underfamily

An underfamily is a taxonomic rank used in biological classification, specifically within the context of the Linnaean system of nomenclature. It is a subdivision of a family, and is used to group closely related genera that are not closely enough related to form a separate family. The term "underfamily" is derived from the Latin word "sub," meaning "under" or "below," and "familia," meaning "family."

Underfamilies are often used in the classification of plants, particularly in the Angiosperms (flowering plants), where they help to organize the vast number of genera into more manageable groups. For example, the family Fabaceae (legumes) is divided into several underfamilies, including the Faboideae and the Caesalpinioideae.

In the classification of animals, underfamilies are less commonly used, as the relationships between genera are often more clearly defined and can be accommodated within families. However, they can be used in cases where a family is particularly large or diverse, and where the relationships between genera are not yet fully understood.

The use of underfamilies is a matter of convention and can vary between different taxonomic systems. In some cases, the rank of underfamily may be skipped altogether, and genera may be placed directly within a family. Conversely, in other cases, additional ranks such as tribe or subtribe may be used to further subdivide a family.

In summary, an underfamily is a taxonomic rank used to group closely related genera within a family. It is a useful tool for organizing the vast number of genera in the plant kingdom, and is less commonly used in the animal kingdom. The use of underfamilies is a matter of convention and can vary between different taxonomic systems.