When the scientific naming of organisms was developing in the 16th to 18th centuries, the universal language of science was Latin. That is why the names use the Latin language. Greek-derived words are also used, and indeed words from many other languages, but they are all treated as being Latin. The basic principle is that scientific names, which are often called Latin names, are used worldwide, enabling scientists speaking different languages to communicate readily with one another. In the examples given above, the species that is variously called lords-and-ladies, parson-in-the-pulpit, cuckoo-flower, cuckoo-pint, ram’s-horn, and adder’s-tongue is Arum maculatum, not only in Britain but everywhere else in the world. English bluebell is everywhere Hyacinthoides non-scripta; North American bluebell is Mertensia virginica; Scottish bluebell and English harebell are Campanula rotundifolia; English toothwort and German Schuppenwurz are Lathraea squamaria; North American toothwort and English bittercress are species of Cardamine, and another species of English cuckoo-flower is Cardamine pratensis. In a global context, therefore, using common names can be ambiguous and highly confusing, whereas using scientific names enables more precise communication.
The current system of biological nomenclature dates back to the mid-18th-century, when Swedish naturalist Carolus Linnaeus (Carl von Linné) published his Species plantarum and Systema naturae (Linnaeus, 1753, 1758), in which a binomial, sometimes called binominal or binary, i.e. “two-name”, system was introduced. A binomial is the name of a species (where a species is considered to be the basic taxonomic unit comprising a group of individual organisms). A binomial consists of the name of a genus, e.g. Quercus, followed by what Linnaeus called a nomen triviale (trivial name), which is now called a specific epithet, e.g. robur, hence Quercus robur. This is a very user-friendly method for naming millions of species of organisms, because even if you know a species only by its name, you already know to which genus it belongs. It is much easier to remember the names and taxonomic placement of a relatively small number of genera than it is a very large number of species.
TAXONOMY AND NOMENCLATURE ARE DIFFERENT THINGS
Taxonomy (or systematics) is the science that deals with circumscribing and classifying organisms in a system. Nomenclature is the provision of means of reference, i.e. names, for those organisms. Classifications are in a constant state of change as new data come to light, especially with regard to evolutionary relationships inferred from molecular studies. To pretend that any particular classification ought to be fixed as the final word on a group of organisms would be grossly unscientific. Because of the nature of the current nomenclatural system, this perpetual process of taxonomic reappraisal inevitably causes a certain degree of nomenclatural change. Changing a family to a subfamily results in a name change, e.g. Pyrolaceae becomes Pyroloideae. Moving a genus from one family to another does not result in a name change. Moving a species from one genus to another necessarily causes a name change because under the binomial system the accepted generic name is part of the species name, e.g. when the species originally described as Hy-
CHAPTER 1
INTRODUCTION11
