Forma is a Latin word meaning "form". Both the word "forma" and the word "form" are used interchangeably as informal terms in biology:
In botanical nomenclature, a form (forma, plural formae) is one of the "secondary" taxonomic ranks, below that of variety, which in turn is below that of species; it is an infraspecific taxon. If more than three ranks are listed in describing a taxon, the "classification" is being specified, but only three parts make up the "name" of the taxon: a genus name, a specific epithet, and an infraspecific epithet.
The abbreviation "f." or the full "forma" should be put before the infraspecific epithet to indicate the rank. It is not italicised.
For example:
Forma is an American electronic band from Brooklyn. The group released two full length albums for Spectrum Spools in 2011 and 2012. After a lineup change (John Also Bennett replaced founding member Sophie Lam), they released an EP for NYC techno label The Bunker New York in 2014.