''Avicennia'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...

s currently placed in the bear's breeches family,

Acanthaceae Acanthaceae () is a Family (biology), family (the acanthus family) of dicotyledonous flowering plants containing almost 250 genera and about 2500 species. Most are Tropics, tropical Herbaceous plant, herbs, shrubs, or twining vines; some are epip ...

. It contains

mangrove A mangrove is a shrub or tree that grows mainly in coastal saline water, saline or brackish water. Mangroves grow in an equatorial climate, typically along coastlines and tidal rivers. They have particular adaptations to take in extra oxygen a ...

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, e.g., including only woody plants with secondary growth, only ...

s, which occur in the

intertidal zone The intertidal zone or foreshore is the area above water level at low tide and underwater at high tide; in other words, it is the part of the littoral zone within the tidal range. This area can include several types of habitats with various ...

s of

estuarine An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environm ...

areas and are characterized by its "pencil roots", which are

aerial roots Aerial roots are roots growing above the ground. They are often adventitious, i.e. formed from nonroot tissue. They are found in diverse plant species, including epiphytes such as orchids (''Orchidaceae''), tropical coastal swamp trees such ...

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

Malay language Malay ( , ; , Jawi alphabet, Jawi: ) is an Austronesian languages, Austronesian language spoken primarily by Malays (ethnic group), Malays in several islands of Maritime Southeast Asia and the Malay Peninsula on the mainland Asia. The lang ...

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, also known as the Northern Tropic, is the Earth's northernmost circle of latitude where the Sun can be seen directly overhead. This occurs on the June solstice, when the Northern Hemisphere is tilted toward the Sun ...

. 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. T ...

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

phylogenetic In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...

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 intert ...

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

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

. 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, medical practitioner (British English), medical doctor, or simply doctor is a health professional who practices medicine, which is concerned with promoting, maintaining or restoring health through the Medical education, study, Med ...

Avicenna Ibn Sina ( – 22 June 1037), commonly known in the West as Avicenna ( ), was a preeminent philosopher and physician of the Muslim world, flourishing during the Islamic Golden Age, serving in the courts of various Iranian peoples, Iranian ...

(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 growing above the ground. They are often adventitious, i.e. formed from nonroot tissue. They are found in diverse plant species, including epiphytes such as orchids (''Orchidaceae''), tropical coastal swamp trees such ...

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 Nectar is a viscous, sugar-rich liquid produced by Plant, plants in glands called nectaries, either within the flowers with which it attracts pollination, pollinating animals, or by extrafloral nectaries, which provide a nutrient source to an ...

, 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

Eight species are currently accepted:''Avicennia'' L.
''

Plants of the World Online Plants of the World Online (POWO) is an online taxonomic database published by the Royal Botanic Gardens, Kew. History Following the Convention on Biological Diversity, the Royal Botanic Gardens in Kew launched Plants of the World Online i ...

'', Kew Science. Accessed 21 August 2024. Avicennia propagule

* ''

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 often ...

'' Blume * ''

Avicennia balanophora ''Avicennia balanaphora'' is a species of tropical mangrove in the family Acanthaceae. It is endemic to Queensland, Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland ...

'' Stapf & Moldenke * ''

Avicennia bicolor ''Avicennia bicolor'' is a species of tropical mangrove in the family Acanthaceae. It grows in coastal and estuarine locations in the Tropical Eastern Pacific, from southern Mexico (Chiapas) along the Pacific coast of Central America to western C ...

'' 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 integra'' is a species of tropical mangrove in the family Acanthaceae. It grows in coastal and estuarine locations in the Northern Territory, Australia.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 intert ...

'' (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. (syn ''Avicennia lanata'' and ''Avicennia rumphiana'' * ''

Avicennia officinalis ''Avicennia officinalis'' is a species of mangrove also known as Indian mangrove. The genus ''Avicennia'' is named after the famous Persian scientist Ibn Sina. Description The young tree forms a low, dense bushy crown. When it matures, it forms ...

'' L. * ''

Avicennia schaueriana ''Avicennia schaueriana'' is a species of tropical mangrove in the Family (biology), family Acanthaceae. It grows in coastal and estuarine locations along the Atlantic coast of northeastern South America, from Venezuela and the Leeward Islands th ...

'' Stapf & Leechm. ex Moldenke

References

External links

* *
''Avicennia''
i

* {{Taxonbar, from=Q132645 Acanthaceae genera Avicenna Mangroves Taxa described in 1753 Taxa named by Carl Linnaeus

Description

List of species

References

Further reading

External links