''Tetracarpaea'' is the only

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

in the

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 ...

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Tetracarpaeaceae.Richard K. Brummitt. 2007. "Tetracarpaeaceae" pages 316-317. In: Vernon H. Heywood, Richard K. Brummitt, Ole Seberg, and Alastair Culham. ''Flowering Plant Families of the World''. Firefly Books: Ontario, Canada. .Klaus Kubitzki. 2007. "Tetracarpaeaceae" pages 456-457. In: Klaus Kubitski (editor). ''The Families and Genera of Vascular Plants'' volume IX. Springer-Verlag: Berlin;Heidelberg, Germany. Some

taxonomists In biology, taxonomy () is the scientific study of naming, defining ( circumscribing) and classifying groups of biological organisms based on shared characteristics. Organisms are grouped into taxa (singular: taxon), and these groups are given ...

place it in the family

Haloragaceae Haloragaceae (the watermilfoil family) is a eudicot flowering plant family in the order Saxifragales, based on the phylogenetic APG system. In the Cronquist system, it was included in the order Haloragales. Description The Haloragaceae ...

sensu lato ''Sensu'' is a Latin word meaning "in the sense of". It is used in a number of fields including biology, geology, linguistics, semiotics, and law. Commonly it refers to how strictly or loosely an expression is used in describing any particular co ...

'', expanding that family from its traditional

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 ...

to include '' Penthorum'' and ''Tetracarpaea'', and sometimes ''

Aphanopetalum ''Aphanopetalum'' is a genus of twining shrubs or vines in the family Aphanopetalaceae which are endemic to Australia. The genus is placed alone in family Aphanopetalaceae, which is in turn now placed in order Saxifragales. Until recently this ...

'' as well.Shuguang Jian,

Pamela S. Soltis Pamela Soltis (born November 13, 1957) is an American botanist. She is a distinguished professor at the University of Florida, curator at the Florida Museum of Natural History, principal investigator of the Laboratory of Molecular Systematics a ...

, Matthew A. Gitzendanner, Michael J. Moore, Ruiqi Li, Tory A. Hendry, Yin-Long Qiu, Amit Dhingra, Charles D. Bell, and Douglas E. Soltis. 2008. "Resolving an Ancient, Rapid Radiation in Saxifragales". ''Systematic Biology'' 57(1):38-57. (see ''External links'' below). ''Tetracarpaea'' has one

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

, ''Tetracarpaea tasmannica'', an

evergreen In botany, an evergreen is a plant which has Leaf, foliage that remains green and functional throughout the year. This contrasts with deciduous plants, which lose their foliage completely during the winter or dry season. Consisting of many diffe ...

, bushy

shrub A shrub or bush is a small to medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees by their multiple ...

from

subalpine Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures fall as elevation increases, causing the ecosystem to stratify. This stratification is a crucial f ...

areas of

Tasmania Tasmania (; palawa kani: ''Lutruwita'') is an island States and territories of Australia, state of Australia. It is located to the south of the Mainland Australia, Australian mainland, and is separated from it by the Bass Strait. The sta ...

. It is variable in height, from 1.5 to 10 dm. The leaves are shiny and small, with prominent veins, and the ends of the branches are crowded with small, white flowers. It is not known in cultivation, but has been grown from cuttings.John W. Wrigley and Murray Fagg. 2003. ''Australian Native Plants'' fifth edition. Reed New Holland, Australia. ''Tetracarpaea'' has an odd mix of characters, and during the nineteenth and twentieth centuries, its affinities remained obscure. It was variously

classified Classified may refer to: General *Classified information, material that a government body deems to be sensitive *Classified advertising or "classifieds" Music *Classified (rapper) (born 1977), Canadian rapper * The Classified, a 1980s American ro ...

by different authors, usually with considerable uncertainty.Matthew H. Hils, William C. Dickison, Terry W. Lucansky, and William Louis Stern. 1988. "Comparative anatomy and systematics of woody Saxifragaceae: Tetracarpaea". ''American Journal of Botany'' 75(11):1687-1700.

