The device used by biologists for identifying unknown organisms. Keys are constructed so that the user is presented with a series of choices about the characteristics of the unknown organisms. A taxonomic key is a device for quickly and easily identifying to which species an unknown plant belongs. The key consists of a series of choices, based on observed features of the plant specimen.it is often referred to as a dichotomous key.
These tables were developed by Waller as an image-based dichotomous key, pre-dating by almost 100 years the text-based dichotomous keys in the first edition of Flora Fran ç aise (1778) by Jean Baptiste Lamarck, who is generally given priority for the development of the dichotomous key.There are seven main taxonomic ranks: kingdom, phylum or division, class, order, family, genus, species.