Each species of plant has its own unique scientific name which is expressed in Latin. This name remains the same for all countries of the world whatever their local tongue may be.
The first part, written with a capital letter, is the generic name, shared by all of the species belonging to the same genus or closely related group.
The second part is the specific name and only refers to that one particular unique species. Latin names are conventionally written either in italics or underlined.
For example, the tree that we know as Scots pine is in fact distributed right across Europe to Siberia. But all over the world this particular species is called Pinus sylvestris in Latin to avoid confusion from one country to another.
The scientific name is often descriptive of the tree itself. The first or generic name normally gives a clue to some general feature about that type of tree. The second or species name may refer to the same distinct feature of the tree (colour, size) or where it comes from (habitat, country) or who discovered it. For example Pinus sylvestris means ‘pine of the woods’.
Picture: Pinus sylvestris - Scots Pine © Royal Forestry Society
These local names can vary from country to country but may even vary within the same country. To eliminate any confusion scientists adopted the principle first proposed by an 18th century Swedish naturalist, Karl Linnaeus. Every animal or plant species has a double-barreled or ‘binomial’ scientific name. And the universal language adopted for this name is Latin.
Within the members of any one species there are often small natural local variations in shape, size or colour which are inherited genetic features and not just caused by the place or the conditions it grows under.
Where these clear and genetically inherited differences occur in the wild, the trees are called varieties and a third Latin or scientific name is added on the end. For example, the Highland variety of Scots pine with its distinctive short, blue-green needles becomes Pinus sylvestrisvar. Scotica.
Most tree species also have common names. These are the names you are used to hearing when we talk about trees, such as Oak, Ash and Scots pine, as in the example above.
Where varieties occur and are selectively bred for in cultivation, the tree is called a cultivar. The cultivar’s name comes after the scientific names and in single quotation marks; for example there is a gold-leaved form of Scots pine which was raised in a nursery and is known as Pinus sylvestris ‘Aurea.
When species of trees from the same genus but native to different parts of the world are brought together by human actions a hybrid may result which shows characters of both parents. One example occurred at Dunkeld in Scotland, where European and Japanese larches, normally found continents apart, were planted near each other and cross-fertilised producing the hybrid or Dunkeld larch. Its scientific name is written Larix x eurolepis. The x between the names indicates that both parents of this hybrid originate from the same genus.
More rarely, a hybrid arises between species coming from different genera. The Leyland cypress, commonly planted for hedges and screens in Britain, is a sterile cross between two American species; the Monterey cypress (Cupressus macrocarpa) and the Nootka cypress (Chamaecyparis nootkatensis). An x symbol is placed before the scientific names of such hybrids; so the Leyland cypress becomes x Cupressocyparis leylandii.
The Nootka cypress has been transferred recently to a new genus; its new name is Xanthocyparis nootkatensis so Leyland cypress should figure as x Cuprocyparis leylandii from now on.