Double Coconut, sea coconut or Coco de mer

Botanical Name: Lodoicea maldivica

English: Double Coconut Palm, double coconut, the sea coconut, love nut,  coco fesse, or Seychelles nut.

Malayalam: Aklarithenga (അക്ളാരിത്തേങ്ങാ, അക്ലാരിത്തേങ്ങാ

)

French: Coco de mer. The name coco de mer is French, and means "coconut of the sea".

Lodoicea, commonly known as the sea coconut, coco de mer, or double coconut, is a monotypic genus in the palm family. The sole species, Lodoicea maldivica, is endemic to the islands of Praslin and Curieuse in the Seychelles. It formerly also was found on the small islets of St Pierre, Chauve-Souris and Ile Ronde (Round Island), all located near Praslin, but had become extinct there for a time until recently reintroduced. The name of the genus, Lodoicea, is derived from Lodoicus, the Latinised form of Louis, in honour of King Louis XV of France.

Maldive coconut, Lodoicea maldivica, this very large nut looks like two coconuts joined together, side by side. Maldive coconut has been classified very close to coconut, but is not related to the coconut. It belongs to the Borassoid group of palms. Maldive coconut is the world’s largest and heaviest seed, a single seed may be 12 inches long, nearly three feet in circumference and weigh 20kg. The Maldive coconut palms grow only on a small island named Praslin in the Seychelles. Plants of these nuts are tender and very slow-growing, the nut takes a year to germinate and another year to form its first leaf.

The tree generally grows to 25–34 m tall. The tallest on record, measured on the ground after felling, was 186 feet (56.7 meters) in total height. The leaves are fan-shaped, 7–10 m long and 4.5 m wide with a 4 m petiole in mature plants. However juveniles produce much longer petioles; up to 29' 6" (9 meters) or even 33 feet (10 meters). It is dioecious, with separate male and female plants. The male flowers are arranged in a catkin-like inflorescence up to 1 m long which continues to produce pollen over a ten-year period; one of the longest living inflorescences known. The mature fruit is 40–50 cm in diameter and weighs 15–30 kg, and contains the largest seed in the plant kingdom. The fruit, which requires 6–7 years to mature and a further two years to germinate, is sometimes also referred to as the sea coconut, love nut, double coconut, coco fesse, or Seychelles nut

Morphology

Leaves

The crown is a rather dense head of foliage with leaves that are stiff, palmate up to 10 m in diameter and petioles of two to four meters in length. The leaf is plicate at the base, cut one third or more into segments 4–10 cm broad with bifid end which are often drooping. A triangular cleft develops at the petiole base. The palm leaves form a huge funnel that intercepts particulate material, especially pollen, which is flushed to the base of the trunk when it rains. In this way, Lodoicea improves its nutrient supply and that of its dispersal-limited offspring.

Flowers

This species of palm is diecious (where male and female flowers are borne on different plants).

Inflorescence

Inflorescences are interfoliar, lacking a covering spathe and shorter than the leaves. The staminate inflorescence is catkin-like, one to two metres long and generally terminal and solitary, sometimes two or three catkins may be present. The pistillate inflorescences are also one to two metres long unbranched and the flowers are borne on a zig-zagging rachilla.

The clusters of staminate flowers are arranged spirally and are flanked by very tough leathery bracts. Each has a small bracteole, three sepals forming a cylindrical tube, and a three-lobed corolla. There are 17 to 22 stamens. The pistillate flowers are solitary and borne at the angles of the rachis and are partially sunken in it in the form of a cup. They are ovoid with three petals as well as three sepals. It has been suggested that they may be pollinated by animals such as the endemic lizards which inhabit the forest where they occur. Pollination by wind and rain are also thought to be important. Only when Lodoicea begins to produce flowers, which can vary from 11 years to 45 or more, is it possible to determine the sex of the plant. The nectar and pollen are also food for several endemic animals e.g. bright green geckos (Phelsuma sp.), white slugs (Vaginula seychellensis) and insects.

Fruit

The fruit is bilobed, flattened, 40 to 50 cm long ovoid and pointed, and contains usually one but occasionally two to four seeds. The epicarp is smooth and the mesocarp is fibrous. The endosperm is thick, relatively hard, hollow and homogenous. The embryo sits in the sinus between the two lobes. During germination a tubular cotyledonary petiole develops that connects the young plant to the seed. The length of the tube is reported to reach about four metres. In the Vallee de Mai the tube may be up to 10 m long.

Lodoicea was once believed to be a sea-bean or drift seed, a seed evolved to be dispersed by the sea. However, it is now known that the viable nut is too dense to float, and only rotted out nuts can be found on the sea surface,thus explaining why the trees are limited in range to just two islands.

Ripe interior (endosperm) of coco-de-mer is normally like jelly, not firm and white like cocos nucifera (coconut). Maldive coconut is also said to be a powerful aphrodisiac still used in Asian herbal medicine.

seeds

The seeds usually have two lobes and can weigh up to an enormous 30 kg.

The fruit contains usually one but occasionally two to four seeds. The mature fruit is 40-50 cm in diameter and weighs 15-30 kg, and contains the largest seed in the plant kingdom. The fruit, which requires 6-7 years to mature and a further two years to germinate.

Lodoicea was once believed to be a sea-bean or drift seed, a seed evolved to be dispersed by the sea. However, it is now known that the viable nut is too dense to float, and only rotted out nuts can be found on the sea surface, thus explaining why the trees are limited in range to just two islands.

The seeds germinate in about one year and must have available a thickness of the soil of at least 1,5 metres, as the hypocotyl which develops from the seed, and on which extremity stands the germ which will originate the first leaf, goes down up to this depth.

