Malpighiales
Encyclopedia
Malpighiales is one of the largest orders
of flowering plant
s, containing about 16000 species
, approximately 7.8% of the eudicots
. The order is very diverse and hard to recognize except with molecular phylogenetic evidence. It is not part of any of the classification
systems that are based only on plant morphology
. Molecular clock
calculations estimate the origin of stem group Malpighiales at around 100 Mya (million years ago) and the origin of crown group
Malpighiales at about 90 Mya.
Malpighiales is divided into 32 to 42 families
, depending upon which clade
s in the order are given the taxonomic rank
of family. In the APG III system
, 35 families are recognized. Medusagynaceae, Quiinaceae, Peraceae, Malesherbiaceae, Turneraceae, Samydaceae, and Scyphostegiaceae are consolidated into other families. The largest family, by far, is Euphorbiaceae
, with about 6300 species in about 245 genera
.
In a 2009 study
of DNA sequence
s of 13 gene
s, 42 families were placed into 16 groups
, ranging in size from one to ten families. Almost nothing is known about the relationships among these 16 groups. Malpighiales and Lamiales
are the two large orders whose phylogeny remains mostly unresolved.
group called the COM clade, which consists of the orders Celastrales
, Oxalidales
, and Malpighiales. Some describe it as containing a fourth order, Huales, separating the family Huaceae
into its own order, separate from Oxalidales.
Some recent studies have placed Malpighiales as sister to Oxalidales sensu lato (including Huaceae), while others have found a different topology
for the COM clade.
The COM clade is part of an unranked
group known as Fabidae or eurosids I. The fabids, in turn, are part of a group that has long been recognized, namely, the rosids
.
in honor of Marcello Malpighi
's work on plants; Malpighia
is the type genus
for the Malpighiaceae
, a family of tropical and subtropical flowering plants.
The family Malpighiaceae
was the type family
for one of the orders created by Jussieu
in his 1789 work Genera Plantarum. Friedrich von Berchtold
and Jan Presl
described such an order in 1820. Unlike modern taxonomists, these authors did not use the suffix "ales" in naming their orders. The name "Malpighiales" is attributed by some to Carl von Martius
. In the twentieth century, it was usually associated with John Hutchinson
, who used it in all three editions of his book, The Families of Flowering Plants. The name was not used by those who wrote later, in the nineteen seventies, eighties, and nineties.
The first semblance of Malpighiales as we now know it came from a phylogeny of seed plants
published in 1993 and based upon DNA sequence
s of the gene rbcL
. This study recovered a group of rosids unlike any group found in any previous system of plant classification
. In order to make a clear break with classification
systems being used at that time, the Angiosperm Phylogeny Group
resurrected
Hutchinson's name, even though his concept of Malpighiales included much of what is now in Celastrales and Oxalidales.
was published in 2003, minor changes to the circumscription
of the order have been made. The family Peridiscaceae
has been expanded from two genera, to three, and then to four, and transferred to Saxifragales
.
The genera Cyrillopsis (Ixonanthaceae
), Centroplacus
(Centroplacaceae
), Bhesa
(Centroplacaceae), Aneulophus (Erythroxylaceae
), Ploiarium (Bonnetiaceae
), Trichostephanus (Samydaceae
), Sapria
(Rafflesiaceae
), Rhizanthes (Rafflesiaceae), and Rafflesia
(Rafflesiaceae) had been either added or confirmed as members of Malpighiales by the end of 2009.
Some family delimitation
s have changed as well, most notably, the segregation
of Calophyllaceae
from Clusiaceae
sensu lato when it was shown that the latter is paraphyletic. Some differences of opinion on family delimitation exist as well. For example, Samydaceae
and Scyphostegiaceae may be recognized as families or included in a large version of Salicaceae
.
level, an unresolved polytomy
of 16 clades. It has been estimated that complete resolution of the phylogeny will require at least 25000 base pair
s of DNA
sequence data per taxon
. A similar situation exists with Lamiales and it has been analyzed in some detail. The phylogenetic tree
shown below is from Wurdack and Davis (2009). The statistical support for each branch is 100% bootstrap
percentage and 100% posterior probability
, except where labeled, with bootstrap percentage followed by posterior probability.
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
of flowering plant
Flowering plant
The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...
s, containing about 16000 species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
, approximately 7.8% of the eudicots
Eudicots
Eudicots and Eudicotyledons are botanical terms introduced by Doyle & Hotton to refer to a monophyletic group of flowering plants that had been called tricolpates or non-Magnoliid dicots by previous authors...