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 has shown that ''Tetracarpaea'' is a member of the Haloragaceae alliance, an

informal Formal, formality, informal or informality imply the complying with, or not complying with, some set of requirements ( forms, in Ancient Greek). They may refer to: Dress code and events * Formal wear, attire for formal events * Semi-formal att ...

group A group is a number of persons or things that are located, gathered, or classed together. Groups of people * Cultural group, a group whose members share the same cultural identity * Ethnic group, a group whose members share the same ethnic iden ...

composed of the families Aphanopetalaceae, Tetracarpaeaceae, Penthoraceae, and Haloragaceae. These are four of the fourteenAngiosperm Phylogeny Group. 2009. "An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III". ''Botanical Journal of the Linnean Society'' 161(2):105-121. (see ''External links'' below). or fifteen families in the

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 ...

Saxifragales Saxifragales is an order (biology), order of flowering plants in the Superrosids, superrosid clade of the eudicots. It contains 15 Families (biology), families and around 100 genera, with nearly 2,500 species. Well-known and economically import ...

Description

The following description is based on information from several sources.Armen L. Takhtajan (Takhtadzhian). ''Flowering Plants'' second edition (2009), pages 304-305. Springer Science+Business Media. . . (see ''External links'' below)

Frances Bodkin Frances (Fran) Bodkin (born 1937) is an Australian botanist and Dharawal elder. She is the author of ''Encyclopaedia Botanica: The Essential Reference Guide to Native and Exotic Plants in Australia'' (1986). In the 1970s, she helped establish the A ...

. 1986. ''Encyclopaedia Botanica: The Essential Reference Guide to Native and Exotic Plants in Australia''. Angus and Robertson, Publishers: New South Wales, Australia; London, England. ''Tetracarpaea tasmannica'' is a

glabrous Glabrousness () is the technical term for a lack of hair, down, setae, trichomes, or other such covering. A glabrous surface may be a natural characteristic of all or part of a plant or animal, or be due to loss because of a physical condition, ...

, erect and bushy

. It is variable in height, usually from 1.5 to 6 dm, but sometimes attaining a height of 1 m and a width of 7 dm. The

leaves A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...

are elliptic to

oblanceolate The following terms are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (that is, the leaf blade or 'lamina' is undivided) or compound (that is, the leaf blade is divided into two or more leaflets) ...

, about 25 mm long and 8 mm wide, on a

petiole Petiole may refer to: *Petiole (botany), the stalk of a leaf, attaching the blade to the stem *Petiole (insect anatomy) In entomology, petiole is the technical term for the narrow waist of some hymenopteran insects, especially ants, bees, and ...

about 2 mm long. The

veins Veins () are blood vessels in the circulatory system of humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are those of the pulmonary and fetal c ...

are prominent and end near the margin. The

margins Margin may refer to: Physical or graphical edges *Margin (typography), the white space that surrounds the content of a page *Continental margin, the zone of the ocean floor that separates the thin oceanic crust from thick continental crust *Leaf ...

are

serrate Serration is a saw-like appearance or a row of sharp or tooth-like projections. A serrated cutting edge has many small points of contact with the material being cut. By having less contact area than a smooth blade or other edge, the applied pr ...

crenate A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, fl ...

. On both surfaces, the

epidermis The epidermis is the outermost of the three layers that comprise the skin, the inner layers being the dermis and Subcutaneous tissue, hypodermis. The epidermal layer provides a barrier to infection from environmental pathogens and regulates the ...

is covered by a thick

cuticle A cuticle (), or cuticula, is any of a variety of tough but flexible, non-mineral outer coverings of an organism, or parts of an organism, that provide protection. Various types of "cuticle" are non- homologous, differing in their origin, structu ...

. The

inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

s are dense, erect,

terminal Terminal may refer to: Computing Hardware * Computer terminal, a set of primary input and output devices for a computer * Terminal (electronics), a device for joining electrical circuits together ** Battery terminal, electrical contact used to ...

raceme A raceme () or racemoid is an unbranched, indeterminate growth, indeterminate type of inflorescence bearing flowers having short floral stalks along the shoots that bear the flowers. The oldest flowers grow close to the base and new flowers are ...

s, up to 5 cm long. The

flower Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, m ...

s appear in

autumn Autumn, also known as fall (especially in US & Canada), is one of the four temperate seasons on Earth. Outside the tropics, autumn marks the transition from summer to winter, in September (Northern Hemisphere) or March ( Southern Hemisphe ...

