THE NAMING OF PLANTS
One of the problems for the gardener, and not only for the beginner, is the extraordinary confusion caused by botanical nomenclature. The subject is highly complicated, and though popularly supposed to be scientific, is not so. It is governed by nothing more than a set of rules that have grown up over the centuries. For practical purposes it is a great help to know something of these rules and how they evolved.
Right from the beginning one major difficulty had to be faced. A wild flower seldom confines itself to an area where all the inhabitants speak the same language. For instance, the common daisy of the British lawn grows almost every-where throughout Europe and western Asia. As the English name ‘daisy’ means nothing to a Frenchman, a German, or a Russian, and as botany andtranscend national boundaries, an international name is necessary, so that all nationalities can use it without any misunderstanding, and without the need for further description.
In the early days of botanical science, Latin was the one language that was universally understood among all educated Europeans. Botanists consequently chose Latin names for their plants.
Modern plant names are not nearly as complicated as they were more than two centuries ago. For example, many gardeners grow a small variegated maple usually called the box-elder, the leaves of which are rather like those of the ash, but marked in green and silver. When, in 1688, the great English naturalist Ray wanted to describe the natural green form of this tree, he wrote: Arbor exotica perperam eredita. All this was necessary to identify this pretty little tree to his botanical colleagues.
The present-day botanist has simplified matters by calling the variegated form Certain plants have a general similarity, and from early times botanists have tried to classify and group plants according to these likenesses, which usually occur in the fundamental structure of the flower. Superficial similarities, such as thorns, are ignored. For some while there was a general trend towards this classification, but it was not until theCarl Linne (or, in international Latin, Linnaeus) produced his book Genera Plantarum in 1737 that a sound system of naming plants originated.
Plants are grouped into large units, which may be likened to races, tribes and families. The genius of Linnaeus was that he evolved a system by which any plant could be identified by means of two names, sometimes with the addition of a third. The large units — the Divisions, Subdivisions, Classes and Families, as they are called — are ignored so far as the name of a single plant is concerned. They remain in the background. Linnaeus reduced his system t%a final unit, the. Each genus comprises all those plants that have certain similarities, within a much more restricted range than those characterizing a family, for example.
In the case of the small variegated is Acer — the maple genus, so named because it was the Roman name for some kind of maple.
But as there are several kinds of maple, such as the sycamore and common hedgerow maple, Linnaeus distinguished between the members of the genus Acer by adding another name, the specific epithet — describing the individual species within the genus. For the variegated maple he chose one of the words used by Ray, negundo, the name of a tropical plant with leaves similar to those of this particular maple. Thus Linnaeus named the Acer negundo normally has green leaves, while on this particular tree they are variegated. This variety therefore receives a third name, and becomes Acer negundo variegatum. Thus it is understood that the tree is the maple with leaves like those of the negundo but variegated. Moreover, this is understood by botanists of any nationality.
Once such a description of a plant is published, the botanical name generally remains the plant’s name for ever.
Names do change, however, because botany is a continually changing science. To take the variegated maple as an example — it will be noticed that the leaves are not like those of most other maples, such as the sycamore, but rather like those of the ash. Today some botanists believe that it is not a true maple, but a genus on its own, which they call Negundo. The tree thus becomes Negundo fraxinifolium, the ash-leaved negundo.
Although a specific epithet is some-times the odd name for a plant, such as negundo, it is more often a descriptive adjective. A few examples of well-known plant names are: the common rhododendron coming from the Black Sea district that was once called Ponticum; the-of-the valley, majalis, the convallaria of (that flowers in) May; the common nasturtium, , the big-flowered tropaeolum.
In a few cases the name of a person is used, usually someone connected with the flower. Many people grow Mlokose-witsch’s beautiful pale yellow paeony, which is known to the botanist as Paeonia.
These rules apply today to most of the trees and shrubs, and to the plants that the alpine gardener likes — that is, true natural species. The plants of the vegetable garden and, however, and a few shrubs such as roses and rhododendrons, have been interfered with by man, so that the result is far from natural. Whereas a natural species will reproduce itself in more or less the same pattern for countless generations, very few of the so-called man-made plants will ‘come true’ from seed. They are in-creased by , division of the roots, grafting, or budding.
Hybridization has given them a complex parentage and inheritance, which splits up again when seedlings are raised, and which in some cases causes sterility. A new name has quite recently been devised to describe this type of plant. This is ‘cultivar’, a sensible umbrella word that has brought into the nomenclature of plants such names as Peace for a particular rose, Cox’s Orange Pippin for a particular apple, and Pink Pearl for a particular rhododendron. The rules are somewhat similar to those for species — an adequate description must be attached to the generic and specific names, which appear in Latin and in italics; the cultivar name is given in whatever language it was first published.