Myrtaceae, the myrtle family, is a family of dicotyledonous
plant
Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclud ...
pōhutukawa
''Metrosideros excelsa'', commonly known as pōhutukawa ( mi, pōhutukawa), New Zealand Christmas tree, New Zealand Christmas bush, and iron tree, is a coastal evergreen tree in the myrtle family, Myrtaceae, that produces a brilliant display o ...
clove
Cloves are the aromatic flower buds of a tree in the family Myrtaceae, ''Syzygium aromaticum'' (). They are native to the Maluku Islands (or Moluccas) in Indonesia, and are commonly used as a spice, flavoring or fragrance in consumer products, ...
,
guava
Guava () is a common tropical fruit cultivated in many tropical and subtropical regions. The common guava ''Psidium guajava'' (lemon guava, apple guava) is a small tree in the myrtle family ( Myrtaceae), native to Mexico, Central America, the ...
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 euca ...
are some notable members of this group. All species are woody, contain
essential oil
An essential oil is a concentrated hydrophobic liquid containing volatile (easily evaporated at normal temperatures) chemical compounds from plants. Essential oils are also known as volatile oils, ethereal oils, aetheroleum, or simply as the o ...
s, and have flower parts in multiples of four or five. The
leaves
A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...
are
evergreen
In botany, an evergreen is a plant which has foliage that remains green and functional through more than one growing season. This also pertains to plants that retain their foliage only in warm climates, and contrasts with deciduous plants, which ...
, alternate to mostly opposite, simple, and usually entire (i.e., without a toothed margin). The
flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechani ...
s have a base number of five petals, though in several genera, the petals are minute or absent. The
stamen
The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10
Morphology and terminology
A stamen typically consists of a stalk called the filame ...
s are usually very conspicuous, brightly coloured, and numerous.
Evolutionary history
Scientists hypothesize that the family Myrtaceae arose between 60 and 56 million years ago (Mya) during the
Paleocene
The Paleocene, ( ) or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), E ...
era. Pollen fossils have been sourced to the ancient supercontinent
Gondwana
Gondwana () was a large landmass, often referred to as a supercontinent, that formed during the late Neoproterozoic (about 550 million years ago) and began to break up during the Jurassic period (about 180 million years ago). The final stages ...
. The breakup of
Gondwana
Gondwana () was a large landmass, often referred to as a supercontinent, that formed during the late Neoproterozoic (about 550 million years ago) and began to break up during the Jurassic period (about 180 million years ago). The final stages ...
during the
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...
period (145 to 66 Mya) geographically isolated disjunct taxa and allowed for rapid speciation; in particular, genera once considered members of the now-defunct Leptospermoideae alliance are now isolated within
Oceania
Oceania (, , ) is a region, geographical region that includes Australasia, Melanesia, Micronesia, and Polynesia. Spanning the Eastern Hemisphere, Eastern and Western Hemisphere, Western hemispheres, Oceania is estimated to have a land area of ...
. Generally, experts agree that
vicariance
Allopatric speciation () – also referred to as geographic speciation, vicariant speciation, or its earlier name the dumbbell model – is a mode of speciation that occurs when biological populations become geographically isolated from ...
is responsible for the differentiation of Myrtaceae taxa, except in the cases of '' Leptospermum'' species now located on
New Zealand
New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
and
New Caledonia
)
, anthem = ""
, image_map = New Caledonia on the globe (small islands magnified) (Polynesia centered).svg
, map_alt = Location of New Caledonia
, map_caption = Location of New Caledonia
, mapsize = 290px
, subdivision_type = Sovereign st ...
, islands which may have been submerged at the time of late
Eocene
The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...
differentiation.
Diversity
Recent estimates suggest the Myrtaceae include about 5,950 species in about 132 genera. The family has a wide distribution in tropical and warm-temperate regions of the world, and is common in many of the world's
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 co ...
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 euca ...
Chile
Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...
and
Argentina
Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...
. Genera with fleshy fruits have their greatest concentrations in eastern
Australia
Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
and
Malesia
Malesia is a biogeographical region straddling the Equator and the boundaries of the Indomalayan and Australasian realms, and also a phytogeographical floristic region in the Paleotropical Kingdom. It has been given different definitions. The ...
