Seychelles - A Noah's Ark for Palms

In marked contrast to the preceding, globe-trotting Dr. Teege takes us on a trip to the Indian Ocean, where the word frost isn't even in the dictionary.
Dr. Maria-Jutta Teege, Alwin-Mittaschplatz 12, D67063 Ludwigshafen
Chamaerops No. 19, published online 23-07-2002

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Left: The figure (bottom left) provides scale for stiltrooted Verschaffeltia splendida. Mahé B.G.
Right: Lodoicea maldivica - biggest seed in the vegetable kingdom

About 100 million years ago, during the Cretaceous age, the old continent of Gondwana began to break up into several pieces which separated continuously in the vast ocean and became the fundamental parts of the now well known continents of South America, Africa with Madagascar, Antarctica, India and Australia. It was the age when the dinosaurs diminished while mammals and birds began their triumphal march of evolution. The land plants having been dominated by mosses, ferns and conifers, now produced the first Monocotyledons (today they include the palms) and Dicotyledons (today they include most of our flowering plants).

When Gondwana broke into pieces it happened that some small parts of the continental mass got lost in the ocean without any connection to bigger continents. We can find them now as tiny granitic islands close to the equator in the Indian Ocean between Africa and India: the Seychelles. The biggest, Mahè, with 148 km2 and mountains up to more than 900m - the smallest, only rocks scattered in the sea. No other oceanic archipelago consists of continental rock (granite) as they do. Usually the substance of oceanic islands is volcanic material or coral rock. The uninhabited Seychelles, densely covered with tropical jungle, would remain unspoilt until 1770 when the settlement by French settlers and their African slaves began.

The first impression of all travellers and settlers who arrived was their amazement at the abundance of palms, especially on Praslin, the second biggest of the islands, with 59 km2 and mountains about 500m high. Because of this, Praslin was previously known as 'L'isle de Palme' or 'Palm Island'. Later botanists found out that it was not only the great number of palms that was so striking but also their special kinds. Quite apart from the abundant Coconut palms (Cocos nucifera) along the island's shores and some other palms imported by man, these tiny islands are home to six palm species none of which can be found anywhere else in the world. These endemic Seychelles palms differ so much from each other and from all other palm kinds that each had to be put in its own genus!

The isolation of the Seychelles for an unimaginable period of time must be the reason for the independent way of evolution which their original 'Gondwana' palm had taken. Probably no other undamaged palm seed was able to reach the isolated Seychelles by wind or water, except Coconuts which do not lose their ability for germination while floating in the sea.

The most interesting of the endemic Seychelles palms is the famous "Coco-de-mer" (Lodoicea maldivica). Long before the Seychelles were discovered by Europeans, a fruit of immense size, a nut with partly decayed seed, was occasionally brought by the sea to other shores of the Indian Ocean. Nobody knew where they came from or on which tree they had grown. So people believed that there was a tree in the middle of the ocean and the fruits were thought to be a medicine and an aphrodisiac. High prices were paid for them. It was in 1768 that the surveyor Barrè discovered the tall fan palms, which bore these fruits up to 20 kg in weight on the slopes of Praslin's valleys. Under the smooth skin lies the biggest and heaviest seed of the whole vegetable kingdom, the double shaped Coco-de-mer. It is difficult to imagine any advantage for evolution these heavy fruits can have, for they can be distributed neither by animals nor by wind or water.

Today these trees are restricted to some places of Praslin and the small neighbouring island of Curieuse. It is an impressive experience to enter Praslin's National park 'Vallée de Mai' and to walk in the moist and gloomy air between hundreds of Coco-de-mer palms. The rustling and clashing of their huge and heavy leaves is the only sound in this archaic environment. Ripening fruits of different sizes can be seen in bunches on the female palms and long brown catkins with small yellow flowers on the male trees. They are dioecious (male and female flowers are on separate plants).

But in this National park of about 46 acres in the midlands of Praslin live more than Cocode-mer palms, giving a general idea of the natural vegetation of this island.

In contrast to the humid and dark valleys there are the upper slopes of the hills and mountains which get the full tropical sun. Here thrive the most beautiful of all Seychelles palms: Deckenia nobilis. The straight slender stem ends with a crownshaft and bears regularly feathered pinnate leaves of a light green. Young individuals have strong yellow spines around the stem, probably to protect the delicate 'palm heart', the upper shoot, from being eaten by climbing animals. Nevertheless humans used to collect them in earlier years and called the palm "palmiste" .

Close to a small watercourse at the most humid spot of the area we found two other palms in the Valle de Mai: Nephrosperma van houtteanum with pinnate leaves but without crownshaft, and Verschaffeltia splendida with irregularly split but pinnately ribbed leaves. A peculiarity of Verschaffeltia is its stilt roots. The main root disappears when the stilt roots begin to grow, and ultimately they carry the heavy (up to 20 m high) palm one or two metres above the surface of the ground. This seems to be an adaptation to growing on a swampy ground.

A further endemic palm is Phoenicophorium borsigianum, well recognizable by its undivided but marginally lobed leaves. The young individuals are provided with long and thin black spines. These palms are widely dispersed now over Praslin and other Seychelles islands. They are planted as ornamentals and the leaves were used for thatching. Phoenicophorium is probably the mostly cultivated Seychelles palm, and its scientific name itself is a curiosity. The translation means 'thief palm', and indeed, a thief stole one from the Royal Botanic Gardens at Kew in England in the 19th century, when they were a precious rarity in Europe.

The last of the Seychelles palms does not occur on Praslin but on the higher slopes of Mahé and Silhouette. The mountain rain forest at 600 to 800 m above sea level is the place for Roscheria melanochaetes, and it is a challenge for the palm enthusiast to look for this palm in the steep and impenetrable mountain area without road or footpath. Not even the Botanic Gardens in Mahé has one planted.

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