. They are bisexual,

actinomorphic Floral symmetry describes whether, and how, a flower, in particular its perianth, can be divided into two or more identical or mirror-image parts. Uncommonly, flowers may have no axis of symmetry at all, typically because their parts are spirall ...

, and 5 to 10 mm wide. The 4

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 Etymology The term ''sepalum'' ...

s persist to the maturity of the fruit. The 4

petal Petals are modified leaves that form an inner whorl surrounding the reproductive parts of flowers. They are often brightly coloured or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''corol ...

s are

white White is the lightest color and is achromatic (having no chroma). It is the color of objects such as snow, chalk, and milk, and is the opposite of black. White objects fully (or almost fully) reflect and scatter all the visible wa ...

and

spatulate The following terms are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (that is, the leaf blade or 'lamina' is undivided) or compound (that is, the leaf blade is divided into two or more leaflets) ...

in shape. The

stamen The stamen (: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filament ...

s are either 4 or 8 in number. If 4, they are opposite (along the same radii as) the sepals. The

anther The stamen (: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filament ...

s are basifixed. The

ovary The ovary () is a gonad in the female reproductive system that produces ova; when released, an ovum travels through the fallopian tube/ oviduct into the uterus. There is an ovary on the left and the right side of the body. The ovaries are end ...

superior Superior may refer to: *Superior (hierarchy), something which is higher in a hierarchical structure of any kind Places * Superior (proposed U.S. state), an unsuccessful proposal for the Upper Peninsula of Michigan to form a separate state *Lak ...

and consists of 4

carpel Gynoecium (; ; : gynoecia) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of a flower; it consists of (one or more ...

s that are large compared to the rest of the flower. The carpels are usually separate, but occasionally 2 or 3 of them are fused at the base, or rarely, as far as halfway up. They are erect and stipitate with a suture along the ventral side. A

placenta The placenta (: placentas or placentae) is a temporary embryonic and later fetal organ that begins developing from the blastocyst shortly after implantation. It plays critical roles in facilitating nutrient, gas, and waste exchange between ...

runs along each side of the suture and bears 1 to 3 rows of numerous, tiny

ovule In seed plants, the ovule is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: the ''integument'', forming its outer layer, the ''nucellus'' (or remnant of the sporangium, megasporangium), ...

s. The ovules have been described as having one

integument In biology, an integument is the tissue surrounding an organism's body or an organ within, such as skin, a husk, Exoskeleton, shell, germ or Peel (fruit), rind. Etymology The term is derived from ''integumentum'', which is Latin for "a coverin ...

or two. The ovary hardly enlarges after

anthesis Anthesis is the period during which a flower is fully open and functional. It may also refer to the onset of that period. The onset of anthesis is spectacular in some species. In ''Banksia'' species, for example, anthesis involves the extension ...

. The

fruit In botany, a fruit is the seed-bearing structure in flowering plants (angiosperms) that is formed from the ovary after flowering. Fruits are the means by which angiosperms disseminate their seeds. Edible fruits in particular have long propaga ...

consists of 4 follicles joined at the base. The seeds are numerous and about ½ mm long.

Relationships

Named by

William Jackson Hooker Sir William Jackson Hooker (6 July 178512 August 1865) was an English botany, botanist and botanical illustrator, who became the first director of Kew Gardens, Kew when in 1841 it was recommended to be placed under state ownership as a botan ...

in 1840, the name ''Tetracarpaea'' refers to the four conspicuous and separate carpels.William Jackson Hooker. 1840. ''Hooker's Icones Plantarum'' volume 3. page 56 and table 264. Longman, Orme, Brown, Green, and Longmans: London, England. (see ''External links'' below). At that time, he wrote: Hooker did not use the modern system of suffixes for

taxonomic rank In biology, taxonomic rank (which some authors prefer to call nomenclatural rank because ranking is part of nomenclature rather than taxonomy proper, according to some definitions of these terms) is the relative or absolute level of a group of or ...

s. He placed ''Tetracarpaea'' in what would later be known as the family

Cunoniaceae Cunoniaceae is a family of 27 genera and about 335 species of woody plants in the order Oxalidales, mostly found in the tropical and wet temperate regions of the Southern Hemisphere. The greatest diversity of genera are in Australia and Tasmania ...

. From that time, until the end of the twentieth century, most authors put it in either Cunoniaceae,

Escalloniaceae Escalloniaceae is a family of flowering plants consisting of about 130 species in eight genera. In the APG II system it is one of eight families in the euasterids II clade (campanulids) that are unplaced as to order. More recent research has pro ...