. The order is very diverse and hard to recognize except with molecular phylogenetic evidence. It is not part of any of the classification
Systematics
Biological systematics is the study of the diversification of terrestrial life, both past and present, and the relationships among living things through time. Relationships are visualized as evolutionary trees...
systems that are based only on plant morphology
Plant morphology
Plant morphology or phytomorphology is the study of the physical form and external structure of plants. This is usually considered distinct from plant anatomy, which is the study of the internal structure of plants, especially at the microscopic level...
. Molecular clock
Molecular clock
The molecular clock is a technique in molecular evolution that uses fossil constraints and rates of molecular change to deduce the time in geologic history when two species or other taxa diverged. It is used to estimate the time of occurrence of events called speciation or radiation...
calculations estimate the origin of stem group Malpighiales at around 100 Mya (million years ago) and the origin of crown group
Crown group
A crown group is a group consisting of living representatives, their ancestors back to the most recent common ancestor of that group, and all of that ancestor's descendants. The name was given by Willi Hennig, the formulator of phylogenetic systematics, as a way of classifying living organisms...
Malpighiales at about 90 Mya.
Malpighiales is divided into 32 to 42 families
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
, depending upon which clade
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
s in the order are given the taxonomic rank
Taxonomic rank
In biological classification, rank is the level in a taxonomic hierarchy. Examples of taxonomic ranks are species, genus, family, and class. Each rank subsumes under it a number of less general categories...
of family. In the APG III system
APG III system
The APG III system of flowering plant classification is the third version of a modern, mostly molecular-based, system of plant taxonomy...
, 35 families are recognized. Medusagynaceae, Quiinaceae, Peraceae, Malesherbiaceae, Turneraceae, Samydaceae, and Scyphostegiaceae are consolidated into other families. The largest family, by far, is Euphorbiaceae
Euphorbiaceae
Euphorbiaceae, the Spurge family are a large family of flowering plants with 300 genera and around 7,500 species. Most are herbs, but some, especially in the tropics, are also shrubs or trees. Some are succulent and resemble cacti....
, with about 6300 species in about 245 genera
Genera
Genera is a commercial operating system and development environment for Lisp machines developed by Symbolics. It is essentially a fork of an earlier operating system originating on the MIT AI Lab's Lisp machines which Symbolics had used in common with LMI and Texas Instruments...
.
In a 2009 study
Research
Research can be defined as the scientific search for knowledge, or as any systematic investigation, to establish novel facts, solve new or existing problems, prove new ideas, or develop new theories, usually using a scientific method...
of DNA sequence
DNA sequence
The sequence or primary structure of a nucleic acid is the composition of atoms that make up the nucleic acid and the chemical bonds that bond those atoms. Because nucleic acids, such as DNA and RNA, are unbranched polymers, this specification is equivalent to specifying the sequence of...
s of 13 gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
s, 42 families were placed into 16 groups
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
, ranging in size from one to ten families. Almost nothing is known about the relationships among these 16 groups. Malpighiales and Lamiales
Lamiales
Lamiales is an order in the asterid group of dicotyledonous flowering plants. It includes approximately 11,000 species divided into about 20 families...
are the two large orders whose phylogeny remains mostly unresolved.
Affinities
Malpighiales is a member of a supraordinalTaxonomic rank
In biological classification, rank is the level in a taxonomic hierarchy. Examples of taxonomic ranks are species, genus, family, and class. Each rank subsumes under it a number of less general categories...
group called the COM clade, which consists of the orders Celastrales
Celastrales
Celastrales is an order of flowering plants. They are found throughout the tropics and subtropics, with only a few species extending far into the temperate regions. There are about 1200 to 1350 species in about 100 genera. All but 7 of these genera are in the large family Celastraceae...
, Oxalidales
Oxalidales
The Oxalidales are an order of flowering plants, included within the rosid subgroup of eudicots. The following families are typically placed here:* Family Brunelliaceae* Family Cephalotaceae * Family Connaraceae...
, and Malpighiales. Some describe it as containing a fourth order, Huales, separating the family Huaceae
Huaceae
Huaceae is a family of plant in the rosids group, which has been classed in the orders Malpighiales, Malvales, and Violales or in its own order Huales. The APG II system places it in the clade eurosids I, whereas the APG III system of 2009 placed it within the Oxalidales. It contains the following...
into its own order, separate from Oxalidales.
