CHAPTER IV
THE FAMILIES OF FLOWERING PLANTS AND THEIR RELATIONSHIP
THERE are perhaps over 150,000 different kinds of flowering plants known in the world to-day, but the flowerless ones are fewer than these in numbers. No one really knows how many thousands of the cryptogams there may be in the world, for all of them have not yet been described, and there are doubtless thousands of which we merely suspect the existence. Flowering plants are so much better known, and have for 2,000 years been the subject of scientific writings, that their relationships and obvious groupings into families are fairly definite and often easily recognizable.
In our ordinary discussions or gossip of neighbors or relatives, the absolutely necessary starting point is to know their name. Their acquirement of this by christening, or by the adoption of it through the usage of parents, settles for life what they will be called. Plants are also christened, and that ceremony is one of the most important events in our subsequent discussion of them.
Plant Names and How They Are Acquired
As we always have at least two names, one to show that we are a Smith, for instance, and another to fix us as John Smith, so all plants have two names, sometimes three.
And because plants come from all over the world and are studied and loved by people of many different languages, it became necessary very early in the descriptive writings about them to hit upon some device that should insure the name of a particular plant being the same all over the world, whether used by a student in the Imperial University of China, or by a garden enthusiast in Connecticut. At the time when this need for christening plants with names that would pass current throughout the world was getting to be a crying necessity, the language of all learned men was Latin, so it was natural that they should give Latin names to plants. That practice has continued to the present day, and there are even now some botanists that cling to the old custom of describing the newly christened plant in Latin. In the olden days this was always done, so that much of our knowledge of plants has come down to us from early books written wholly in Latin. The unfamiliarity of Latin to most of us, and the terrifyingly difficult spelling of some plant names, has resulted in many people saying: “God made the flowers, but the devil gave them names.” Nevertheless, these Latin names are the only ones we can use without endless confusion, just as we bear the names assigned to us by our parents, and no others.
If we were to go out into the country and pick up a wild rose which seemed to be different from any other rose, it would be necessary, in order to talk about it subsequently, to give it a name. After carefully searching through all the books about roses and finding out that it really is a new kind of rose rather than merely being new to us, we should then be ready to christen our new find. As we have said, all plants bear two names. One of these is a general one, like Smith, for instance, and the other more specific, like John. These general names of plants, and they are always their first names, are, because they fix the plant as belonging to a particular group, known as generic names. The generic name of violets, for instance, is Viola; of buttercups, Ranunculus; of wheat, Triticum; of corn, Zea; and of roses, Rosa. Our new rose then bears, without any act of ours, the generic name Rosa, which was applied to roses many years ago, and must therefore be used for all subsequently discovered roses. This generic name of Rosa, like all other generic names, tells us that roses are a well-recognized group of plants, all more like one another than like blackberries, for instance, and because of this they are said to all belong to the same genus. A genus (plural, genera) is a group of different plants, all more like one another than like anything else. To go back to our new Rosa, we must now apply its second and more specific name. If it were a white rose, and had never before been described, we should almost certainly use for its second name something signifying its color and assign alba as the obvious Latin equivalent of white. The second name is always called the specific name, because it shows us that from all other roses our new Rosa alba differs in being white. It is of the genus Rosa, but it is also and forever after a recognized member of Rosa, to which a specific name has been applied—in other words, Rosa alba is a species of rose. Species are thus plants more like one another than they are like any other member of the genus to which they belong. Rosa alba is a species quite unlike Rosa lucida, or Rosa carolina, or all the other scores of roses already known or described. At the time of christening Rosa alba, we should not only enter its name in a book, as ours would be in a parish register, but do much more than that. We should so carefully describe it and, preferably, illustrate it with a picture that no one coming after could ever mistake Rosa alba for any other rose. It can be readily seen that the christening of new plants is very nearly as serious an affair as christening babies, and furthermore, it is only to be attempted by experts. Because this has not always been done, many plants have been christened two or three times. Of course, these subsequent christenings do not seriously matter, for plants, like ourselves, should have only one specific name, the first applied to them. But their subsequent christenings by the careless and ignorant have enormously increased the difficulty of talking or writing about plants. These spurious names are common throughout the literature of botany and are known as synonyms.
The thing to remember about plants, so far as our need for classifying them is concerned, is that they belong to different species which might almost be considered the unit or simplest recognizable category into which they may be sorted. For convenience, we sort species into genera which may well be considered the next highest category in which plants are grouped. The grouping of genera into tribes, of tribes into families, and of families into still larger categories, has nothing to do with their names, but everything to do with our understanding of how they are related to one another, and what these different categories mean in the great collection of plants all about us. In other words, it reduces to a definite system an apparently hopelessly mixed-up mass of plants that, without some contrivance of the sort, would simply be a lot of totally unrelated specimens of plant life. Actually they are grouped in fairly definite categories, some of which are easily recognizable, and all of which fit into that great scheme of nature where everything may seem chaotic, but to the observant it is really a very pattern of order. What it all means and how plants have been grouped into families will be explained, now that we understand how they have acquired their generic and specific names.
PLANT FAMILIES AND ORDERS
A scientist once visiting in Bulgaria noticed that the peasants in that country frequently lived over a hundred years and, in trying to find out the reason, he discovered that they drank large quantities of sour milk. This is alive with a definite kind of bacterium that is of great benefit to the digestive apparatus, and therefore helps in the prolongation of life. In Bulgaria, in other words, a certain food habit of the people has resulted in a definite prolongation of life and fixes that population as of somewhat different characteristics from people not addicted to sour milk. In Japan a whole race lives largely on fish and rice, and while this is not the cause of their yellow skin, it is almost surely the cause of their generally small stature. Many of the English are tall, light-haired, and blue-eyed people, fond of outdoor life and sports, and among the most highly developed of the peoples of the earth. The climate of that island, their generally large consumption of meat and the outdoor life of so many of them, have resulted in quite definite characteristics that make the typical Englishman an easily distinguishable type.