Family ( la, familia, plural ') is one of the eight major hierarchical
In biological classification, taxonomic rank is the relative level of a group of organisms (a taxon) in an ancestral or hereditary hierarchy. A common system consists of species
In biology, a species is the basic unit of Taxonomy (biol ...
Linnaean taxonomy can mean either of two related concepts:
# The particular form of Taxonomy (biology), biological classification (taxonomy) set up by Carl Linnaeus, as set forth in his ''Systema Naturae'' (1735) and subsequent works. In the ta ...
. It is classified between order
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
. A family may be divided into
In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family (biology), family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oi ...
, which are intermediate ranks between the ranks of family and genus. The official family names are
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 is the formal, scientific naming of plants. It is related to, but distinct from Alpha taxonomy, taxonomy. Plant taxonomy is concerned with grouping and classifying plants; botanical nomenclature then provides names for the ...
, 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 International Code of Zoological Nomenclature (ICZN) is a widely accepted Convention (norm), convention in zoology that rules the formal scientific name, scientific naming of organisms treated as animals. It is also informally known as the I ...
, 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 (; 23 May 1707 – 10 January 1778), also known after his Nobility#Ennoblement, ennoblement in 1761 as Carl von Linné#Blunt, Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalise ... used the word ' in his ' (1751) to denote major groups of plants: trees
In botany, a tree is a perennial plant with an elongated Plant stem, stem, or trunk (botany), trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondar ..., herb
In general use, herbs are a widely distributed and widespread group of plants, excluding vegetables and other plants consumed for macronutrients, with savory or aromatic properties that are used for flavoring and garnishing food, for medicina ...s, fern
A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The Polypodiophyta, polypodiophytes include all living pteridop ...s, 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
Michel Adanson (7 April 17273 August 1806) was an 18th-century French botanist and naturalist who traveled to Senegal to study flora and fauna. He proposed a "natural system" of taxonomy distinct from the binomial system forwarded by Carl Linnae ...'s ' (1763) and until the end of the 19th century, the word ' was used as a French equivalent of the Latin ' (or ').
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, animal kingdom, including the anatomy, structure, embryology, evolution, Biological clas ..., 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 arthropod
Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a Segmentation (biology), segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and Arth ...s).
In nineteenth-century works such as the ' of Augustin Pyramus de Candolle
Augustin Pyramus (or Pyrame) de Candolle (, , ; 4 February 17789 September 1841) was a Swiss people, Swiss botany, botanist. René Louiche Desfontaines launched de Candolle's botanical career by recommending him at a herbarium. Within a couple ... and the ' of George Bentham
George Bentham (22 September 1800 – 10 September 1884) was an English botanist
Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a s ... and Joseph Dalton Hooker
Sir Joseph Dalton Hooker (30 June 1817 – 10 December 1911) was a United Kingdom of Great Britain and Ireland, British botanist and explorer in the 19th century. He was a founder of geographical botany and Charles Darwin's closest friend ... 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.
Biological systematics is the study of the diversification of living forms, both past and present, and the Correlation and dependence, relationships among living things through time. Relationships are visualized as evolutionary trees (synonyms: c ..., the study of the diversity of living organisms
Cladistics (; ) is an approach to Taxonomy (biology), biological classification in which organisms are categorized in groups ("clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically ..., the classification of organisms by their order of branching in an evolutionary tree
In biology, phylogenetics (; from Greek language, Greek wikt:φυλή, φυλή/wikt:φῦλον, φῦλον  "tribe, clan, race", and wikt:γενετικός, γενετικός  "origin, source, birth") is the study of the evolutionary his ..., the study of evolutionary relatedness among various groups of organisms
Taxonomy is the practice and science of categorization or classification (general theory), classification.
A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are ...
* Virus classification
Virus classification is the process of naming viruses and placing them into a Alpha taxonomy, taxonomic system similar to the classification systems used for cell (biology), cellular organisms.
Viruses are classified by phenotypic characteristics, ...
* List of Anuran families
* List of Testudines families
There are fourteen extant family (biology), families of the order (biology), order Testudines, an order of reptile. The testudines are some of the most ancient reptiles alive, with only the tuataras considered more primitive. There are approximatel ...
* List of fish families
* List of families of spiders