of the endocarp represent the three carpels and the three loculi of the ovary. Two of the ovules abort, but the third remains functional. Its embryonic sack widens and fills with coconut milk. The endosperm begins to form six months after fertilisation. The testa is the thin brown rind between the endosperm and the endocarp. The embryo, small and undifferentiated when the fruit falls, gradually extends below one of the pores.


PROPAGATION
SEED – The seed, one of the largest known, is the coconut itself. In markets in temperate zones, we generally buy only the seed of the coconut palm, with its adherent internal woody layer: the stone and the whole is commonly known as the coconut. The whole fruit, however, is not a nut (i.e. a dry dehiscent fruit) but a drupe (which is typically a fleshy fruit, indehiscent, with a stone containing only one seed), atypical, because the mesocarp is fibrous instead of fleshy.

The seeds must be sown whole while still full of milk. They are planted in a horizontal position and covered about halfway up by soil. The soil must be kept humid. Germination occurs after 1-2 months. When the plants are about 6 months old they are transferred to nurseries where they are left to grow for 3-4 years before being re-planted. They can also be directly sown in the field. In natural conditions, germination occurs after the fruit has been in the soil for a number of weeks, when the humid air penetrates and awakens the dormant seed. The white roots develop from the side of the fruit turned towards the peduncle. The first root emerges from one of the three germination pores, points where the endocarp is thin, taking with it a bud, wrapped in the first green leaf, and taking its course through the fibrous mesocarp which opens out, where the buds and roots begin to grow.