Some recent studies have placed Malpighiales as sister to Oxalidales sensu lato (including Huaceae), while others have found a different topology
Topology
Topology is a major area of mathematics concerned with properties that are preserved under continuous deformations of objects, such as deformations that involve stretching, but no tearing or gluing...
for the COM clade.
The COM clade is part of an unranked
Taxonomic rank
In biological classification, rank is the level in a taxonomic hierarchy. Examples of taxonomic ranks are species, genus, family, and class. Each rank subsumes under it a number of less general categories...
group known as Fabidae or eurosids I. The fabids, in turn, are part of a group that has long been recognized, namely, the rosids
Rosids
The rosids are members of a large clade of flowering plants, containing about 70,000 species, more than a quarter of all angiosperms. The clade is divided into 16 to 20 orders, depending upon circumscription and classification. These orders, in turn, together comprise about 140 families...
.
History
The great Swedish botanist Linnaeus named the genus MalpighiaMalpighia
Malpighia is a genus of flowering plants in the nance family, Malpighiaceae. It contains about 45 species of shrubs or small trees, all of which are native to the American tropics. The generic name honours Marcello Malpighi, a 17th century Italian physician and botanist. The species grow to tall,...
in honor of Marcello Malpighi
Marcello Malpighi
Marcello Malpighi was an Italian doctor, who gave his name to several physiological features, like the Malpighian tubule system.-Early years:...
's work on plants; Malpighia
Malpighia
Malpighia is a genus of flowering plants in the nance family, Malpighiaceae. It contains about 45 species of shrubs or small trees, all of which are native to the American tropics. The generic name honours Marcello Malpighi, a 17th century Italian physician and botanist. The species grow to tall,...
is the type genus
Type genus
In biological classification, a type genus is a representative genus, as with regard to a biological family. The term and concept is used much more often and much more formally in zoology than it is in botany, and the definition is dependent on the nomenclatural Code that applies:* In zoological...
for the Malpighiaceae
Malpighiaceae
Malpighiaceae is a family of flowering plants in the order Malpighiales. It comprises approximately 75 genera and 1300 species, all of which are native to the tropics and subtropics...
, a family of tropical and subtropical flowering plants.
The family Malpighiaceae
Malpighiaceae
Malpighiaceae is a family of flowering plants in the order Malpighiales. It comprises approximately 75 genera and 1300 species, all of which are native to the tropics and subtropics...
was the type family
Biological type
In biology, a type is one particular specimen of an organism to which the scientific name of that organism is formally attached...
for one of the orders created by Jussieu
Antoine Laurent de Jussieu
Antoine Laurent de Jussieu was a French botanist, notable as the first to propose a natural classification of flowering plants; much of his system remains in use today.-Life:...
in his 1789 work Genera Plantarum. Friedrich von Berchtold
Friedrich von Berchtold
Bedřich Karel Eugen Všemír Berchtold hrabě z Uherčic, , was a Czech physician and botanist.-Biography:Berchtold was born in Stráž nad Nežárkou , District Jindřichův Hradec, in the Czech Republic....
and Jan Presl
Jan Svatopluk Presl
Jan Svatopluk Presl was a Bohemian natural scientist.He was the brother of botanist Karel Bořivoj Presl . The Czech Botanical Society commemorated the two brothers by naming its principal publication Preslia...
described such an order in 1820. Unlike modern taxonomists, these authors did not use the suffix "ales" in naming their orders. The name "Malpighiales" is attributed by some to Carl von Martius
Carl Friedrich Philipp von Martius
Carl Friedrich Philipp von Martius was a German botanist and explorer.Martius was born at Erlangen, where he graduated M.D. in 1814, publishing as his thesis a critical catalogue of plants in the botanic garden of the university...
. In the twentieth century, it was usually associated with John Hutchinson
John Hutchinson (botanist)
John Hutchinson, OBE, FRS was a renowned English botanist, taxonomist and author.-Life and career:...
, who used it in all three editions of his book, The Families of Flowering Plants. The name was not used by those who wrote later, in the nineteen seventies, eighties, and nineties.
The first semblance of Malpighiales as we now know it came from a phylogeny of seed plants
Spermatophyte
The spermatophytes comprise those plants that produce seeds. They are a subset of the embryophytes or land plants...
published in 1993 and based upon DNA sequence
DNA sequence
The sequence or primary structure of a nucleic acid is the composition of atoms that make up the nucleic acid and the chemical bonds that bond those atoms. Because nucleic acids, such as DNA and RNA, are unbranched polymers, this specification is equivalent to specifying the sequence of...
s of the gene rbcL
RuBisCO
Ribulose-1,5-bisphosphate carboxylase oxygenase, commonly known by the shorter name RuBisCO, is an enzyme involved in the first major step of carbon fixation, a process by which atmospheric carbon dioxide is converted by plants to energy-rich molecules such as glucose. RuBisCo is an abbreviation...