(the
Australasian realm
The Australasian realm is a biogeographic realm that is coincident with, but not (by some definitions) the same as, the geographical region of Australasia. The realm includes Australia, the island of New Guinea (comprising Papua New Guinea and ...
) and the
Neotropic
The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropical terrestrial ecoregions of the Americas and the entire South American temperate zone.
Definition
In bioge ...
s. ''Eucalyptus'' is a dominant, nearly ubiquitous genus in the more mesic parts of Australia and extends north sporadically to the
Philippines
The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no),
* bik, Republika kan Filipinas
* ceb, Republika sa Pilipinas
* cbk, República de Filipinas
* hil, Republ ...
. ''
Eucalyptus regnans
''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 euc ...
'' is the tallest flowering plant in the world. Other important Australian genera are '' Callistemon'' (bottlebrushes), ''
Syzygium
''Syzygium'' () is a genus of flowering plants that belongs to the myrtle family, Myrtaceae. The genus comprises about 1200 species, and has a native range that extends from Africa and Madagascar through southern Asia east through the Pacific. ...
'', and '' Melaleuca'' (paperbarks). Species of the genus '' Osbornia'', native to Australasia, are
mangrove
A mangrove is a shrub or tree that grows in coastal saline water, 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 evoluti ...
s. ''
Eugenia
''Eugenia'' is a genus of flowering plants in the myrtle family Myrtaceae. It has a worldwide, although highly uneven, distribution in tropical and subtropical regions. The bulk of the approximately 1,100 species occur in the New World tropics, ...
'', '' Myrcia'', and '' Calyptranthes'' are among the larger genera in the neotropics.
Historically, the Myrtaceae were divided into two subfamilies. Subfamily Myrtoideae (about 75 genera) was recognized as having fleshy fruits and opposite, entire leaves. Most genera in this subfamily have one of three easily recognized types of embryos. The genera of Myrtoideae can be very difficult to distinguish in the absence of mature fruits. Myrtoideae are found worldwide in subtropical and tropical regions, with centers of diversity in the Neotropics, northeastern Australia, and Malesia. In contrast, subfamily Leptospermoideae (about 80 genera) was recognized as having dry, dehiscent fruits (capsules) and leaves arranged spirally or alternate. The Leptospermoideae are found mostly in Australasia, with a centre of diversity in Australia. Many genera in Western Australia have greatly reduced leaves and flowers typical of more xeric habitats.
Taxonomy
The division of the Myrtaceae into Leptospermoideae and Myrtoideae was challenged by a number of authors, including Johnson and Briggs (1984), who identified 14 tribes or clades within Myrtaceae, and found Myrtoideae to be polyphyletic. Molecular studies by several groups of authors, as of 2008, have confirmed the baccate (fleshy) fruits evolved twice from capsular fruits and, as such, the two-subfamily classification does not accurately portray the phylogenetic history of the family. Thus, many workers are now using a recent analysis by Wilson et al. (2001) as a starting point for further analyses of the family. This study pronounced both Leptospermoideae and Myrtoideae invalid, but retained several smaller suballiances shown to be monophyletic through matK analysis.
The genera '' Heteropyxis'' and ''
Psiloxylon
''Psiloxylon mauritianum'' (known locally as "bois bigaignon") is a species of flowering plant, the sole species of the genus ''Psiloxylon''. It is endemic to the Mascarene Islands (Mauritius and Réunion) in the Indian Ocean.
It is a white-ba ...
'' have been separated as separate families by many authors in the past as Heteropyxidaceae and Psiloxylaceae. However, Wilson ''et al.'' included them in Myrtaceae. These two genera are presently believed to be the earliest arising and surviving lineages of Myrtaceae.
The most recent classification recognizes 17 tribes and two subfamilies, Myrtoideae and Psiloxyloideae, based on a phylogenetic analysis of plastid DNA.
Many new species are being described annually from throughout the range of Myrtaceae. Likewise, new genera are being described nearly yearly.
