Seychelles palm
| Seychelles palm | ||||||||||||
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Seychelles palm ( Lodoicea maldivica ) |
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| Systematics | ||||||||||||
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| Scientific name of the genus | ||||||||||||
| Lodoicea | ||||||||||||
| Comm. ex DC. | ||||||||||||
| Scientific name of the species | ||||||||||||
| Lodoicea maldivica | ||||||||||||
| ( JFGmel. ) Pers. |
The Seychelles palm ( Lodoicea maldivica ), also called Seychelles nut, is an endemic (endemic = distributed in a limited area ) palm species that occurs exclusively in the Seychelles . It is restricted to the two islands of Praslin and Curieuse , but here it is partly pure stocks . Its seeds are the largest in the plant kingdom.
features
The Seychelles palm is a strong, often tall, solitary, unreinforced fan palm . It is dioecious, separate sexes ( diocesan ) and flourishes several times. The trunk is erect, slightly expanded at the base and covered with inconspicuous rings of leaf scars. It reaches heights of 24 meters with trunk diameters of up to 50 cm. The crown forms a hemisphere and consists of around 15 to 20 leaves.
The palm trees grow very slowly and can probably reach an age of 200 years.
The number of chromosomes is 2n = 34.
leaves
The leaves are folded in duplicate, costapalmatically and remain on the plant after they die (marzescence), in taller palms they fall off under their own weight. The leaf sheath soon tears open opposite the petiole , and a triangular crevice forms at the base of the stalk. The petiole is 1.8 to 3.6 m long. It is strong, with a deep groove on the top and rounded on the underside. The underside is covered with small black dots and irregularly haired. The midrib (costa) is long, gradually narrowing and extends almost to the end of the blade. The leaf blade is about as long as the petiole. It becomes 5.4 m long and 3.6 m wide. It is stiff, wedge-shaped at the base, and divided into simply folded segments for about a quarter to a third of its length. These are briefly in two parts (bifid), the free ends often hang down. The top is shiny, smooth, the bottom is blunt with thick hairs along the abaxial folds. The central ribs are clearly visible on the underside.
Inflorescences and flowers
The inflorescences are massive, arise between the leaves (interfoliar) and are shorter than the leaves between which they hang. Male and female inflorescences are significantly different.
Male inflorescences and flowers
The male inflorescences have a short, narrow inflorescence stalk. They are often unbranched and end in a single rachilla (flower-bearing axis) or in two to three rachillae arranged like fingers. The cover sheet is short, two-keeled and split ventrally, but has a long, closed triangular tip. There is a bract on the peduncle that hides the stem. It is tubular and split ventrally across the middle and forms a long, firm, pointed beak. The rachillae are massive, cat-like and have several large, empty cup-like bracts at the base. Above these are very tough, leathery bracts in a spiral arrangement, which are laterally fused and form large pits distally. In each of these pits there is a backward-curved coil of 60 to 70 male flowers .
Every male flower has a fibrous bractole. The three sepals are fused into an asymmetrical tube, the tips are free, imbricat and asymmetrical. The crown consists of a long, stem-like base and three elongated lobes that are unevenly wide and do not close laterally around the androeceum . The tips of the tips are thick, rounded, and imbricat. A flower contains 17 to 22 stamens that are on the surface of an elongated receptaculum . The filaments are short, broad, the anthers elongated, the tips curved backwards, and latrors. The rudiment of the stamp is columnar and in three parts.
The pollen is ellipsoidal and bisymmetrical. The germ opening is a distal sulcus. The longest axis measures 61 to 68 microns.
Female inflorescences and flowers
The female inflorescence is unbranched. It has a cover leaf and two (rarely up to three) tubular bracts on the peduncle. These are split ventrally and have a long, pointed end similar to that of the male inflorescences. There is only one rachilla, which is a direct extension of the peduncle. It is short, wide, curved in a zigzag shape and narrowed towards the end. It has several empty cup-shaped bracts. The following bracts are large and each have a female flower.
The female flower is the largest known flower in the palm family. The flowers are sessile, ovate and have two large, cup-shaped bractoles at the base. The three sepals are free, imbricat, leathery, rounded and thicker at the base. The three petals resemble the sepals. The staminodes are triangular, low, fused at the base and have several pointed ends. The gynoeceum is egg-shaped, consists of three carpels, is three years old with a central, three-lobed septal nectarium . The stylus area is broad, triangular and fibrous. The three scars are short and bent back. The ovules are beaked, orthotropic, laterally winged and have two lateral bodies, possibly undeveloped ovules.
