Part 13. The Departments Of Botany

13. The departments of botany. The peculiarities considered in classifying plants are chiefly such as concern the form, construction, and arrangement of parts. An understanding of botanical classification means, therefore, a knowledge of the structure of plants, just as an account of the different kinds of steam-engines (e. g., locomotives, including freight-engines, passenger-engines, switching-engines, etc.; stationary engines, including horizontal engines, pumping-engines, hoisting-engines, and so on) would be a description of the form and position of the different parts of their machinery. Moreover, not until we know about the different parts of a plant, as of a machine, are we in position to understand well what each part is for, and how they all work together. A knowledge of plant structure has thus a twofold importance. Similarly a knowledge of the materials which enter into the various parts of a plant, as of a machine, is necessary if we would understand its capabilities and usefulness.

So one question leads to another, the proper appreciation of one aspect of plants requiring also the study of other aspects. In this way have arisen the different departments of botany, each one representing a special point of view and all being necessary to a comprehensive understanding of the subject.

To the various departments have been given special names of which the following are the most important for a beginner to remember:-

Economic Botany

Economic Botany views plants in their relation to man's welfare. It is concerned with all the kinds which man uses for food, medicine, clothing, shelter, ornament, or for other purposes; and all which are harmful to him as weeds, poisons, or pests. The ways in which these plants are useful or harmful, and to what extent, to what peoples, for how long, and why-such questions as these it seeks to answer as far as possible.

Chemical Botany

Chemical Botany is the study of the properties and quantities of the various substances found in plants. Since the value of a useful plant often depends upon the presence of some special substance, such as sugar, the economic botanist has frequent occasion to learn about the chemistry of the plants with which he deals. Such knowledge is also necessary to an understanding of the life-processes of plants.

Systematic Botany

Systematic Botany is concerned with the accurate description, naming, and classification of plants. It investigates especially the resemblances and differences which botanists depend upon in their systems of arrangement.

Geographical Botany

Geographical Botany seeks to discover the native home of each plant, its migrations, if any, and the nature of its habitat, i. e., the surroundings amid which it grows wild.

Fossil Botany

Fossil Botany is the study of the remains of plants of former ages which have been preserved as fossils.

Biological Botany

Biological¹ Botany is the study of plants in regard to their ways of life as shown in the form and activities of their parts. Questions which relate simply to the form or structure of parts come within the subdepartment Vegetable Morphology ² or Morphological Botany. Such as concern simply the activities of parts, or the life-processes going on within them, belong to Vegetable Physiology³ or Physiological Botany. Finally, under Vegetable Ecology ⁴ or Ecological Botany come all questions as to how the different parts are adapted by their form and behavior to serve the welfare of the individual and the species, i. e., the relation of plants to their homes.

¹ Bi-o-log'-i-cal - Gr. bios, life; logos, logical account.

² Mor-phol'o-gy - Gr. morphe, form.

³ Phys-i-ol'o-gy - Gr. physis, nature.

⁴ E-col'o-gy - Gr. oikos, household.

Ecology considers the special ways in which plants solve the problems of their domestic economy, such as their manner of obtaining food, protecting themselves, and providing for their offspring. Ecology, also spelt oecology, is a word recently come into use among botanists, to designate a branch of botany which has been developed almost entirely within the memory of those now living. It has been used in rather various senses but generally with the meaning given above at least implied. Sometimes especial emphasis is put upon the peculiar associations or communities of plants that flourish in different kinds of homes, and upon the physical peculiarities of the homes themselves; but such matters are here referred in large part to geographical botany.