Infraspecific name
Scientific name for any taxon below species rank in botany.
An infraspecific name is the scientific name for any taxon below the rank of species, known as an infraspecific taxon or infraspecies. These names are regulated by the International Code of Nomenclature for algae, fungi, and plants (ICN) and consist of a species name combined with an infraspecific epithet, separated by a connecting term that denotes the rank.
- field
- Botany
- governing_code
- International Code of Nomenclature for algae, fungi, and plants (ICN)
- key_ranks
- subspecies, variety, subvariety, form, subform
- connecting_terms
- subsp., var., subvar., f., subf.
- example
- Astrophytum myriostigma subvar. glabrum
Lore & Background
Infraspecific names are constructed from three parts: genus name, specific epithet, connecting term indicating rank, and infraspecific epithet. The connecting term is not part of the name but is required. Recommended abbreviations include subsp. for subspecies, var. for variety, subvar. for subvariety, f. for form, and subf. for subform. The ICN also allows Greek letters (α, β, γ) or other connecting terms in validly published names, though these are now deprecated but still legal and important as basionyms.
Reader's Guide
Infraspecific names are essential for precise classification below the species level in botany. They allow botanists to formally recognize and communicate about varieties, subspecies, forms, and other subdivisions within a species. The ICN requires that if infraspecific ranks are created, the type specimen of the species automatically becomes the type for an autonym repeating the specific epithet. Infraspecific epithets cannot be used in isolation; they must always accompany the species name. The system differs from zoological nomenclature, which uses trinomials without connecting terms, and from prokaryotic nomenclature, which governs only subspecies. Cultivated plant names fall under a separate code, the ICNCP.
Did You Know?
- The ICN allows Greek letters such as β to be used as connecting terms in infraspecific names, though these are now deprecated.
- An infraspecific name can have no defined rank, in which case '[unranked]' is used as the connecting term.
- If two infraspecific taxa with different types are accidentally given the same epithet, the earliest published name is legitimate and the other must be changed.
- The same infraspecific epithet can be reused within a species at different ranks only if the names are attached to the same type specimen.
Frequently Asked Questions
What is an infraspecific name in botany?
An infraspecific name is the formal scientific label assigned to any taxonomic group that sits below the species level. It identifies entities such as subspecies, varieties, forms, and their subdivisions within a single species.
Which ranks are covered by infraspecific nomenclature?
The key infraspecific ranks include subspecies, variety, subvariety, form, and subform. Each of these sits progressively lower in the hierarchy beneath the species name.
How is an infraspecific name actually constructed?
You take the full species name, add a connecting abbreviation that signals the rank (such as subsp., var., subvar., f., or subf.), and then append a unique infraspecific epithet. For instance, Astrophytum myriostigma subvar. glabrum pairs the species with the subvariety rank and its own epithet.
Which set of rules governs infraspecific names?
The International Code of Nomenclature for algae, fungi, and plants (ICN) sets out the regulations for constructing and publishing infraspecific names. It specifies the allowable connecting terms and formatting conventions for each rank.
Why do botanists bother with names below the species level?
Infraspecific names let researchers distinguish meaningful, recurring differences—like leaf shape, hairiness, or geographic adaptation—within what is still considered a single species. This finer-grained labeling supports more precise identification, conservation planning, and evolutionary study.
More in Taxonomy & Evolution 1-21
Spotted an error? Know more?
This is a living reference — every entry is fact-audited, and reader corrections feed straight into our audit queue. Suggest an edit · See this site's audit record