. This study recovered a group of rosids unlike any group found in any previous system of plant classification
Biological classification
Biological classification, or scientific classification in biology, is a method to group and categorize organisms by biological type, such as genus or species. Biological classification is part of scientific taxonomy....
. In order to make a clear break with classification
Plant taxonomy
Plant taxonomy is the science that finds, describes, classifies, identifies, and names plants. It thus is one of the main branches of taxonomy.Plant taxonomy is closely allied to plant systematics, and there is no sharp boundary between the two...
systems being used at that time, the Angiosperm Phylogeny Group
Angiosperm Phylogeny Group
The Angiosperm Phylogeny Group, or APG, refers to an informal international group of systematic botanists who came together to try to establish a consensus on the taxonomy of flowering plants that would reflect new knowledge about plant relationships discovered through phylogenetic studies., three...
resurrected
Resurrection
Resurrection refers to the literal coming back to life of the biologically dead. It is used both with respect to particular individuals or the belief in a General Resurrection of the dead at the end of the world. The General Resurrection is featured prominently in Jewish, Christian, and Muslim...
Hutchinson's name, even though his concept of Malpighiales included much of what is now in Celastrales and Oxalidales.
Circumscription
Malpighiales is monophyletic and in molecular phylogenetic studies, it receives strong statistical support. Since the APG II systemAPG II system
The APG II system of plant classification is the second, now obsolete, version of a modern, mostly molecular-based, system of plant taxonomy that was published in April 2003 by the Angiosperm Phylogeny Group. It was a revision of the first APG system, published in 1998, and was superseded in 2009...
was published in 2003, minor changes to the circumscription
Circumscription (taxonomy)
In taxonomy, circumscription is the definition of the limits of a taxonomic group of organisms. One goal of taxonomy is to achieve a stable circumscription for every taxonomic group. Achieving stability can be simple or difficult....
of the order have been made. The family Peridiscaceae
Peridiscaceae
Peridiscaceae is a family of flowering plants in the order Saxifragales. It comprises four genera: Medusandra, Soyauxia, Peridiscus, and Whittonia. It has a disjunct distribution, with Peridiscus occurring in Venezuela and northern Brazil, Whittonia in Guyana, Medusandra in Cameroon, and Soyauxia...
has been expanded from two genera, to three, and then to four, and transferred to Saxifragales
Saxifragales
Saxifragales is an order of flowering plants. Their closest relatives are a large eudicot group known as the rosids by the definition of rosids given in the APG II classification system. Some authors define the rosids more widely, including Saxifragales as their most basal group. Saxifragales is...
.
The genera Cyrillopsis (Ixonanthaceae
Ixonanthaceae
Ixonanthaceae is a family of woody flowering plants up to 90 m tall , consisting of about 30 species in 4 or 5 genera....
), Centroplacus
Centroplacus
Centroplacus is a genus of the family Centroplacaceae. It was formerly classified in the Phyllanthaceae and given its own tribe, the Centroplaceae....
(Centroplacaceae
Centroplacaceae
Centroplacaceae is a family of flowering plants in the order Malpighiales and is recognized by the APG III system of classification. The family comprises two genera: Bhesa, which was formerly recognized in the Celastraceae, and Centroplacus, which was formerly recognized in the Euphorbiaceae...
), Bhesa
Bhesa
Bhesa is a genus of plant in family Centroplacaceae. A 2009 molecular phylogeny study places it in the family Centroplacaceae in the order Malpighiales.Species include:* Bhesa ceylanica, Ding Hou* Bhesa nitidissima, Kosterm....
(Centroplacaceae), Aneulophus (Erythroxylaceae
Erythroxylaceae
The Erythroxylaceae is a family of flowering plants consisting of 4 genera and approximately 240 species. The best-known species is the coca plant , the source of the drug cocaine....
), Ploiarium (Bonnetiaceae
Bonnetiaceae
Bonnetiaceae is a family of flowering plants, consisting of 3 genera and 35 species. The genus wholly belongs to the Neotropics, except the genus Ploiarium, which is also found in Malesia....
