FLORA

Flora

The island continent Madagascar has no less than five spacious climate zones. Each climate zone contains specific vegetation types. With an abundance of approximately 13 000 species, the big island is simply an inexhaustible treasure trove of plant life. Every year new species are being discovered. In Germany, by contrast, there are only about 1,500 plant species.
Among the 210 domiciled plant families, there are 5 families that are endemic in Madagascar. These are Asteropeiaceae, Barbeuiaceae, Pysenaceae, Sarcolaenaceae, Sphaerosepalaceae. The Didiereaceae family was still counted as an endemic plant family for Madagascar until a few years ago, when a representation of this group was discovered in South Africa. As to the biodiversity, the Madagascan flora is characterised by high endemism. Over 80% of the Madagascan plant species are endemic.

The orchid families with over 1,000 species, the coffee plants with roughly 400 species and the grasses with about 300 species are particularly diverse. Madagascar's world of succulents is also particularly interesting. The six endemic baobab species, the kalanchoe species, the thickened stem plants of the Pachypodium species, the Madagascan aloe species and the spurge family flourish in the dry areas of the highlands, in the South and in the dry part in the North of Madagascar.

Baobabs and other trees

Due to the separation of Madagascar from the supercontinent Gondwana roughly 150 million years ago, the development of the flora and fauna in Madagascar has been independent and unhindered. The flora of Madagascar contains a multitude of endemic species. Over 75% of the plant species in Madagascar are found exclusively on the island.

One of the most fascinating trees of the island is the baobab. In the native language, the baobab is called « Reniala », which means « mother of the forest ». This description is due not only to the size of the tree but also to its age. The baobab can live up to a thousand years, or several thousand years as some scientists declare. There are eight baobab species throughout the world. Seven of them can be found in Madagascar and six of them exist only in Madagascar: Adansonia grandidieri, Adansonia za, Adansonia rubrostipa, Adansonia madagascariensis, Adansonia perieri, Adansonia suarezensis.

Only the Adansonia digitata grows both in Madagascar and in Eastern Africa and Adansonia gibbosa can only be found in Australia. The occurance of the Adansonia species on these continents indicates a former land connection between Africa, Madagascar and Australia. The baobab is a plant species of the Adansonia genus, a subfamily of the spurge family (Bombacoideae). However, in the new classification, the baobab ranks among the mallows (Malvaceae). Baobabs are stem succulents, which means they store water in their stem. They don’t provide strong wood because of the fibrous nature of their stems as a result of the water retention. The circumference of a baobab can be up to 30 m and the diameter up to 9 m. The baobabs near Andavadoaka, for example, are known for their thick trunks.

During its evolution, this fantastic tree has developed the ability to survive in dry areas, too much humidity is actually harmful to the baobab. This is the reason why the baobab of Morondava is endangered. Due to the rice cultivation nearby, the region has become too wet for the baobab. Some of the baobabs of this region have already been victims of these new conditions. In order to limit the water loss, the baobabs only show their leaves for a short period of time. During the dry period the leaves are shed. The blossoms of the baobabs appear in a great variety of colours, anywhere from white to yellow to dark red. The bloom depends on the species. The blossoms are mainly pollinated by various bat species. The fruits of the baobab, with a length of 40 cm and a diameter of 15 cm, can contain a dozen seeds. The fruit, being rich in vitamins, is eaten by the native population.

One of the most often photographed landscapes of Madagascar is undoubtedly the Avenue of the Baobabs. The Avenue lies north of the city of Morondava. There, you can find the endemic species Adansonia grandidieri. In Toliary and its surroundings, there are three endemic species (Adansonia rubrostipa, Adansonia za, Adansonia madagascariensis) and only in Mahajanga do you find the Adansonia digitata. In the North, the two species, Adansonia suarezensis and Adansonia perrieri, are commonly found.