Classification
Following Wilson (2011)
Subfamily
Psiloxyloideae
Myrtaceae, the myrtle family, is a family of dicotyledonous plants placed within the order Myrtales. Myrtle, pōhutukawa, bay rum tree, clove, guava, acca (feijoa), allspice, and eucalyptus are some notable members of this group. All species ...
* tribe
Psiloxyleae
''Psiloxylon mauritianum'' (known locally as "bois bigaignon") is a species of flowering plant, the sole species of the genus ''Psiloxylon''. It is endemic to the Mascarene Islands (Mauritius and Réunion) in the Indian Ocean.
It is a white-ba ...
Xanthostemoneae
Xanthostemoneae is a tribe in the plant family Myrtaceae.Wilson, P. G. (2011) Myrtaceae. In The Families and Genera of Vascular Plants. Volume X. Sapindales, Cucurbitales, Myrtaceae, edited by K. Kubitzki, X:212–71. Heidelberg: Springer-Verlag, ...
Syzygieae
''Syzygium'' () is a genus of flowering plants that belongs to the myrtle family, Myrtaceae. The genus comprises about 1200 species, and has a native range that extends from Africa and Madagascar through southern Asia east through the Pacific. I ...
Eucalypteae
Eucalypteae is a large tribe of flowering plants in the family Myrtaceae; members of this tribe are known as eucalypts. In Australia the genera ''Angophora'', ''Corymbia'', and ''Eucalyptus'' are commonly known as gum trees, for the sticky substa ...
Leptospermeae
Leptospermeae is a tribe in the plant family MyrtaceaeWilson, P. G. (2011) Myrtaceae. In The Families and Genera of Vascular Plants. Volume X. Sapindales, Cucurbitales, Myrtaceae, edited by K. Kubitzki, X:212–71. Heidelberg: Springer-Verlag, 20 ...
Agonis
''Agonis'' is a genus in the plant family Myrtaceae. All are endemic to Western Australia, growing near the coast in the south west.
Description
Only one, ''Agonis flexuosa'', grows to tree size; the others generally grow as tall shrubs.
'' ...
''
* ''
Algrizea
''Algrizea'' is a genus in the plant family Myrtaceae first described as a genus in 2006. The entire genus is endemic to the State of Bahia in northeastern Brazil.
;Species
# '' Algrizea macrochlamys'' (DC.) Proença & NicLugh. 2006. - Bahia
# ' ...
''
* ''
Allosyncarpia
''Allosyncarpia ternata'', commonly known as ''an-binik'', is a species of rainforest trees constituting part of the botanical family Myrtaceae and included in the eucalypts group. The only species in its genus, it was described in 1981 by St ...
''
* ''
Aluta
''Aluta'' is a genus of small shrubs in the family Myrtaceae. Species occur in Western Australia, South Australia and the Northern Territory. When the genus was erected in 2000, three species were transferred from the genus ''Thryptomene''.
Spe ...
''
* ''
Amomyrtella
''Amomyrtella'' is a genus of flowering plants in the myrtle family, Myrtaceae, first described as a genus in 1956. It is native to South America, where it is distributed from Ecuador to Argentina.Amomyrtus''
* '' Angasomyrtus''
* '' Angophora''
* '' Archirhodomyrtus''
* ''
Arillastrum
''Arillastrum'' is a monotypic genus of trees in the myrtle family, Myrtaceae, containing the single species ''Arillastrum gummiferum''. It is endemic to southern New Caledonia.Wilcox, M. (2004)''Le chêne gomme'' (''Arillastrum gummiferum'') & ...
''
* ''
Astartea
''Astartea'' is a genus of flowering plants in the myrtle family, Myrtaceae. The genus is endemic to southwestern Western Australia. The genus name was inspired by Astarte, the Greek name for the goddess Ishtar.Asteromyrtus
''Asteromyrtus'' is a genus of flowering plants in the Myrtaceae family. It is closely related to ''Callistemon'' and ''Melaleuca''.
History
''Asteromyrtus'' was described as a genus in 1843. The genus was subsequently subsumed into ''Melaleuca' ...
''
* ''
Astus
''Astus'' is a genus of flowering plants belonging to the family Myrtaceae.
