Ranunculales is an

order Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ideas and objects are recognized, differentiated, and understood ...

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. Of necessity it contains the family

Ranunculaceae Ranunculaceae (, buttercup or crowfoot family; Latin "little frog", from "frog") is a family (biology), family of over 2,000 known species of flowering plants in 43 genera, distributed worldwide. The largest genera are ''Ranunculus'' (600 spec ...

, the buttercup family, because the name of the order is based on the name of a genus in that family. Ranunculales belongs to a

paraphyletic group Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In con ...

known as the basal eudicots. It is the most basal clade in this group; in other words, it is

sister A sister is a woman or a girl who shares parents or a parent with another individual; a female sibling. The male counterpart is a brother. Although the term typically refers to a familial relationship, it is sometimes used endearingly to ref ...

to the remaining eudicots. Widely known members include poppies, barberries,

hellebore Commonly known as hellebores (), the Eurasian genus ''Helleborus'' consists of approximately 20 species of herbaceous or evergreen perennial plant, perennial flowering plants in the family (biology), family Ranunculaceae, within which it gave i ...

s, and buttercups.

Taxonomy

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 ...

recognized seven families in Ranunculales in their

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 being developed by the Angiosperm Phylogeny Group (APG). Published in 2009, it was superseded in 2016 by a f ...

published Publishing is the activities of making information, literature, music, software, and other content, physical or digital, available to the public for sale or free of charge. Traditionally, the term publishing refers to the creation and distribu ...

in 2009. In the preceding

APG II system The APG II system (Angiosperm Phylogeny Group II system) of plant classification is the second, now obsolete, version of a modern, mostly Molecular phylogenetics, molecular-based, list of systems of plant taxonomy, system of plant taxonomy that ...

, they offered the option of three segregate families as shown below. * order Ranunculales *: family

Berberidaceae The Berberidaceae are a family (biology), family of 18 genera of flowering plants commonly called the barberry family. This family is in the order (biology), order Ranunculales. The family contains about 700 known species, of which the majority ...

*: family Circaeasteraceae *:: family Kingdoniaceae ">Kingdoniaceae.html" ;"title=" family Kingdoniaceae"> family Kingdoniaceae *: family Eupteleaceae *: family

Lardizabalaceae Lardizabalaceae is a family (biology), family of flowering plants. The family has been universally recognized by taxonomists, including the APG II system (2003; unchanged from the APG system of 1998), which places it in the order Ranunculales, ...

*: family

Menispermaceae Menispermaceae (botanical Latin: 'moonseed family' from Greek ''mene'' 'crescent moon' and ''sperma'' 'seed') is a family (biology), family of flowering plants. The alkaloid tubocurarine, a neuromuscular blocker and the active ingredient in the ...

*: family Papaveraceae *:: [+ family Fumariaceae ] *:: [+ family Pteridophyllaceae ] *: family

Note: "+ ..." = optionally separate family (that may be split off from the preceding family). Under this definition, well-known members of Ranunculales include

buttercup ''Ranunculus'' is a large genus of about 1750 species of flowering plants in the family Ranunculaceae. Members of the genus are known as buttercups, spearworts and water crowfoots. The genus is distributed worldwide, primarily in temperate an ...

clematis ''Clematis'' is a genus of about 380 species within the buttercup family, Ranunculaceae. Their garden hybrids and cultivars have been popular among gardeners, beginning with ''Clematis'' 'Jackmanii', a garden staple since 1862; more cultivars ...

, columbines,

delphinium ''Delphinium'' is a genus of about 300 species of annual and perennial flowering plants in the family (biology), family Ranunculaceae, native species, native throughout the Northern Hemisphere and also on the high mountains of tropical Africa. T ...

s, and poppies. A

phylogeny A phylogenetic tree or phylogeny is a graphical representation which shows the evolutionary history between a set of species or Taxon, taxa during a specific time.Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, M ...

of Ranunculales was published in 2009, based on

molecular phylogenetic Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

analysis of

DNA sequence A nucleic acid sequence is a succession of bases within the nucleotides forming alleles within a DNA (using GACT) or RNA (GACU) molecule. This succession is denoted by a series of a set of five different letters that indicate the order of the nu ...

s. The authors of this

paper Paper is a thin sheet material produced by mechanically or chemically processing cellulose fibres derived from wood, Textile, rags, poaceae, grasses, Feces#Other uses, herbivore dung, or other vegetable sources in water. Once the water is dra ...

revised the subfamilies and

tribes The term tribe is used in many different contexts to refer to a category of human social group. The predominant worldwide use of the term in English is in the discipline of anthropology. The definition is contested, in part due to conflict ...

of the order. This is reflected in the subsequent revision of the APG, APG IV (2016). The analysis revealed that the order consisted of three

clades In biology, a clade (), also known as a monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach to taxonomy ...