Fruits and seeds
The fruit is very large and is up to 50 cm long. It is egg-shaped and pointed. It contains one (rarely up to three) seeds. The exocarp is smooth, the mesocarp fibrous. The endocarp consists of one to three bilobed, thick and hard stone cores .
The seed is the largest known plant seed. It is bilobed like the stone core, the endosperm is thick, relatively hard, hollow and homogeneous. The embryo sits apically in the sinus between the two lobes.
One seed weighs 10 to 25 kg. Since a fruit can contain up to three seeds, their weight is up to 45 kg.
A palm usually only produces one fruit per year. The fruit takes up to seven years to ripen.
Distribution, locations and endangerment
The Seychelles palm is endemic to the Seychelles . Today it is limited to the slopes and valleys of Praslin and Curieuse . In the past it also occurred on the neighboring islands. It is absent in the coastal plains and on the mountain ridges.
It grows on almost all soils. It shows its best growth in forests above deep, well-watered valley floors. Here the Seychelles palm forms almost pure stands or mixed stands with other palms (such as ceilingia nobilis ) or with the screw palm Pandanus hornei . These stands are characterized by low undergrowth, which is due to the lack of light and the high amount of leaf litter. Epiphytes such as lichens grow in the trunk cortex . Ferns can grow in the corolla around the inflorescences . Some endemic animal species are closely connected to the palm stocks: the small vasa parrot ( Coracopsis nigra barklyi ), Hypsipetes crassirostris and the three gecko species: Phelsuma sunbergi , Phelsuma astriata and Ailuronyx seychellensis .
In 2011 the IUCN stated the total population as 8,282 adult individuals. Most occur in three subpopulations: in the Vallée de Mai , in Fond Ferdinand and on Curieuse.
Over the past three generations, the population decline is estimated to be around 30%. Reasons for habitat loss are natural fires and slash and burn, infrastructure expansion, introduced pathogens and parasites and the gathering and poaching of nuts and seeds. The degree of endangerment is classified as "endangered".
Systematics
The genus Lodoicea is placed within the family Arecaceae in the subfamily Coryphoideae , Tribus Borasseae and Subtribus Lataniinae. The genus is monotypical, it consists of the only species Lodoicea maldivica . Your sister group may be the Borassodendron and Borassus group .
In the World Checklist of Selected Plant Families of the Royal Botanic Gardens, Kew, only the species Lodoicea maldivica is recognized.
The genus was named after the French King Louis XV. named.
The specific epithet maldivica refers to the Maldives and comes from a time when the seeds were only known from specimens washed up in the Maldives.
use
The leaves are used locally for roofing and wickerwork. Palisades and water troughs are made from the wood. Eating dishes are made from the seeds. They are also used as a substitute for ivory (so-called vegetable ivory ). Cushions are filled with the fluff of young leaves. Selling the nuts to tourists is a significant source of income, although the total number of fruits is limited.
The pulp is edible.
supporting documents
- John Dransfield, Natalie W. Uhl, Conny B. Asmussen, William J. Baker, Madeline M. Harley, Carl E. Lewis: Genera Palmarum. The Evolution and Classification of Palms . Second edition, Royal Botanic Gardens, Kew 2008, ISBN 978-1-84246-182-2 , pp. 323-325.
Individual evidence
- ↑ a b c d e f Robert Lee Riffle, Paul Craft: An Encyclopedia of Cultivated Palms . Timber Press, Portland 2007, ISBN 978-0-88192-558-6 , pp. 381f.
- ^ A b H. Walter Lack, William J. Baker: Die Welt der Palmen / The World of Palms . Botanical Garden and Botanical Museum Berlin-Dahlem, Berlin 2011, ISBN 978-3-921800-69-0 , p. 56
- ^ P. Barry Tomlinson: The uniqueness of palms . Botanical Journal of the Linnean Society, 2006, Volume 151, pp. 5-14.
- ↑ a b c Lodoicea maldivica in the endangered Red List species the IUCN . April 14, 2012 accessed.
- ↑ Rafaël Govaerts (ed.): Lodoicea. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved April 14, 2012.
- ↑ Lotte Burkhardt: Directory of eponymous plant names - Extended Edition. Part I and II. Botanic Garden and Botanical Museum Berlin , Freie Universität Berlin , Berlin 2018, ISBN 978-3-946292-26-5 doi: 10.3372 / epolist2018 .
Web links
- Lodoicea maldivica onthe IUCN Red List of Threatened Species .
- Plant of the month November 2002 from the University of Bonn
- History of the Seychelles nut