''Avicennia'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

flowering plant 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 ...

s currently placed in the bear's breeches family,

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 ...

. It contains

mangrove 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 ...

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...

s, which occur in the intertidal zones of estuarine areas and are characterized by its "pencil roots", which are

aerial roots Aerial roots are roots above the ground. They are almost always adventitious. They are found in diverse plant species, including epiphytes such as orchids (''Orchidaceae''), tropical coastal swamp trees such as mangroves, banyan figs (''Fic ...

. They are also commonly known as ''api api'', which in the

Malay language Malay (; ms, Bahasa Melayu, links=no, Jawi alphabet, Jawi: , Rejang script, Rencong: ) is an Austronesian languages, Austronesian language that is an official language of Brunei, Indonesia, Malaysia, and Singapore, and that is also spo ...

means "fires", a reference to the fact that

fireflies The Lampyridae are a family of elateroid beetles with more than 2,000 described species, many of which are light-emitting. They are soft-bodied beetles commonly called fireflies, lightning bugs, or glowworms for their conspicuous production ...

often congregate on these trees. Species of ''Avicennia'' occur worldwide south of the

Tropic of Cancer The Tropic of Cancer, which is also referred to as the Northern Tropic, is the most northerly circle of latitude on Earth at which the Sun can be directly overhead. This occurs on the June solstice, when the Northern Hemisphere is tilted tow ...

. The taxonomic placement of ''Avicennia'' is contentious. In some classifications, it has been placed in the family

Verbenaceae The Verbenaceae ( ), the verbena family or vervain family, is a family of mainly tropical flowering plants. It contains trees, shrubs, and herbs notable for heads, spikes, or clusters of small flowers, many of which have an aromatic smell. The ...

, but more recently has been placed by some botanists in the monogeneric family Avicenniaceae. Recent

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

studies have suggested that ''Avicennia'' is derived from within

, and the genus is included in that family in the

Angiosperm Phylogeny Group The Angiosperm Phylogeny Group (APG) is an informal international group of systematic botanists who collaborate to establish a consensus on the taxonomy of flowering plants (angiosperms) that reflects new knowledge about plant relationships disc ...

system. Designation of species is made difficult by the great variations in form of ''

Avicennia marina ''Avicennia marina'', commonly known as grey mangrove or white mangrove, is a species of mangrove tree classified in the plant family Acanthaceae (formerly in the Verbenaceae or Avicenniaceae). As with other mangroves, it occurs in the interti ...

''. Between eight and 10 species are usually recognised, with ''A. marina'' further divided into a number of subspecies. The generic name honours

Persian Persian may refer to: * People and things from Iran, historically called ''Persia'' in the English language ** Persians, the majority ethnic group in Iran, not to be conflated with the Iranic peoples ** Persian language, an Iranian language of the ...

physician A physician (American English), medical practitioner (Commonwealth English), medical doctor, or simply doctor, is a health professional who practices medicine, which is concerned with promoting, maintaining or restoring health through th ...

Avicenna (980-1037).

Description

Members of the genus are among the most salt-tolerant mangroves and are often the first to colonise new deposits of sediment. The sap is salty, and excess salt is secreted through the leaves. The spreading root system provides stability in shifting substrates. Vertical roots called

pneumatophore Aerial roots are roots above the ground. They are almost always adventitious. They are found in diverse plant species, including epiphytes such as orchids (''Orchidaceae''), tropical coastal swamp trees such as mangroves, banyan figs (''Fic ...

s project from the mud, thus the term "pencil roots". These are used in gas exchange as very little oxygen is available in the mud. The flowers are fragrant and rich in nectar, and are pollinated by insects. The embryos exhibit cryptovivipary, a process where they start to develop before the seed is shed, but do not break through the outside of the fruit capsule.

List of species

* ''

Avicennia alba ''Avicennia alba'' is a species of tropical mangrove in the family Acanthaceae. It is found growing in coastal and estuarine locations in India, Southeast Asia, Australia, and Oceania. Description ''A. alba'' forms a low, dense bushy crown ofte ...

'' Blume * ''

Avicennia balanophora ''Avicennia'' is a genus of flowering plants currently placed in the bear's breeches family, Acanthaceae. It contains mangrove trees, which occur in the intertidal zones of estuarine areas and are characterized by its "pencil roots", which are ...

'' Stapf & Moldenke * ''

Avicennia bicolor ''Avicennia'' is a genus of flowering plants currently placed in the bear's breeches family, Acanthaceae. It contains mangrove trees, which occur in the intertidal zones of estuarine areas and are characterized by its "pencil roots", which are ...

'' Standl. * ''

Avicennia germinans ''Avicennia germinans'', the black mangrove, is a shrub or small tree growing up to 12 meters (39 feet) in the acanthus family, Acanthaceae. It grows in tropical and subtropical regions of the Americas, on both the Atlantic and Pacific Coasts, ...

'' (L.) L. * ''

Avicennia integra ''Avicennia'' is a genus of flowering plants currently placed in the bear's breeches family, Acanthaceae. It contains mangrove trees, which occur in the intertidal zones of estuarine areas and are characterized by its "pencil roots", which are ...

'' N.C.Duke * ''

'' (Forssk.) Vierh. ** ''A. m.'' subsp. ''australasica'' (Walp.) J.Everett ** ''A. m.'' subsp. ''eucalyptifolia'' (Valeton) J.Everett ** ''A. m.'' subsp. ''marina'' ** ''A. m.'' var. ''rumphiana'' (Hallier f.) Bakh. * ''

Avicennia officinalis ''Avicennia officinalis'' is a species of mangrove also known as Indian mangrove. It is named after the famous Persian scientist Ibn Sina. The young tree forms a low, dense bushy crown. When it matures, it forms a columnar tree up to 15 m and ...

'' L. * ''

Avicennia schaueriana ''Avicennia'' is a genus of flowering plants currently placed in the bear's breeches family, Acanthaceae. It contains mangrove trees, which occur in the intertidal zones of estuarine areas and are characterized by its "pencil roots", which are ...

'' Stapf & Leechm. ex Moldenke * '' Avicennia tonduzii'' Moldenke

References

External links

* *
''Avicennia''
i

* {{Taxonbar, from=Q132645 Acanthaceae genera Taxa named by Carl Linnaeus Taxa named by Peter Forsskål Avicenna

Description

List of species

References

Further reading

External links