Travellers’ tree

While « the roots of heaven », another description of the baobabs, have conquered the dry Northern, Southern and western parts of the country, the traveller’s tree dominates in the highlands and the rain-rich region of Madagascar. The Ravenala (Ravenala madagascariensis), which means “forest leaves”, is a species which originated in Madagascar. However, it is still cultivated as an ornamental plant in all tropical and subtropical regions. Due to the similarity of its leaves, it was mistakenly designated a banana plants. 

It is often also mistakenly defined as a fan palm. The traveller’s tree is part of the strelitias. It has many practical applications. The walls of cabins are made from the leaf stalks and the roofs are covered with its leaves. Water is stored in the stem base and the big leaves can be used as umbrellas. Therefore, the Ravenala is also called the « traveller’s tree ». Because Ravenalas grow relatively fast and are fire-resistant, they continue to flourish, despite the widespread destruction of their habitat through clear-cutting and burning. The National Road 2 in the East of the island leads along a Ravenala forest that has replaced the original rainforest. The traveller’s tree is also the symbol of our national airline.

The palm world of Madagascar

The palm world of Madagascar is characterised by a high rate of endemism. From the approximately 120 registered palm species, 80% are endemic. The best known species are: Dypsis acuminum, Dypsis baronii, Dypsis occidentalis, Dypsis onilahensis, Dypsis lokohoensis, Dypsis perrieri, Dypsis decaryi, Dypsis lutescens, Dypsis bonsai and Dypsis pumila. Each vegetation zone of Madagascar has its own palm species. The dry West is home to the Bismarckia nobilis, which is named after the Prussian chancellor Otto von Bismarck. With its broad leaves, this species is one of the fan palms. The climatic transitional zone near the Andohaela National Park is the habitat of the endemic triangle palm (Dypsis decaryi).

The Marojejy National Park in the North of Madagascar is known for its endemic Marojejya insignis.

About 40 types of rosewood are considered precious woods, of which only one can be defined as endemic. Rosewood trees belong to the Dalberia genus. Its usage is subject to strict legal regulation. This is, in part, an effort to educate the native population, which still uses the rosewood as firewood for cooking, and increase the awareness of environmental considerations. The exportation of precious woods is prohibited by law, a measure which is supported by the European law. Unfortunately, the illegal trade of precious woods still exists. In 2009, during the political unrest, tons of rosewood was brought from Madagascar to China. Madagascar is a paradise not only for botanic lovers but also for zoologists.  Scientists consider Madagascar as one of the most biodiverse countries in the world. This high biodiversity is being acutely threatened and requires effective protection, on the one hand by the international community and on the other by improved awareness of the native people.

Medicinal plants

Madagascar flora is rich in medicinal plants. The Katrafay (Cedrelopsis grevei), belonging to the Rutaceae, is worth mentioning. This tree grows to a height of 12 to 15 m and can be found in the dry areas of the South and Southwest of Madagascar. The bark is used to make a tea which is used to stave off fatigue. From the leaves, essences are obtained which have a refreshing effect in shower lotions. Positive effects on the libido and potency are accredited to both the leaves and the bark. The white wood of the Katrafay is used in the modern furniture industry. The apocynaceae family includes about five species. You can recognise them by their five-lobed calyx with colours varying from white to pink to purple.

The Madagascar evergreen belongs to those plants that bloom nearly the entire year. The native people make use of the pharmaceutical qualities of this plant. They are used to combat diabetes and high blood pressure. Generally, the Madagascan evergreen is very adaptable, so the species are widespread. In the dry region, the Catharantus roseus species is cultivated and exported for the European pharmaceutical industry. Vinblastin and Vincristin, two alkaloids extracted from this plant, are used in cancer therapy. In Europe, the Madagascan evergreen is used as an ornamental plant today. It is considered a poisonous plant but its toxicity is low. Other species of the Madagascan evergreen are: Catharantus lanceus, Catharantus longifolius, Catharantus ovalis and Catharantus scitillus.