, Eupteleaceae, Papaveraceae and a third clade, considered to be the "core" Ranuculales, consisting of the remaining five families. The phylogeny of the families is shown in the cladogram.

Evolution

The fossil form ''

Leefructus ''Leefructus'' is an extinct genus of eudicot plants which existed in Yixian Formation, China during the early Cretaceous period. It was first named by Ge Sun, David L. Dilcher, Hongshan Wang and Zhiduan Chen in 2011 and the type species I ...

'', described in 2011, has been recognized as a member of this order. ''Leefructus mirus'' shows fully developed leaves; stem and flower that are very similar in structure to those of the modern buttercups. The fossil is dated to 125 Mya ( million years old) and it not only proves that Ranunculales is an ancient group of

eudicots The eudicots or eudicotyledons are flowering plants that have two seed leaves (cotyledons) upon germination. The term derives from ''dicotyledon'' (etymologically, ''eu'' = true; ''di'' = two; ''cotyledon'' = seed leaf). Historically, authors h ...

but demonstrates that the whole

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

clade may be older than expected. The structure of the plant and its age may lead to a new approach regarding the field that studies the evolution of

s. The fact that ''Leefructus'' shows a well-developed structure similar to modern ranunculids suggests that this group of eudicots may have developed earlier than the age of the fossil. Another fossil has been described with the name '' Teixeiraea'', also from the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

Portugal Portugal, officially the Portuguese Republic, is a country on the Iberian Peninsula in Southwestern Europe. Featuring Cabo da Roca, the westernmost point in continental Europe, Portugal borders Spain to its north and east, with which it share ...

. The genus '' Atli'' from the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...

of Canada appears to have had a

liana A liana is a long-Plant stem, stemmed Woody plant, woody vine that is rooted in the soil at ground level and uses trees, as well as other means of vertical support, to climb up to the Canopy (biology), canopy in search of direct sunlight. T ...

-like growth habit. According to

molecular clock The molecular clock is a figurative term for a technique that uses the mutation rate of biomolecules to deduce the time in prehistory when two or more life forms diverged. The biomolecular data used for such calculations are usually nucleot ...

calculations, the lineage that led to Ranunculales split from other plants about 132 Mya or 140 Mya.

History

Historically the term Ranales was used to include the Ranunculaceae and related families, as described by Bentham and Hooker. This became replaced with Ranunculales by Melchior in 1964. The

Cronquist system The Cronquist system is a list of systems of plant taxonomy, taxonomic classification system of angiosperms, flowering plants. It was developed by Arthur Cronquist in a series of monographs and texts, including ''The Evolution and Classification of ...

(1981) also recognised the order, but placed it in the subclass Magnoliidae, in

class Class, Classes, or The Class may refer to: Common uses not otherwise categorized * Class (biology), a taxonomic rank * Class (knowledge representation), a collection of individuals or objects * Class (philosophy), an analytical concept used d ...

Magnoliopsida dicotyledons It used this circumscription: * order Ranunculales *: family

*: family Circaeasteraceae *: family

*: family Sargentodoxaceae *: family

*: family

*: family Coriariaceae *: family Sabiaceae In the Cronquist system, the Papaveraceae and Fumariaceae (including the plants in the optional family Pteridophyllaceae) were treated as a separate order Papaverales, placed in this same subclass Magnoliidae. The Cronquist

circumscription Circumscription may refer to: * Circumscribed circle * Circumscription (logic) *Circumscription (taxonomy) * Circumscription theory, a theory about the origins of the political state in the history of human evolution proposed by the American anthr ...

of Ranunculales is now known to be

polyphyletic A polyphyletic group is an assemblage that includes organisms with mixed evolutionary origin but does not include their most recent common ancestor. The term is often applied to groups that share similar features known as Homoplasy, homoplasies ...

. Sabiaceae is in a clade of basal eudicots separate from Ranunculales. Coriariaceae is now placed in the order

Cucurbitales The Cucurbitales are an order of flowering plants, included in the rosid group of dicotyledons. This order mostly belongs to tropical areas, with limited presence in subtropical and temperate regions. The order includes shrubs and trees, togeth ...

References

Bibliography

* * *

External links

NCBI Taxonomy Browser
{{Authority control Angiosperm orders Extant Aptian first appearances