23-540: About 130; see list Myrtaceae ( / m ə r ˈ t eɪ s i ˌ aɪ , - s iː ˌ iː / ), 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 are woody, contain essential oils , and have flower parts in multiples of four or five. The leaves are evergreen , alternate to mostly opposite, simple, and usually entire (i.e., without
46-621: A single sulcus. Contrastingly, eudicots have tricolpate pollen (or derived forms): grains with three or more pores set in furrows called colpi. Aside from cotyledon number, other broad differences have been noted between monocots and dicots, although these have proven to be differences primarily between monocots and eudicots . Many early-diverging dicot groups have monocot characteristics such as scattered vascular bundles , trimerous flowers, and non-tricolpate pollen . In addition, some monocots have dicot characteristics such as reticulated leaf veins . The consensus phylogenetic tree used in
69-494: A toothed margin). The flowers have a base number of five petals, though in several genera, the petals are minute or absent. The stamens are usually very conspicuous, brightly coloured, and numerous. Scientists hypothesize that the family Myrtaceae arose between 60 and 56 million years ago (Mya) during the Paleocene era. Pollen fossils have been sourced to the ancient supercontinent Gondwana . The breakup of Gondwana during
92-609: The APG IV system shows that the group traditionally treated as the dicots is paraphyletic to the monocots: Amborellales Nymphaeales Austrobaileyales Chloranthales magnoliids Ceratophyllales eudicots monocots Traditionally, the dicots have been called the Dicotyledones (or Dicotyledoneae ), at any rank. If treated as a class, as they are within the Cronquist system , they could be called
115-589: The Cretaceous 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 . Generally, experts agree that vicariance is responsible for the differentiation of Myrtaceae taxa, except in the cases of Leptospermum species now located on New Zealand and New Caledonia , islands which may have been submerged at
138-699: The Americas, apart from Metrosideros in Chile and Argentina . Genera with fleshy fruits have their greatest concentrations in eastern Australia and Malesia (the Australasian realm ) and the Neotropics . Eucalyptus is a dominant, nearly ubiquitous genus in the more mesic parts of Australia and extends north sporadically to the Philippines . Eucalyptus regnans is the tallest flowering plant in
161-622: The Magnoliopsida after the type genus Magnolia . In some schemes, the eudicots were either treated as a separate class , the Rosopsida (type genus Rosa ), or as several separate classes. The remaining dicots ( palaeodicots or basal angiosperms) may be kept in a single paraphyletic class, called Magnoliopsida , or further divided. Some botanists prefer to retain the dicotyledons as a valid class, arguing its practicality and that it makes evolutionary sense. The following lists show
184-574: 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 have been separated as separate families by many authors in
207-417: The eastern areas of Australia , but could occur in other neighbouring countries where some Corymbia species are native. Weevils in the tribe Cryptoplini mostly use Myrtaceae as hosts. Their larvae can develop in flower and fruit buds, or in galls (often galls already formed by other insects). Dicotyledon The dicotyledons , also known as dicots (or, more rarely, dicotyls ), are one of
230-422: The mature seed pods of Corymbia torelliana , resulting in mellitochory as the seeds get stuck onto the corbiculae of the bees and sometimes are successfully disposed of by colony members that remove them. But usually, they get stuck in the hives or near hive entrances instead, 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
253-425: The monocots did; in other words, monocots evolved from within the dicots, as traditionally defined. The traditional dicots are thus a paraphyletic group. The eudicots are the largest monophyletic group within the dicotyledons. They are distinguished from all other flowering plants by the structure of their pollen . Other dicotyledons and the monocotyledons have monosulcate pollen (or derived forms): grains with
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#1732776176831276-633: The orders in the Angiosperm Phylogeny Group APG IV system traditionally called dicots, together with the older Cronquist system . Under the Dahlgren and Thorne systems, the subclass name Magnoliidae was used for the dicotyledons. This is also the case in some of the systems derived from the Cronquist system. These two systems are contrasted in the table below in terms of how each categorises by superorder; note that
299-482: 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
322-459: The range of Myrtaceae. Likewise, new genera are being described nearly yearly. Following Wilson (2011) Subfamily Psiloxyloideae Subfamily Myrtoideae 127 genera are currently accepted: 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 T. carbonaria are also known to collect resin from
345-405: The sequence within each system has been altered in order to pair corresponding taxa The Thorne system (1992) as depicted by Reveal is: Ranunculanae Rafflesianae Plumbaginanae Polygonanae Primulanae Ericanae Celastranae Geranianae Vitanae Aralianae Lamianae There exist variances between the superorders circumscribed from each system. Namely, although
368-451: The systems share common names for many of the listed superorders, the specific list orders classified within each varies. For example, Thorne's Theanae corresponds to five distinct superorders under Dahlgren's system, only one of which is called Theanae. Heteropyxis Heteropyxis canescens Heteropyxis dehniae Heteropyxis natalensis Heteropyxis is a genus which includes three species of small evergreen trees . It
391-417: The time of late Eocene differentiation. 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 hotspots . Genera with capsular fruits such as Eucalyptus , Corymbia , Angophora , Leptospermum , and Melaleuca are absent from
414-423: The two divisions of the flowering plants. Largely from the 1990s onwards, molecular phylogenetic research confirmed what had already been suspected: that dicotyledons are not a group made up of all the descendants of a common ancestor (i.e., they are not a monophyletic group). Rather, a number of lineages, such as the magnoliids and groups now collectively known as the basal angiosperms , diverged earlier than
437-438: The two groups into which all the flowering plants (angiosperms) were formerly divided. The name refers to one of the typical characteristics of the group: namely, that the seed has two embryonic leaves or cotyledons . There are around 200,000 species within this group. The other group of flowering plants were called monocotyledons (or monocots), typically each having one cotyledon. Historically, these two groups formed
460-400: The world. Other important Australian genera are Callistemon (bottlebrushes), Syzygium , and Melaleuca (paperbarks). Species of the genus Osbornia , native to Australasia, are mangroves . Eugenia , Myrcia , and Calyptranthes are among the larger genera in the neotropics. Historically, the Myrtaceae were divided into two subfamilies. Subfamily Myrtoideae (about 75 genera)
483-796: Was previously placed alone in family Heteropyxidaceae , but is now placed basally within Myrtaceae . The species of Heteropyxis are native to southern Africa . Heteropyxis natalensis , commonly known as lavender tree or laventelboom , ranges from Zimbabwe through Limpopo , Mpumalanga and KwaZulu-Natal of South Africa . It is a slender, upright tree which grows 5–7 metres in height, at forest margins, rocky outcrops, hillsides, and termite mounds. It bears panicles of fragrant flowers , cream to pale yellow in colour, from December to March. Many classification schemes place Heteropyxis within family Myrtaceae . Recent embryological and DNA analyses seem to indicate that Heteropyxis and Psiloxylon ,
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#1732776176831506-799: 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. 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
529-513: 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)
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