Pollination

The Double Coconut or Coco de Mer is unique among palm tree species in that there are distinct male and female palms. The female palms grow the fruits. The male palms are taller, more slender and have catkins growing on them. The small flowers on the catkins of the male palm have a strong scent, produce large amounts of nectar and are very small.

The flowers on the female tree produce a similar scent to the male flowers, but the scent is less strong. Only one flower is active on a female tree at any one time and then for only for a few hours each day. There has been some debate about how Coco de Mer palms are pollinated. It is now believed that their primary pollinator is a long legged fly, the Ethiosciapus bilobatus.

The Uses of Double Coconut or Coco de mer

Food Uses

The Double coconut or Coco de Mer fruit is edible, but is not commercially available due to the restricted distribution and difficulty in cultivating the plant.

The real purpose of the fruit, the edible part is the endosperm of the fruit that is succulent and a delight to the taste buds. In case of the immature seeds they tend to contain a jelly like substance that melts in the mouth with a sweet taste. This is treated as a delicacy and is enjoyed by the locals. In food, it is typically found as flavor enhancers for soups in southern Chinese cuisine, namely cuisine around the Canton country.

Medical Uses

Back in old times this plant was used for its medicinal properties that helped in wading off many life threatening diseases. The fruit is used in Ayurvedic medicine  like kashaya mridha sanjivini gulika, sidha medicines for diabetes, vomiting and libido and also in traditional Chinese medicine. The jelly-like flesh of Coco de Mer was considered to have medicinal properties.

History and mythology

Formerly Lodoicea was known as Maldive coconut. Its scientific name, Lodoicea maldivica, originated before the 18th century when the Seychelles were uninhabited. In centuries past the coconuts that fell from the trees and ended up in the sea would be carried away eastwards by the prevailing sea currents. The nuts can only float after the germination process, when they are hollow. In this way many drifted to the Maldives where they were gathered from the beaches and valued as an important trade and medicinal item. This association is reflected in one of the plant's archaic botanical names, Lodoicea callipyge Comm. ex J. St.-Hil., in which callipyge is from Greek words meaning 'beautiful buttocks'. Other botanical names used in the past include Lodoicea sechellarum Labill. and Lodoicea sonneratii (Giseke) Baill.

Until the true source of the nut was discovered in 1768 by Dufresne, it was believed by many to grow on a mythical tree at the bottom of the sea. European nobles in the sixteenth century would often have the shells of these nuts polished and decorated with valuable jewels as collectibles for their private galleries. The coco de mer tree is now a rare and protected species.

The natives of the Maldive islands have heard of the local name of Maldive coconut, as Thaavah Kaashi, but mysteriously many at present are not even aware of the shape of it. The local name Thaavah Kaashi has been in the Dhivehi vocabulary for centuries and hard shell of the Maldive coconut is still used in local medicine for sexual enhancement purposes

Plants Details In India

Scientists at the Indian Botanical Garden in West Bengal’s Howrah district have carried out artificial pollination of the only double coconut tree in India, which bears the largest seed known to science.

One of the rare and globally threatened species of palm, the double coconut ( Lodoicea maldivica) tree was planted at the botanical garden in 1894 and the artificial pollination is a result of decades of work by scientists of the Botanical Survey of India (BSI).

“The tree took almost a hundred years to mature and when it started flowering, we started looking for this particular palm species in this part of world. We collected some pollen from palms from Sri Lanka but could not successfully pollinate it. Finally, with the help of pollen from another tree in Thailand, the pollination process was successful,” BSI Director Paramjit Singh told The Hindu.

Research Paper

1. Chemical Characterization of Lodoicea maldivica Fruit by Sebastiani B1, Giorgini M2, Falcinelli S3. : Chem Biodivers. 2017 Aug;14(8). doi: 10.1002/cbdv.201700109. Epub 2017 Jul 6

Abstract

In the present study, we report the attempt to characterize the chemical composition of fruit kernel of Lodoicea maldivica coco nucifera palm (commonly named as 'Coco de mer') by gas chromatographic method. The analysis was performed by HS-SPME and GC/MS techniques to determine volatile aroma, sterol, and fatty acid composition profiles in the internal and external pulp of two distinct coconuts. Although no qualitative differences in flavour composition were observed between the two analysed coconuts and the relative two pulp parts, variations in the abundance levels of the prominent compounds have been recorded. The averaged quantity of total phytosterols, resulting from the two analysed 'Coco de mer' samples, was almost constant in both kernels coconut, being 24.5 μg/g (of dry net matter) for the external, and 26.9 μg/g (of dry net matter) for the internal portion. In both coconuts, the fatty acid pattern composition was characterized by seven saturated acids ranged from C14:0 (myristic) to C20:0 (arachidic) and two monounsaturated acids, the palmitoleic (C16:1, ω7) and the oleic (C18:1, ω9). Palmitic acid (C16:0) was the predominant one with an average contribution of about 49.0%, followed by pentadecanoic 16.5%, stearic (C18:0) 11.6%, and myristic (C14:0) 9.9% acids in all two examined kernel portions.

2. Molecular identification of Lodoicea maldivica (coco de mer) seeds by Chun-yin Makcorresponding author1 and Chuen-shing Mok : Published online 2011 Sep 30. doi: 1186/1749-8546-6-34

Abstract

The edible endosperm of Lodoicea maldivica with the common name of coco de mer is used in Chinese medicine for treating cough. Native to Seychelles, Lodoicea maldivica seeds have commanded high prices for centuries due to its scarcity. This study aims to develop a molecular identification method for the authentication of Lodoicea maldivica seeds. The PRK gene of Lodoicea maldivica was successfully amplified and sequenced for identification.A new molecular method for the identification of Lodoicea maldivica seeds in fresh, frozen or dried forms was developed.

complete plant

 youtube video  Link

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