The flora of Madagascar consists of more than 12,000
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
of plants, as well as a poorly known number of
fungi
A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from ...
and
algae. Around 83% of
Madagascar
Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...
's
vascular plants
Vascular plants (), also called tracheophytes () or collectively Tracheophyta (), form a large group of land plants ( accepted known species) that have lignified tissues (the xylem) for conducting water and minerals throughout the plant. They ...
are found only on the island. These
endemic
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...
s include five plant
families
Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Ideal ...
, 85% of the over 900
orchid
Orchids are plants that belong to the family Orchidaceae (), a diverse and widespread group of flowering plants with blooms that are often colourful and fragrant.
Along with the Asteraceae, they are one of the two largest families of flowerin ...
species, around 200 species of
palms, and such emblematic species as the
traveller's tree, six species of
baobab
''Adansonia'' is a genus made up of eight species of medium-to-large deciduous trees known as baobabs ( or ). They are placed in the Malvaceae family, subfamily Bombacoideae. They are native to Madagascar, mainland Africa, and Australia.Trop ...
and the
Madagascar periwinkle
''Catharanthus roseus'', commonly known as bright eyes, Cape periwinkle, graveyard plant, Madagascar periwinkle, old maid, pink periwinkle, rose periwinkle, is a species of flowering plant in the family Apocynaceae. It is native and endemic to M ...
. The high degree of endemism is due to Madagascar's long isolation following its separation from the African and Indian landmasses in the
Mesozoic
The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Cretace ...
, 150–160 and 84–91 million years ago, respectively. However, few plant lineages remain from the ancient
Gondwanan flora; most
extant plant groups immigrated via across-ocean
dispersal well after continental break-up.
After its continental separation, Madagascar probably experienced a dry period, and
tropical rainforest
Tropical rainforests are rainforests that occur in areas of tropical rainforest climate in which there is no dry season – all months have an average precipitation of at least 60 mm – and may also be referred to as ''lowland equa ...
expanded only later in the
Oligocene to
Miocene
The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...
when rainfall increased. Today, humid forests, including the
lowland forests, are mainly found on the eastern plateau where abundant rainfall from the
Indian Ocean
The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by t ...
is captured by an
escarpment
An escarpment is a steep slope or long cliff that forms as a result of faulting or erosion and separates two relatively level areas having different elevations.
The terms ''scarp'' and ''scarp face'' are often used interchangeably with ''esca ...
. A large part of the
central highlands, in the
sub-humid forests ecoregion, is today dominated by
grassland
A grassland is an area where the vegetation is dominated by grasses ( Poaceae). However, sedge ( Cyperaceae) and rush ( Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur na ...
s. They are widely seen as result of human landscape transformation but some may be more ancient. Grassland occurs in a mosaic with woodland and bushland, including ''
tapia'' forest, and
hard-leaved thickets on the high mountains.
Dry forest
Dry or dryness most often refers to:
* Lack of rainfall, which may refer to
**Arid regions
**Drought
* Dry or dry area, relating to legal prohibition of selling, serving, or imbibing alcoholic beverages
* Dry humor, deadpan
* Dryness (medical)
* ...
and
succulent woodland are found in the drier western part and grade into the unique
spiny thicket in the southwest, where rainfall is lowest and the
wet season
The wet season (sometimes called the Rainy season) is the time of year when most of a region's average annual rainfall occurs. It is the time of year where the majority of a country's or region's annual precipitation occurs. Generally, the sea ...
shortest.
Mangroves
A mangrove is a shrub or tree that grows in coastal saline or brackish water. The term is also used for tropical coastal vegetation consisting of such species. Mangroves are taxonomically diverse, as a result of convergent evolution in severa ...
occur on the west coast, and a variety of
wetland
A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (anoxic) processes prevailing, especially in the soils. The p ...
habitats with an adapted flora are found across the island.