Madagascar’s orchids

Beside the grasses and coffee plants, the orchids, with about one thousand registered species, belong to the biggest plant family of Madagascar. About 90% of the orchid species are endemic. Each of the different vegetation zones has its own species that can vary in their colour tones, sizes and ways of living. To help illustrate the diversity, we offer the following virtual journey to the most beautiful orchids of Madagascar. Let yourself be caught up by the attraction of the Hanitriniala, « the fragrance of the forest ».

The endemic « star of Madagascar » belongs to the orchid species with big magnificent blossoms. It grows primarily in the woods of the sand coasts, both terrestrially and epiphytically. Its scientific name is Angraecum sesquipedale. The word sesquipedale means 1,5 feet referring to the spur of 45 cm length. In Darwin’s time, the procedure of pollination was not known. Darwin’s contemporaries doubted in his theory of a hawk moth with a snout 30 cm in length. However, the hawk moth was discovered after Darwin’s death: Xanthopan morgani praedicta. During the bloom from June to November, the pure white blossoms spread their delicate scent when darkness falls. The Angraecum sesquipedale often grows in the same region as Angraecum eburneum, another resident of the woods of the sand coasts, and prefers to stay local, which means it is strongly affected by the deforestation. 

The Angraecum eburneum blooms in the dry period from July to September and in contrast to the Angraecum sesquipedale, it also blooms in houses when cultivated there. The Disperis, Calanthe and Cynorkis genera belong to the famous ground orchids. The genus Disperis includes delicate ground orchids that only reach 15 cm to 30 cm. There are about 22 species of this genus in Madagascar. Disperis literally means « two pockets », referring to the two opposing leaves.  The colour of the blossom varies from white to pink and purple. The range of the genus Disperis reaches from Ambositra and Andringitra over the mountains of Tsaratanana to Sambirano. The most commonly occurring species are: Disperis trilineata, Disperis similis, Disperis tripetaloïdes, Disperis erucifera and Disperis hildebrantii. The Disperis similis genus can be found in the region of the central plateau, while the Disperis trilineata is more typically domestic in Northern Sambirano. The Disperis tripetaloïdes genus grows in the region of Bemaraha and Taolagnaro.

Some orchid species have adapted to their surroundings in such a way that they cannot survive outside their habitat. For example, the Solenangis aphylla species can only be found in the region of the coastal forest. This orchid, typically found in the dry forest, belongs to the aphyll species. The leafless orchid, with the small and nondescript blossoms, is characterised by a strongly developed root mass that undertakes the functions of both photosynthesis and nutrient intake.

A lot of orchids are focused on their host plant. In the region with high precipitation of Maroantsetra, the orchid Eulophiella elisabethae grows on the palm Vohinitra utilis, and in the coastal forest of Palmarium in Akanin’ny Nofy, the species Cymbidiella humbloti grows in the leaf sheaths of the Raffia palm (Raphia ruffia). It is known as the « black orchid » due to its decorative beautiful blossoms. The question remains whether this association is due to symbiosis, or if the orchids could survive without their host plants.  The Cymbidiella flabellate species, which smells like vanilla, grows at the banks of the channel of Pangalane and in the heather of erica or phillipia.

The small island « Ile aux nattes”, on the southern tip of Sainte Marie is home to the queen of the orchids.  The big orchid species, with its purple blossoms blooming in October, grows exclusively on the common screwpine (Pandanus utilis) and cannot survive in houses. Its florescence can reach more than 1 m. As its leaves are similar to the leaves of its host plant, the orchid only becomes visible when the large blossoms stand out against the leaves.  If you are in Madagascar in October, you should not miss the chance to marvel at the most beautiful orchid of the island.  The vanilla prospers both in the humid and dry regions of Madagascar. The best known species is the Vanilla planifolia. Nowhere else in the world is vanilla cultivated in such quantities as in the northeast coastal region of Madagascar: Sambava, Antalaha, Andapa and Vohemar. The wild vanilla « Vanilla decaryana » blooms in September in the Kirindy Forest.