), Trichostephanus (Samydaceae
Samydaceae
Samydaceae is a family of tropical and subtropical woody plants, its best known genus being Casearia. It has always been of uncertain placement, in the past usually being submerged in the family Flacourtiaceae....
), Sapria
Sapria
Sapria is a genus of parasitic flowering plants. It grows within roots of Vitis and Tetrastigma. The genus is limited to the tropical forests of South and South-east Asia....
(Rafflesiaceae
Rafflesiaceae
Rafflesiaceae is a family of parasitic plants found in east and southeast Asia, including Rafflesia arnoldii, the plant with the largest flower of all plants. The plants are endoparasites of vines in the genus Tetrastigma and lack stems, leaves, roots, and any photosynthetic tissue...
), Rhizanthes (Rafflesiaceae), and Rafflesia
Rafflesia
Rafflesia is a genus of parasitic flowering plants. It contains approximately 28 species , all found in southeastern Asia, on the Malay Peninsula, Borneo, Sumatra, Thailand and the Philippines.Rafflesia was found in the Indonesian rain forest by an Indonesian guide working for Dr...
(Rafflesiaceae) had been either added or confirmed as members of Malpighiales by the end of 2009.
Some family delimitation
Circumscription (taxonomy)
In taxonomy, circumscription is the definition of the limits of a taxonomic group of organisms. One goal of taxonomy is to achieve a stable circumscription for every taxonomic group. Achieving stability can be simple or difficult....
s have changed as well, most notably, the segregation
Segregate (taxonomy)
In taxonomy, a segregate, or a segregate taxon is created when a taxon is split off, from another taxon. This other taxon will be better known, usually bigger, and will continue to exist, even after the segregate taxon has been split off...
of Calophyllaceae
Calophyllaceae
Calophyllaceae is a family of flowering plants in the order Malpighiales and is recognized by the APG III system of classification. Most of the genera included in this family were previously recognized in the tribe Calophylleae of the Clusiaceae family. The Angiosperm Phylogeny Group...
from Clusiaceae
Clusiaceae
The Clusiaceae or Guttiferae Juss. is a family of plants formerly including about 37 genera and 1610 species of trees and shrubs, often with milky sap and fruits or capsules for seeds. It is primarily tropical...
sensu lato when it was shown that the latter is paraphyletic. Some differences of opinion on family delimitation exist as well. For example, Samydaceae
Samydaceae
Samydaceae is a family of tropical and subtropical woody plants, its best known genus being Casearia. It has always been of uncertain placement, in the past usually being submerged in the family Flacourtiaceae....
and Scyphostegiaceae may be recognized as families or included in a large version of Salicaceae
Salicaceae
Salicaceae are a family of flowering plants. Recent genetic studies summarized by the Angiosperm Phylogeny Group has greatly expanded the circumscription of the family to contain 55 genera....
.
Phylogeny
As we know it in 2009, the phylogeny of Malpighiales is, at its deepestBasal (phylogenetics)
In phylogenetics, a basal clade is the earliest clade to branch in a larger clade; it appears at the base of a cladogram.A basal group forms an outgroup to the rest of the clade, such as in the following example:...
level, an unresolved polytomy
Polytomy
A polytomy , meaning many temporal based branches, is a section of a phylogeny in which the evolutionary relationships can not be fully resolved to dichotomies. In a phylogenetic tree, a polytomy is represented as a node which has more than two immediate descending branches...
of 16 clades. It has been estimated that complete resolution of the phylogeny will require at least 25000 base pair
Base pair
In molecular biology and genetics, the linking between two nitrogenous bases on opposite complementary DNA or certain types of RNA strands that are connected via hydrogen bonds is called a base pair...
s of DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
sequence data per taxon
Taxon
|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...
. A similar situation exists with Lamiales and it has been analyzed in some detail. The phylogenetic tree
Phylogenetic tree
A phylogenetic tree or evolutionary tree is a branching diagram or "tree" showing the inferred evolutionary relationships among various biological species or other entities based upon similarities and differences in their physical and/or genetic characteristics...
shown below is from Wurdack and Davis (2009). The statistical support for each branch is 100% bootstrap
Bootstrapping (statistics)
In statistics, bootstrapping is a computer-based method for assigning measures of accuracy to sample estimates . This technique allows estimation of the sample distribution of almost any statistic using only very simple methods...
percentage and 100% posterior probability
Posterior probability
In Bayesian statistics, the posterior probability of a random event or an uncertain proposition is the conditional probability that is assigned after the relevant evidence is taken into account...
, except where labeled, with bootstrap percentage followed by posterior probability.