The first human presence in Madagascar dates only 2000–4000 years back, and settlement in the interior occurred centuries later. The
Malagasy people
The Malagasy (french: Malgache) are an Austronesian-speaking African ethnic group native to the island country of Madagascar. Traditionally, the population have been divided by subgroups (tribes or ethnicities). Examples include "Highlander" ...
have used the native flora for various purposes, including food, construction, and medicine. Exotic plants were introduced by early settlers, later traders and
French colonialists, and many have become important to
agriculture
Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled people t ...
. Among them are
rice
Rice is the seed of the grass species '' Oryza sativa'' (Asian rice) or less commonly ''Oryza glaberrima'' (African rice). The name wild rice is usually used for species of the genera '' Zizania'' and '' Porteresia'', both wild and domesticat ...
, the staple dish of
Malagasy cuisine grown in
terraced fields in the highlands, and
greater yam,
taro
Taro () (''Colocasia esculenta)'' is a root vegetable. It is the most widely cultivated species of several plants in the family Araceae that are used as vegetables for their corms, leaves, and petioles. Taro corms are a food staple in Afri ...
,
cowpea
The cowpea (''Vigna unguiculata'') is an annual herbaceous legume from the genus ''Vigna''. Its tolerance for sandy soil and low rainfall have made it an important crop in the semiarid regions across Africa and Asia. It requires very few inputs, ...
, and
plantain
Plantain may refer to:
Plants and fruits
* Cooking banana, banana cultivars in the genus ''Musa'' whose fruits are generally used in cooking
** True plantains, a group of cultivars of the genus ''Musa''
* ''Plantaginaceae'', a family of flowerin ...
. Plantation crops include
litchi
Lychee (US: ; UK: ; ''Litchi chinensis''; ) is a monotypic taxon and the sole member in the genus ''Litchi'' in the soapberry family, '' Sapindaceae''.
It is a tropical tree native to Southeast and Southwest China (the Guangdong, Fujian, ...
,
cloves,
coffee
Coffee is a drink prepared from roasted coffee beans. Darkly colored, bitter, and slightly acidic, coffee has a stimulating effect on humans, primarily due to its caffeine content. It is the most popular hot drink in the world.
Seeds of ...
, and
vanilla
Vanilla is a spice derived from orchids of the genus ''Vanilla (genus), Vanilla'', primarily obtained from pods of the Mexican species, flat-leaved vanilla (''Vanilla planifolia, V. planifolia'').
Pollination is required to make the p ...
, the latter one of the country's main export produce today. More than 1,300 introduced plants are known, of which around 600 have become naturalised, and some
invasive.
Human population growth and economic activity have put pressure on natural vegetation in the region, especially through
massive deforestation. Madagascar's high
endemism
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...
and species richness coupled with a sharp decrease in primary vegetation make the island a global
biodiversity hotspot
A biodiversity hotspot is a biogeographic region with significant levels of biodiversity that is threatened by human habitation. Norman Myers wrote about the concept in two articles in ''The Environmentalist'' in 1988 and 1990, after which the c ...
. To preserve natural habitats, around 10% of the land surface
is protected, including the
World Heritage
A World Heritage Site is a landmark or area with legal protection by an international convention administered by the United Nations Educational, Scientific and Cultural Organization (UNESCO). World Heritage Sites are designated by UNESCO for ...
sites
Tsingy de Bemaraha
Tsingy de Bemaraha Strict Nature Reserve is a nature reserve located near the western coast of Madagascar in Melaky Region at . The area was listed as a UNESCO World Heritage Site in 1990 due to the unique geography, preserved mangrove forests, ...
and the
Rainforests of the Atsinanana
The Rainforests of the Atsinanana is a World Heritage Site that was inscribed in 2007 and consists of 13 specific areas in six national parks in the eastern part of Madagascar:
# Marojejy National Park
# Masoala National Park
# Zahamena National ...
. While historically mainly European naturalists described Madagascar's flora scientifically, today a number of national and international herbaria, botanical gardens and universities document plant diversity and engage in its
conservation
Conservation is the preservation or efficient use of resources, or the conservation of various quantities under physical laws.