Its native range is Southwest Australia.
Species:
*''Astus duomilia''
*''Astus subroseus''
*''Astus tetragonus''
*''Astus wittweri
''Astus'' is a genus of flowe ...
Babingtonia
''Babingtonia'' is a genus of flowering plants in the myrtle family, Myrtaceae. The species are native to Australia. Many species formerly placed in the genus are currently included in ''Sannantha'', '' Baeckea'', ''Oxymyrrhine'', ''Kardomia'' ...
''
* ''
Backhousia
''Backhousia'' is a genus of thirteen currently known species of flowering plants in the family Myrtaceae. All the currently known species are endemic to Australia in the rainforests and seasonally dry forests of Queensland, New South Wales and ...
Balaustion
''Balaustion'' is a monotypic genus of flowering plants in the myrtle family, Myrtaceae. The sole species is ''Balaustion pulcherrimum'', commonly known as the native pomegranate, which is endemic to Western Australia
Western Australia (commo ...
Basisperma
''Basisperma'' is a genus of flowering plants in the myrtle family, Myrtaceae first described as a genus in 1942. There is only one known species, ''Basisperma lanceolata'', endemic to Papua New Guinea
Papua New Guinea (abbreviated PNG; ...
Calothamnus
''Calothamnus'' is a genus of shrubs in the family Myrtaceae and is endemic to the south-west of Western Australia. The common names one-sided bottlebrush or claw flower are given to some species due to their having the flowers clustered on ...
Calytrix
''Calytrix'' is a genus of shrubs in the family Myrtaceae described as a genus in 1806. They are commonly known as starflowers. ''Calytrix'' are endemic to Australia, occurring in the (Northern Territory, Queensland, South Australia, and We ...
Cheyniana
''Cheyniana'' is a genus of flowering plants in the family Myrtaceae. Two species are currently recognised, both endemic to Western Australia:
*''Cheyniana microphylla'' (C.A.Gardner) Rye (basionym ''Balaustion microphyllum'') - Bush pomegranat ...
''
* ''
Choricarpia
''Backhousia'' is a genus of thirteen currently known species of flowering plants in the family Myrtaceae. All the currently known species are endemic to Australia in the rainforests and seasonally dry forests of Queensland, New South Wales a ...
Cloezia
''Cloezia'' is a genus (biology), genus of flowering plants in the family (biology), family Myrtaceae first described as a genus in 1863. The entire genus is endemic to New Caledonia. It is related to ''Thaleropia'', ''Tristania (plant), Tristan ...
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 euca ...
''
* ''
Eugenia
''Eugenia'' is a genus of flowering plants in the myrtle family Myrtaceae. It has a worldwide, although highly uneven, distribution in tropical and subtropical regions. The bulk of the approximately 1,100 species occur in the New World tropics, ...
Psiloxylon
''Psiloxylon mauritianum'' (known locally as "bois bigaignon") is a species of flowering plant, the sole species of the genus ''Psiloxylon''. It is endemic to the Mascarene Islands (Mauritius and Réunion) in the Indian Ocean.
It is a white-ba ...
Syzygium
''Syzygium'' () is a genus of flowering plants that belongs to the myrtle family, Myrtaceae. The genus comprises about 1200 species, and has a native range that extends from Africa and Madagascar through southern Asia east through the Pacific. ...
''Myrtaceae'' is foraged by many stingless bees, especially by species such as ''Melipona bicolor'' which gather pollen from this plant family. Some Australian species such as ''Tetragonula hockingsi'' And ''Tetragonula carbonaria'' are also known to collect resin from the mature seed pods of ''Corymbia torelliana'', resulting in ''Mellitochory'' as the seeds get stuck onto the ''corbiculae'' of the bees and sometimes be successfully disposed of by colony members that remove them. But usually, they are known to get stuck in the hives or near hive entrances instead in most cases hence also making it a minor nuisance for some keepers as they can take up a lot of space. Fortunately, this is only known to occur in the eastern areas of ''
Australia
Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
'', but could occur in other neighbouring countries where some '' Corymbia'' species are known to be native.
References
External links
*
{{Authority control
Myrtaceae,
Myrtales families