Family ( la, familia, plural ') is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between
order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of ...
genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...
. A family may be divided into subfamilies, which are intermediate ranks between the ranks of family and genus. The official family names are
Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through ...
in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to the family Juglandaceae, but that family is commonly referred to as the "walnut family". What belongs to a family—or if a described family should be recognized at all—are proposed and determined by practicing taxonomists. There are no hard rules for describing or recognizing a family, but in plants, they can be characterized on the basis of both vegetative and reproductive features of plant species. Taxonomists often take different positions about descriptions, and there may be no broad consensus across the scientific community for some time. The publishing of new data and opinions often enables adjustments and consensus.


The naming of families is codified by various international bodies using the following suffixes: *In fungal, algal, and botanical nomenclature, the family names of plants, fungi, and algae end with the suffix " -aceae", except for a small number of historic but widely used names including
Compositae The family Asteraceae, alternatively Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae w ...
and Gramineae. *In zoological nomenclature, the family names of animals end with the suffix " -idae".


The taxonomic term ' was first used by French botanist Pierre Magnol in his ' (1689) where he called the seventy-six groups of plants he recognised in his tables families ('). The concept of rank at that time was not yet settled, and in the preface to the ' Magnol spoke of uniting his families into larger ', which is far from how the term is used today.
Carl Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, ...
used the word ' in his ' (1751) to denote major groups of plants: trees, herbs, ferns, palms, and so on. He used this term only in the morphological section of the book, discussing the vegetative and generative organs of plants. Subsequently, in French botanical publications, from Michel Adanson's ' (1763) and until the end of the 19th century, the word ' was used as a French equivalent of the Latin ' (or '). In
zoology Zoology ()The pronunciation of zoology as is usually regarded as nonstandard, though it is not uncommon. is the branch of biology that studies the animal kingdom, including the structure, embryology, evolution, classification, habits, an ...
, the family as a rank intermediate between order and genus was introduced by Pierre André Latreille in his ' (1796). He used families (some of them were not named) in some but not in all his orders of "insects" (which then included all arthropods). In nineteenth-century works such as the ' of Augustin Pyramus de Candolle and the ' of George Bentham and Joseph Dalton Hooker this word ' was used for what now is given the rank of family.


Families can be used for evolutionary, palaeontological and genetic studies because they are more stable than lower taxonomic levels such as genera and species.

See also

* Systematics, the study of the diversity of living organisms * Cladistics, the classification of organisms by their order of branching in an evolutionary tree * Phylogenetics, the study of evolutionary relatedness among various groups of organisms * Taxonomy * Virus classification * List of Anuran families * List of Testudines families *
List of fish families This is a list of fish families sorted alphabetically by scientific name. There are 525 families in the list. __NOTOC__ A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - R - S - T - U - V - W - X - Y - Z - ...
List of families of spiders Spider taxonomy is that part of taxonomy that is concerned with the science of naming, defining and classifying all spiders, members of the Araneae order of the arthropod class Arachnida with more than 48,500 described species. However, there ar ...



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