Conservation may also refer to:
Environment and natural resources
* Nature conservation, the protection and managem ...
.
Diversity and endemism
Madagascar has been described as "one of the most floristically unique places in the world".
, 343 families of
vascular
The blood vessels are the components of the circulatory system that transport blood throughout the human body. These vessels transport blood cells, nutrients, and oxygen to the tissues of the body. They also take waste and carbon dioxide away f ...
plants and
bryophytes, with roughly 12,000 species, were known according to the ''Catalogue of the plants of Madagascar''. Many plant groups are still insufficiently known.
Madagascar is the island with the second-highest number of vascular plants, behind
New Guinea
New Guinea (; Hiri Motu: ''Niu Gini''; id, Papua, or , historically ) is the world's second-largest island with an area of . Located in Oceania in the southwestern Pacific Ocean, the island is separated from Australia by the wide Torr ...
.
Of the vascular plants, 83% are
endemic
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...
: they are found only in Madagascar. These endemics include five entire plant families:
Asteropeiaceae
:''"Asteropeia" may also refer to a figure in Greek mythology, see Antinoe''
''Asteropeia'' is a genus of flowering plants. The genus contains 8 known species of shrubs and small trees, all endemic to Madagascar. It is the sole genus in family ...
,
Barbeuiaceae
''Barbeuia madagascariensis'' is a liana found only on the island of Madagascar.
''Barbeuia'' has occasionally been placed in its own family, Barbeuiaceae. The APG II system of 2003, for instance, recognizes such a family and assigns it to the ...
,
Physenaceae
''Physena'' is the sole genus of the flowering plant family Physenaceae. It contains two species of shrubs and small trees which are endemic to Madagascar. The APG II system, of 2003 (unchanged from the APG system, of 1998), does recognize this ...
,
Sarcolaenaceae and
Sphaerosepalaceae.
As many as 96% of Madagascan trees and shrubs are estimated to be endemic.
Vascular plants
![Angraecum sesquipedale cultivated](https://upload.wikimedia.org/wikipedia/commons/1/16/Angraecum_sesquipedale_cultivated.png)
Among the non-flowering plants,
fern
A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes exce ...
s,
lycophyte
The lycophytes, when broadly circumscribed, are a vascular plant (tracheophyte) subgroup of the kingdom Plantae. They are sometimes placed in a division Lycopodiophyta or Lycophyta or in a subdivision Lycopodiophytina. They are one of the oldes ...
s and allies count roughly 570 described species in Madagascar. About half of these are endemic; in the scaly tree fern family
Cyatheaceae
The Cyatheaceae are a family of ferns, the scaly tree ferns, one of eight families in the order Cyatheales in the Pteridophyte Phylogeny Group classification of 2016 (PPG I). Alternatively, the family may defined much more broadly (Cyatheaceae ...
, native to the humid forests, all but three of 47 species are endemic. Six
conifers in genus ''
Podocarpus
''Podocarpus'' () is a genus of conifers, the most numerous and widely distributed of the podocarp family, the Podocarpaceae. The name comes from Greek πούς (poús, “foot”) + καρπός (karpós, “fruit”). ''Podocarpus'' species ...
''all endemicand one
cycad
Cycads are seed plants that typically have a stout and woody (ligneous) trunk with a crown of large, hard, stiff, evergreen and (usually) pinnate leaves. The species are dioecious, that is, individual plants of a species are either male o ...
(''
Cycas thouarsii''), are native to the island.
In the
flowering plants
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...
,
basal groups and
magnoliids
Magnoliids (or Magnoliidae or Magnolianae) are a clade of flowering plants. With more than 10,000 species, including magnolias, nutmeg, bay laurel, cinnamon, avocado, black pepper, tulip tree and many others, it is the third-largest group of a ...
account for some 320 Madagascan species, around 94% of which are endemic. The families most rich in species are
Annonaceae
The Annonaceae are a family of flowering plants consisting of trees, shrubs, or rarely lianas commonly known as the custard apple family or soursop family. With 108 accepted genera and about 2400 known species, it is the largest family in the Ma ...