Succulents

Madagascar’s pachypodium

The Pachypodium belongs to the Apocynaceae. The word pachypodium is a combination of the words pachy (fat) and podium (foot). Actually, the pachypodium is a thickened stem plant. Beside the baobabs and moringa, the pachypodium is the most common representative of the stem succulents. The Pachypodium lamerei can be bought as potted plant in Germany. Pachypodium rutenbergianum was first described by the German botanist Rutenberg in the 19th century. Whereas the African species only develop pure white or white and red lined blossoms, the Madagascan species have a very wide range of colours. The blossom colours vary from region to region. The white-blooming species can be found in the western region of Madagascar. Mistakenly named as a dwarf baobab, the bulbous and small Pachypodium horombense, Pachypodium rosulatum, Pachypodium densiflorum and Pachypodium brevicaule can be recognised by their yellow blossoms. They live almost exclusively in the region of the central plateau. One group comes from the region with low precipitation in the northern tip of Madagascar. Two regional pachypodium groups have red blossoms: Pachypodium windsori and Pachypodium baroni.

Madagascar’s aloes

With about 300 species, the aloes are spread over the entire African continent, except the Sahara and North Africa. Madagascar is home to roughly 60 aloe species. Another aloe species grows in Comoros. In Madagascar, they are spread over three territories. The smaller, rosette-forming and stemless species grows in the central region. The representatives of this group are the Aloe capitata, Aloe itremonsis and Aloe contingua. 

The Aloe suarezensis species, which can be found in the North near the Windsor Castle and the French Mountain, grows to a medium size. The third bush and tree-like group grows in the brush forests of the Androy landscape. The stem-building species appear in the thorn bush and Didiereaceae forest.  Aloe vahombe is cultivated by the Antandroy, often as ornamental plants in their small gardens in front of their cabins. Other representatives of this group are: Aloe voatsanda, Aloe divarigata and Aloe helenae. The beautiful Aloe suzannae that is only represented by 10 individuals is severely endangered. Aloes are popular for their therapeutic qualities.  The species Aloe macroclada and A. vahombe are used for the treatment of kidney stones and stomach problems.

Madagascar’s didiereaceae

This family was first described by the French botanist Alfred Grandidier. Before the discovery of a similar genus at the African continent, the whole family of four genera and 11 species had been regarded as endemic for a long time. The Androy landscape of the South is the exclusive location of this fascinating and unique plant. A night walk through the Didiereaceae forest of the private reserve of Berenty is probably one of the most impressive experiences of a trip through Madagascar. The Antandroy tribe uses two species to build their cabins: Alluaudia procera and Alluaudia ascendens. Further common representatives of this family are: the Didiera trolli, Didiera madagascariensis and Decarya madagascariensis.

Madagascar’s kalanchoe

These belong to the leaf succulents. Water is collected and stored in the fleshy leaves during the rainy period. The kalanchoe species are characterised by their vegetative reproduction form. Its largest representative is the endemic Chalanchoe beharensis. It can reach a height of up to 3 metres. Due to the shape of its big leaves, this species is also called Napeleon’s hat. The stem marked by leaf scars is characteristic of this species. On the road to the Berenty private reserve, you come across one single Napoleon’s hat. A lot of other kalanchoe species flourish in the dry south of Madagascar. Chalanchoe grandidieri, Chalanchoe arborescens, Chalanchoe. millotii, Chalanchoe tubiflora and Chalanchoe schizophylla are the most common representatives in this part of the country.

Madagascar’s euphorbia

The euphorbia belongs to the spurge family. The name is derived from the personal doctor of King Juba of Mauritania (50 B.C.), Euphorbos.  The Madagascan euphorbia differs from the African spurges by the lack of tree-like representatives. In order to save water, the euphorbia has only small leaves in the southern region of Madagascar. Representatives of this genus are: Euphorbia leucadendron, Euphorbia laro, Euphorbia oncoclada and Euphorbia stenoclada. An endemic euphorbia species grows in the northern tip of Madagascar: Euphorbia ankarensis. It grows in the Ankarana mountains and is similar to the Euphorbia millii. Unlike the above mentioned euphorbia, the species Euphorbia antso produce reduced foliage.

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