, or

Saxifragaceae Saxifragaceae is a family of Herbaceous plant, herbaceous Perennial plant, perennial flowering plants, within the core eudicot Order (biology), order Saxifragales. The Taxonomy (biology), taxonomy of the family has been greatly revised and the ...

. It was believed that these three families were related, but today, they are placed in separate orders.Peter F. Stevens. 2001 onwards. Angiosperm Phylogeny Website At: Missouri Botanical Garden Website. (see ''External links'' below). It is now known that Cunoniaceae belongs in

Oxalidales Oxalidales is an order of flowering plants, included within the rosid subgroup of eudicots. This group comprises six families that contain approximately 2000 species in 58 genera. They are trees, shrubs or woody vines which are found in the wet ...

.Jason C. Bradford, Helen C. Fortune-Hopkins, and Richard W. Barnes. 2004. "Cunoniaceae". pages 91-111. In: Klaus Kubitski (editor). ''The Families and Genera of Vascular Plants'' volume VI. Springer-Verlag: Berlin;Heidelberg, Germany. Escalloniaceae is even more distant from ''Tetracarpaea'', being a member of an

asterid Asterids are a large clade (monophyletic group) of flowering plants, composed of 17 orders and more than 80,000 species, about a third of the total flowering plant species. The asterids are divided into the unranked clades lamiids (8 orders) and ...

group called the

campanulids Asterids are a large clade (monophyly, monophyletic group) of flowering plants, composed of 17 Order_(biology), orders and more than 80,000 species, about a third of the total flowering plant species. The asterids are divided into the unranked cl ...

.Richard C. Winkworth, Johannes Lundberg, and Michael J. Donoghue. 2008. "Toward a resolution of Campanulid phylogeny, with special reference to the placement of Dipsacales". ''Taxon'' 57(1):53-65. In the

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 ...

, it is assigned to the monofamilial order

Escalloniales Escalloniaceae is a family of flowering plants consisting of about 130 species in eight genera. In the APG II system it is one of eight families in the euasterids II clade (campanulids) that are unplaced as to order. More recent research has prov ...

Phylogenetic In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...

analysis of

DNA Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...

has placed ''Tetracarpaea'' in the order

, and in the "core Saxifragales", but no closer to Saxifragaceae. The family Saxifragaceae is now defined much more narrowly than it had been until 2001.Douglas E. Soltis, Robert K. Kuzoff, Mark E. Mort, Michael Zanis, Mark Fishbein, Larry Hufford, Jason Koontz, and Mary K. Arroyo. 2001. "Elucidating deep-level phylogenetic relationships in Saxifragaceae using sequences for six chloroplastic and nuclear DNA regions". ''Annals of the Missouri Botanical Garden'' 88(4):669-693.

History

After William Jackson Hooker named ''Tetracarpaea'' and placed it in Cunoniaceae, he was followed by

George Bentham George Bentham (22 September 1800 – 10 September 1884) was an English botanist, described by the weed botanist Duane Isely as "the premier systematic botanist of the nineteenth century". Born into a distinguished family, he initially studie ...

, who placed it in the same family.George Bentham. 1864. ''Flora Australiensis'' volume 2, page 445. Lovell Reeve & Co.: London, England. (see ''External links'' below). Bentham mistakenly attributed the name to "Hook.f." (

Joseph Dalton Hooker Sir Joseph Dalton Hooker (30 June 1817 – 10 December 1911) was a British botanist and explorer in the 19th century. He was a founder of geographical botany and Charles Darwin's closest friend. For 20 years he served as director of the Ro ...

), an error that is still repeated today. In 1865, George Bentham and Joseph Hooker moved ''Tetracarpaea'' from Cunoniaceae to Escalloniaceae.George Bentham and Joseph Hooker. 1865. ''Genera Plantarum'' volume 1, part 2, pages 648-649. Lovell Reeve & Co.; Williams & Norgate: London, England. (see ''External links'' below).