,
Lauraceae,
Monimiaceae
The Monimiaceae is a family of flowering plants in the magnoliid order Laurales.Peter F. Stevens (2001 onwards). "Monimiaceae" At: Angiosperm Phylogeny Website. At: Botanical Databases At: Missouri Botanical Garden Website. (see ''External links' ...
, and
Myristicaceae
The Myristicaceae are a Family (biology), family of flowering plants native to Africa, Asia, Pacific islands, and the Americas and has been recognized by most taxonomists. It is sometimes called the "nutmeg family", after its most famous member, ...
, containing mainly trees, shrubs, and
lianas, and the predominantly herbaceous pepper family (
Piperaceae
The Piperaceae (), also known as the pepper family, are a large family of flowering plants. The group contains roughly 3,600 currently accepted species in 5 genera. The vast majority of species can be found within the two main genera: ''Piper'' ...
).
Monocot
Monocotyledons (), commonly referred to as monocots, (Lilianae ''sensu'' Chase & Reveal) are grass and grass-like flowering plants (angiosperms), the seeds of which typically contain only one Embryo#Plant embryos, embryonic leaf, or cotyledon. Th ...
s are highly diversified. They include Madagascar's most species-rich plant family, the orchids (
Orchidaceae
Orchids are plants that belong to the family Orchidaceae (), a diverse and widespread group of flowering plants with blooms that are often colourful and fragrant.
Along with the Asteraceae, they are one of the two largest families of flowering ...
), with over 900 species of which 85% are endemic. Palms (
Arecaceae) have around 200 species in Madagascar (most in the large genus ''
Dypsis
''Dypsis'' is a genus of flowering plants in the family Arecaceae. They are slender, evergreen palms with yellow flowers carried in panicles amongst the pinnate leaves. Many ''Dypsis'' species have aerial branching (above the main trunk), a rare ...
''), more than three times as many as in continental Africa; all but five are endemic. Palm genera that are endemic to Madagascar are ''
Beccariophoenix'', ''
Bismarckia'', ''
Dypsis
''Dypsis'' is a genus of flowering plants in the family Arecaceae. They are slender, evergreen palms with yellow flowers carried in panicles amongst the pinnate leaves. Many ''Dypsis'' species have aerial branching (above the main trunk), a rare ...
'', ''
Lemurophoenix'', ''
Marojejya
''Marojejya'' is a genus of flowering plant in the family Arecaceae. It contains the following two species, both endemic to Madagascar
Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasik ...
'', ''
Masoala
''Masoala'' is a genus of flowering plant in the family Arecaceae. It contains the following species, both endemic to Madagascar
Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, ...
'', ''
Ravenea'', ''
Satranala
''Satranala decussilvae'' is a species of flowering plant in the Arecaceae family. It is a palm endemic to Madagascar. It is the only species in the genus ''Satranala'', and is threatened by habitat loss
Habitat destruction (also termed hab ...
'', ''
Tahina'', and ''
Voanioala''.
Other large monocot families include the
Pandanaceae with 88 endemic pandan (''
Pandanus'') species, mainly found in humid to wet habitats, and the
Asphodelaceae
Asphodelaceae is a family of flowering plants in the order Asparagales. Such a family has been recognized by most taxonomists, but the circumscription has varied widely. In its current circumscription in the APG IV system, it includes about 4 ...
, with most species and over 130 endemics in the succulent genus ''
Aloe''. Grasses (
Poaceae, around 550 species
) and sedges (
Cyperaceae, around 300) are species-rich, but have lower levels of endemism (40%
and 37%, respectively). The endemic traveller's tree (''
Ravenala madagascariensis''), a national emblem and widely planted, is the sole Madagascan species in the family
Strelitziaceae.
