The great divisions of the science of plant life, or botany, are:
Structural Botany which treats of the gross anatomy of plants; Plant
Histology, of their minute anatomy; Plant Morphology, of the forms of
plants and their organs; Plant Physiology, of the functions of these
organs; Systematic Botany, of the relationship and classification of
plants; Geographical Botany, of the distribution of plants over the
surface of the globe; Paleobotany, of the vegetable life of past ages
and the successive appearance in the world of the great classes of
plants, as traced in their fossil remains; and Economic Botany, which
deals with the products of plants and their uses.
It is in the last division of the subject that our greatest practical
interest lies, and, consequently, it is best to reverse the general
order of treatment pursued by many botanists. Foremost in importance are
those plants grown for food, which form the great products of
_agriculture_, _gardening_ and _horticulture_. Scarcely less important
are those which yield fibers used for industrial purposes, such as
cotton, flax, jute and hemp; nor must we forget those producing
vegetable oils, rubber, and the large number of drugs so valuable to the
science of medicine in the alleviation of suffering.
(=See page 176 for scientific classification of the Vegetable or Plant
Kingdom.=)
[Illustration: =AN AUTUMN HARVEST OF BEAUTY AND PLENTY=]
_I. CEREALS, GRASSES AND FORAGE PLANTS_
Among all the plants in the world, the first place must be given to the
food-producing cereals upon which our very existence depends. The most
important among these are undoubtedly wheat, barley, oats, rye, rice,
Indian corn or maize, millets, sorghum and others less widely used. More
than one-half the whole population of the world subsists to a great
extent on rice, and the vital importance of wheat needs no
demonstration. For our present purposes the use of the word “cereal” is
extended to include buckwheat and other starch-yielding plants, but
these are not true cereals.