Adolf Engler Heinrich Gustav Adolf Engler (25 March 1844 – 10 October 1930) was a German botanist. He is notable for his work on plant taxonomy and phytogeography, such as ''Die natürlichen Pflanzenfamilien'' (''The Natural Plant Families''), edited with K ...

put ''Tetracarpaea'' in Saxifragaceae, but

defined A definition is a statement of the meaning of a term (a word, phrase, or other set of symbols). Definitions can be classified into two large categories: intensional definitions (which try to give the sense of a term), and extensional definitio ...

the latter so widely that it included what is now Escalloniaceae as a subfamily. Engler first placed ''Tetracarpaea'' in subfamily Escallonioideae, then later moved it to its own subfamily.H.G. Adolf Engler. 1930. "Tetracarpaea" page 183. In: H.G. Adolf Engler and Karl A.E. Prantl (editors). 1930. ''Die Natürlichen Pflanzenfamilien'' volume 18a. Verlag von Wilhelm Engelmann: Leipzig, Germany. In 1943,

Takenoshin Nakai was a Japanese botany, botanist. In 19191919. Notulae and Plantas Japoniae at Koreae X XI. The Botanical Magazine (Tokyo) 33(395): 193–194. and 1930,1930. Plantae Japonicae & Koreanae. The Botanical Magazine (Tokyo) 44(526): 508. he published p ...

put ''Tetracarpaea'' in a family to itself and was the first to use the term "Tetracarpaeaceae".Takenoshin Nakai. 1943. ''Chosakuronbun Mokuroku'': 244. 20 Jul 1943.James L. Reveal. 2008 onward. "A Checklist of Family and Suprafamilial Names for Extant Vascular Plants." At: Home page of James L. Reveal and C. Rose Broome. (see ''External links'' below). John Hutchinson did not follow suit, but placed it in Escalloniaceae.John Hutchinson ''The Families of Flowering Plants'' 3rd edition. 1973. Oxford University Press.

Arthur Cronquist Arthur John Cronquist (March 19, 1919 – March 22, 1992) was an American biologist, botanist and a specialist on Compositae. He is considered one of the most influential botanists of the 20th century, largely due to his formulation of the Cr ...

put ''Tetracarpaea'' in

Grossulariaceae ''Ribes'' () is a genus of about 200 known species of flowering plants, most of them native to the temperate regions of the Northern Hemisphere. The species may be known as various kinds of currants, such as redcurrants, blackcurrants, and whi ...

.Arthur John Cronquist. 1981. "Grossulariaceae" pages 558-561. In: ''An Integrated System of Classification of Flowering Plants''. Columbia University Press: New York, NY, USA. This family is now understood to contain only the genus

Ribes ''Ribes'' () is a genus of about 200 known species of flowering plants, most of them native to the temperate regions of the Northern Hemisphere. The species may be known as various kinds of currants, such as redcurrants, blackcurrants, and White ...

and 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 Saxifragaceae.

Armen Takhtajan Armen Leonovich Takhtajan or Takhtajian (; surname also transliterated Takhtadjan, Takhtadzhi︠a︡n or Takhtadzhian, pronounced takh-tuh-JAHN; 10 June 1910 – 13 November 2009), was a Soviet- Armenian botanist, one of the most important fi ...

has at different times put ''Tetracarpaea'' in Escalloniaceae and in Tetracarpaeaceae. Most recently, in 2009, he put it in Tetracarpaeaceae. In 1988, Matthew H. Hils,

et alii References Notes References Further reading * * External links * {{Latin phrases E ...

, did a detailed study of the

anatomy Anatomy () is the branch of morphology concerned with the study of the internal structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old scien ...

of the

wood Wood is a structural tissue/material found as xylem in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulosic fibers that are strong in tension and embedded in a matrix of lignin t ...

and leaves of ''Tetracarpaea''. They concluded that ''Tetracarpaea'' was much closer to Saxifragaceae than to Cunoniaceae or Escalloniaceae. The first

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 ...

studies of the order Saxifragales were inconclusive because their results had only weak statistical support. In 2008, by comparing

s of the entire invert repeat region of the

chloroplast A chloroplast () is a type of membrane-bound organelle, organelle known as a plastid that conducts photosynthesis mostly in plant cell, plant and algae, algal cells. Chloroplasts have a high concentration of chlorophyll pigments which captur ...

genome A genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding genes, other functional regions of the genome such as ...

, Shuguang Jian et alii were able to determine the position of ''Tetracarpaea'' within Saxifragales. These results had strong bootstrap support.