![Euphorbia iharanae ies](https://upload.wikimedia.org/wikipedia/commons/9/9b/Euphorbia_iharanae_ies.jpg)
The
eudicots
The eudicots, Eudicotidae, or eudicotyledons are a clade of flowering plants mainly characterized by having two seed leaves upon germination. The term derives from Dicotyledons.
Traditionally they were called tricolpates or non-magnoliid dicots ...
account for most of Madagascar's plant diversity. Their most species-rich families on the island are:
*
Fabaceae (legumes, 662 species – 77% endemic), accounting for many trees in humid and dry forests, including
rosewood
Rosewood refers to any of a number of richly hued timbers, often brownish with darker veining, but found in many different hues.
True rosewoods
All genuine rosewoods belong to the genus ''Dalbergia''. The pre-eminent rosewood appreciated ...
;
*
Rubiaceae
The Rubiaceae are a family of flowering plants, commonly known as the coffee, madder, or bedstraw family. It consists of terrestrial trees, shrubs, lianas, or herbs that are recognizable by simple, opposite leaves with interpetiolar stipules a ...
(coffee family, 632 – 92%), with notably over 100 endemic ''
Psychotria
''Psychotria'' is a genus of flowering plants in the Family (biology), family Rubiaceae. It contains 1,582 species and is therefore one of the largest genera of flowering plants. The genus has a pantropical distribution and members of the genus a ...
'' and 60 endemic ''
Coffea
''Coffea'' is a genus of flowering plants in the family Rubiaceae. ''Coffea'' species are shrubs or small trees native to tropical and southern Africa and tropical Asia. The seeds of some species, called coffee beans, are used to flavor vario ...
'' species;
*
Asteraceae
The family Asteraceae, alternatively Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae w ...
(composite family, 535 – 81%), with over 100 endemic species in ''
Helichrysum
The genus ''Helichrysum'' consists of an estimated 600 species of flowering plants in the sunflower family (Asteraceae). The type species is '' Helichrysum orientale''. They often go by the names everlasting, immortelle, and strawflower. The nam ...
'';
*
Acanthaceae
Acanthaceae is a family (the acanthus family) of dicotyledonous flowering plants containing almost 250 genera and about 2500 species. Most are tropical herbs, shrubs, or twining vines; some are epiphytes. Only a few species are distributed in tem ...
(acanthus family, 500 – 94%), with 90 endemic species in ''
Hypoestes'';
*
Euphorbiaceae
Euphorbiaceae, the spurge family, is a large family of flowering plants. In English, they are also commonly called euphorbias, which is also the name of a genus in the family. Most spurges, such as '' Euphorbia paralias'', are herbs, but some, ...
(spurge family, 459 – 94%), notably the large genera ''
Croton'' and ''
Euphorbia
''Euphorbia'' is a very large and diverse genus of flowering plants, commonly called spurge, in the family Euphorbiaceae. "Euphorbia" is sometimes used in ordinary English to collectively refer to all members of Euphorbiaceae (in deference to t ...
'';
*
Malvaceae
Malvaceae, or the mallows, is a family of flowering plants estimated to contain 244 genera with 4225 known species. Well-known members of economic importance include okra, cotton, cacao and durian. There are also some genera containing familiar ...
(mallows, 486 – 87%), including the large genus ''
Dombeya
''Dombeya'' is a flowering plant genus. Traditionally included in the family Sterculiaceae, it is included in the expanded Malvaceae in the APG and most subsequent systematics. These plants are known by a number of vernacular names which sometim ...
'' (17797%) and seven out of nine
baobabs (''Adansonia''), of which six are endemic;
*
Apocynaceae
Apocynaceae (from ''Apocynum'', Greek for "dog-away") is a family of flowering plants that includes trees, shrubs, herbs, stem succulents, and vines, commonly known as the dogbane family, because some taxa were used as dog poison Members of ...
