Modern principles of nomenclature:
1. Botanical nomenclature is independent of Zoological nomenclature. Can have same names for plant and animal, e.g. Ricinus is a genus of plants and of lice.
2. Application of names is determined by type specimens.
3. Name of taxonomic groups is based on priority of publication starting with Species plantarum in 1753.--exception: nomina conservanda
4. Each taxon can bear only one correct name, the earliest that is in accordance with the rules.
5. Priority does not hold between ranks (application of the Kew Rule).