Binomial nomenclature (n.): A formal system of naming and categorizing species of plants and animals. All species have two names (comprising a Latin name), which follow the rules of Latin grammar but can be based on words from any language. The first name in the Latin name is the genus, and the second name is the species (Zantedeschia aethiopica is the scientific name for the calla lily flower). The scientific naming of plants is governed by International Code of Nomenclature for algae, fungi and plants (ICN). Read more about scientific names at "Plant Scientific Names."