(dogbane family, 363 – 93%), including the Madagascar periwinkle (''
Catharanthus roseus
''Catharanthus roseus'', commonly known as bright eyes, Cape periwinkle, graveyard plant, Madagascar periwinkle, old maid, pink periwinkle, rose periwinkle, is a species of flowering plant in the family Apocynaceae. It is native and endemic to M ...
'');
*
Melastomataceae
Melastomataceae is a family of dicotyledonous flowering plants found mostly in the tropics (two-thirds of the genera are from the New World tropics) comprising c. 175 genera and c. 5115 known species. Melastomes are annual or perennial herbs, s ...
(melastomes, 341 – 98%), mainly trees and shrubs.
Non-vascular plants
A checklist from 2012 records 751
moss species and
infraspecific taxa
In botany, an infraspecific name is the scientific name for any taxon below the rank of species, i.e. an infraspecific taxon or infraspecies. (A "taxon", plural "taxa", is a group of organisms to be given a particular name.) The scientific names ...
, 390
liverworts, and three
hornworts
Hornworts are a group of non-vascular Embryophytes (land plants) constituting the division Anthocerotophyta (). The common name refers to the elongated horn-like structure, which is the sporophyte. As in mosses and liverworts, hornworts have a g ...
. About 34% of the mosses and 19% of the liverworts are endemic. It is unknown how many of these species may have gone extinct since their discovery, and a number likely remain to be described.
Fungi
Many undescribed species of
fungi
A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from ...
are suspected in Madagascar.
A number of
edible mushrooms are consumed in the country, especially from the genera ''
Auricularia
''Auricularia'' is a genus of fungi in the family
Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maint ...
'', ''
Lepiota
''Lepiota'' is a genus of gilled mushrooms in the family Agaricaceae. All ''Lepiota'' species are ground-dwelling saprotrophs with a preference for rich, calcareous soils. Basidiocarps (fruit bodies) are agaricoid with whitish spores, typically ...
'', ''
Cantharellus
''Cantharellus'' is a genus of popular edible mushrooms, commonly known as chanterelles, a name which can also refer to the type species, '' Cantharellus cibarius''. They are mycorrhizal fungi, meaning they form symbiotic associations with plant ...
'' (the chanterelles), and ''
Russula
''Russula'' is a very large genus composed of around 750 worldwide species of ectomycorrhizal mushrooms. They are typically common, fairly large, and brightly colored – making them one of the most recognizable genera among mycologists and mushr ...
'' (the brittlegills).
Most of the
ectomycorrhizal species are found in plantations of introduced
eucalyptus
''Eucalyptus'' () is a genus of over seven hundred species of flowering trees, shrubs or mallees in the myrtle family, Myrtaceae. Along with several other genera in the tribe Eucalypteae, including '' Corymbia'', they are commonly known as e ...
and
pine
A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanical Garden accepts ...
, but also in native tapia (''
Uapaca bojeri
''Uapaca bojeri'', or tapia ( Malagasy pronunciation: ''ta-pee''), is a tree species endemic to Madagascar. A characteristic element of the Madagascan flora, it occurs in the central highlands, where it dominates a type of sclerophyllous fores ...
'') woodlands.
The chytrid fungus ''
Batrachochytrium dendrobatidis
''Batrachochytrium dendrobatidis'' ( ), also known as ''Bd'' or the amphibian chytrid fungus, is a fungus that causes the disease chytridiomycosis in amphibians.
Since its discovery in 1998 by Lee Berger, the disease devastated amphibian popula ...
'', responsible for
chytridiomycosis
Chytridiomycosis ( ) is an infectious disease in amphibians, caused by the chytrid fungi '' Batrachochytrium dendrobatidis'' and '' Batrachochytrium salamandrivorans''. Chytridiomycosis has been linked to dramatic population declines or extinc ...
