Forma (literally Latin for form) is used in a series of terms and abbreviations to describe variation in animals, especially insects. The terms or abbreviations are appended to the binomen or trinomen. Many 'typical specimens' may be described, but none should be considered absolute, unconditional or categorical. Forms have no official status, though they may be useful in describing altitudinal or geographical clines. Orders See taxonomy Insects are invertebrates that are taxonomically referred to as the class Insecta. ... In zoology, a binomen, or binominal name, is the name of a species. ... In zoology, a trinomen, or trinominal name, refers to the name of a subspecies. ... In population genetics, a cline is a gradual change of a character or feature (phenotype) in a species over a geographical area, often as a result of environmental heterogeneity. ...

forma geographica - f. geogr.

If used, nowadays usually denotes a part of a cline; for example for intergrades between subspecies in their area of contact.

forma localis - f. loc. In zoology, as in other branches of biology, subspecies is the rank immediately subordinate to a species. ...

As "f. geogr." but only local, more restricted in occurrence. See also small population size.

forma alta - f. alt. Species with a small population size are subject to a higher chance of extinction because their small population size makes them more vulnerable to genetic drift, resulting in stochastic variation in their gene pool, their demography and their environment. ...

Altitudinal features are not necessarily inherited, but may entirely be due to environment. The same applies to temperature or humidity-generated forms, such as:

forma vernalis - f. vern. (spring form)
forma aestivalis - f. aest. (summer form)
forma autumnalis - f. autumn. (autumn form)

aberratio - ab.

May be used for a single individual, for a small group such as an individual and its offspring, or for atypical individuals (for example, albinos).

Also used for commonly observed forms of a species, but in this case use of forma (f.) or morpha, accompanied by a descriptive name, is more conventional.

Notes: Albinism is a genetic condition resulting in a lack of pigmentation in the eyes, skin and hair. ... A Morph, meaning form (from the Latin morpha), is a zoological term that descibes local populations or subpopulations of a single species of animal that may or may not be phenotypically distinct from the larger population as a whole. ...

• A morph is a similar concept with a less restricted occurrence. As neither is officially recognised terminology, application can vary but, generally, morphs occur without geographical or seasonal restriction, and may constitute a significant part of the population. For a famous example, see Peppered moth.
• Botanical nomenclature is much more complex, with the use of varieties, subvarieties, and forms being formally regulated by the ICBN.

A Morph, meaning form (from the Latin morpha), is a zoological term that descibes local populations or subpopulations of a single species of animal that may or may not be phenotypically distinct from the larger population as a whole. ... Binomial name Biston betularia Linnaeus, 1758 Subspecies The Peppered Moth (Biston betularia) is a temperate species of night-flying moth often used by educators as an example of natural selection. ... Botanical nomenclature Plants are given formal names, governed by the ICBN. Within the limits set by the ICBN there is a separate set of rules, the ICNCP, for those plants in cultivation that require separate recognition, so-called cultivars. ... In botanical nomenclature, a subvariety (subvarietas) is a taxon at a rank below that of variety (varietas) but above that of form (forma): it is an infraspecific taxon. ... In botanical nomenclature, a form (forma) is a taxon at a rank below that of variety: it is an infraspecific taxon. ... The International Code of Botanical Nomenclature is the set of rules according to which plants are given their formal botanical names (scientific names). ...

See also

• Morph (zoology)
• Form (botany)