Ranunculales is anorder offlowering plants. Of necessity it contains the familyRanunculaceae, the buttercup family, because the name of the order isbased on the name of a genus in that family. Ranunculales belongs to aparaphyletic group known as thebasal eudicots. It is the mostbasal clade in this group; in other words, it issister to the remaining eudicots. Widely known members includepoppies,barberries,hellebores, andbuttercups.

Ranunculales Temporal range:124–0 Ma PreꞒ Ꞓ O S D C P T J K Pg N Early Cretaceous–Recent
Ranunculus repens
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Order:	Ranunculales Juss.exBercht. &J.Presl[1]
Families
See text

TheAngiosperm Phylogeny Group recognized seven families in Ranunculales in theirAPG III system,published in 2009. In the precedingAPG II system, they offered the option of threesegregate families as shown below.^[1]

• order Ranunculales

  familyBerberidaceae

  familyCircaeasteraceae

  [+ familyKingdoniaceae ]

  familyEupteleaceae

  familyLardizabalaceae

  familyMenispermaceae

  familyPapaveraceae

  [+ familyFumariaceae ]

  [+ familyPteridophyllaceae ]

  familyRanunculaceae

Note: "+ ..." = optionally separate family (that may be split off from the preceding family).

Under this definition, well-known members of Ranunculales includebuttercups,clematis,columbines,delphiniums, andpoppies.

Aphylogeny of Ranunculales was published in 2009, based onmolecular phylogenetic analysis ofDNA sequences. The authors of thispaper revised the subfamilies andtribes of the order.^[2] This is reflected in the subsequent revision of the APG, APG IV (2016).^[3]

The analysis revealed that the order consisted of threeclades, 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.

The fossil formLeefructus, described in 2011, has been recognized as a member of this order.^[4]Leefructus mirus shows fully developed leaves; stem and flower that are very similar in structure to those of the modernbuttercups. The fossil is dated to 125Mya (million years old) and it not only proves that Ranunculales is an ancient group ofeudicots but demonstrates that the wholeangiosperm 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 offlowering plants. The fact thatLeefructus 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.^{[citation needed]}

Another fossil has been described with the nameTeixeiraea, also from theCretaceous ofPortugal.^[5] The genusAtli from theLate Cretaceous of Canada appears to have had aliana-like growth habit.^[6]

According tomolecular clock calculations, the lineage that led to Ranunculales split from other plants about 132Mya^[7] or 140 Mya.^[8]

Historically the termRanales was used to include the Ranunculaceae and related families, as described byBentham and Hooker. This became replaced with Ranunculales byMelchior in 1964.^{[citation needed]}

TheCronquist system (1981) also recognised the order, but placed it in thesubclassMagnoliidae, inclassMagnoliopsida [= dicotyledons]. It used this circumscription:^{[citation needed]}

• order Ranunculales

  familyRanunculaceae

  familyCircaeasteraceae

  familyBerberidaceae

  familySargentodoxaceae

  familyLardizabalaceae

  familyMenispermaceae

  familyCoriariaceae

  familySabiaceae

In the Cronquist system, the Papaveraceae and Fumariaceae (including the plants in the optional family Pteridophyllaceae) were treated as a separate orderPapaverales, placed in this same subclass Magnoliidae. The Cronquistcircumscription of Ranunculales is now known to bepolyphyletic. Sabiaceae is in a clade of basal eudicots separate from Ranunculales. Coriariaceae is now placed in the orderCucurbitales.^{[citation needed]}

• NCBI Taxonomy Browser