, an infectious disease threatening amphibian populations worldwide, was long considered absent from Madagascar. In 2010 it was recorded, however, and has been confirmed since in various areas and in numerous frog families, alerting scientists to a new threat to the island's already endangered
frog fauna.
Over 500 species of
lichens of Madagascar have been documented, but the true number was estimated to be at least twice as high. Wet tropical areas of siliceous bedrock make up approximately two-thirds of the country, and are where most of the lichens have been found. Dry tropical areas of granitic and limestone bedrock make up the other one-third of the country with just over 20 species documented in these habitats.
Algae
Algae, a diverse group of non-plant
photosynthetic organisms, are in general poorly known in Madagascar. A review of freshwater
diatoms listed 134 species; most of them have been described from fossil deposits and it is unknown if they have become extinct. It is assumed that Madagascar harbours a rich endemic diatom flora. Diatom deposits from lake sediments have been used to reconstruct
paleoclimatic variations on the island.
Vegetation types
![Madagascar topo](https://upload.wikimedia.org/wikipedia/commons/e/e9/Madagascar_topo.jpg)
Madagascar features contrasting and unique
vegetation type
Vegetation classification is the process of classifying and mapping the vegetation over an area of the earth's surface. Vegetation classification is often performed by state based agencies as part of land use, resource and environmental manageme ...
s, determined mainly by topography, climate, and geology. A steep eastern
escarpment
An escarpment is a steep slope or long cliff that forms as a result of faulting or erosion and separates two relatively level areas having different elevations.
The terms ''scarp'' and ''scarp face'' are often used interchangeably with ''esca ...
captures most of the rainfall brought by
trade winds
The trade winds or easterlies are the permanent east-to-west prevailing winds that flow in the Earth's equatorial region. The trade winds blow mainly from the northeast in the Northern Hemisphere and from the southeast in the Southern Hemisp ...
from the Indian Ocean. Consequently, the eastern belt harbours most of the humid forests, while the west has a drier vegetation. The
rain shadow region in the southwest has a
sub-arid climate. The
central highlands, above , feature some high mountains, though the
Tsaratanana Massif
Madagascar is a large island in the Indian Ocean off the eastern coast of southern Africa, east of Mozambique. It has a total area of with of land and of water. Madagascar is the fourth largest island and the 2nd largest island country in th ...
in the north has the highest elevation, namely . Temperatures are highest on the west coast, with annual means of up to , while the high
massif
In geology, a massif ( or ) is a section of a planet's crust that is demarcated by faults or flexures. In the movement of the crust, a massif tends to retain its internal structure while being displaced as a whole. The term also refers to a ...
s have a cool climate with a annual mean. The
geology of Madagascar
The geology of Madagascar comprises a variety of rocks of Precambrian age which make up the larger part of the east and centre of the island. They are intruded by basalts and rhyolites of Mesozoic to Cenozoic age. In contrast, the western part of ...
features mainly
igneous
Igneous rock (derived from the Latin word ''ignis'' meaning fire), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rock is formed through the cooling and solidification of magma or ...
and
metamorphic
Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock (protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, causi ...
basement rocks, with some
lava
Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or un ...
and
quartzite
Quartzite is a hard, non- foliated metamorphic rock which was originally pure quartz sandstone.Essentials of Geology, 3rd Edition, Stephen Marshak, p 182 Sandstone is converted into quartzite through heating and pressure usually related to tec ...
in the central and eastern plateaus, while the western part has belts of
sandstone
Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks.
Most sandstone is composed of quartz or feldspar (both silicates ...
,
limestone
Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...
(including the
tsingy
Karst is a topography formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum. It is characterized by underground drainage systems with sinkholes and caves. It has also been documented for more weathering-resistan ...
formations), and unconsolidated sand.
The marked east–central–west distinction among Madagascan flora was already described by the English naturalist
Richard Baron in 1889.
Twentieth-century authors, including
Henri Perrier de la Bâthie and
Henri Humbert, built upon this concept and proposed several similar classification systems, based on