INTRODUCTION. V 



botanical species may be an annual or a perennial, a herbaceous perennial or an under- 

 shrub, an underslirub or a shrub, a shrub or a tree, according to climate, treatment, 

 or variety. 



14. Plants are usually terrestrial, that is, growing on earth, or aquatic, i. e. growing 

 in water ; but sometimes they may be found attached by their roots to other plants, 

 in which case they are epiphytes when simply growing upon other plants without 

 penetrating into their tissue, parasites when their roots penetrate into and derive more 

 or less nutriment from the plant to which they are attached. 



15. The simplest form of the perfect plant, the annual, consists of — 



(1) The Hoot, or descending axis, which grows downwards from the stem, divides 

 and spreads in the earth or water, and absorbs food for the plant through the extremi- 

 ties of its branches. 



(2) The Stem, or ascending axis, which grows upwards from the root, branches and 

 bears first one or more leaves in succession, then one or more flowers, and finally one 

 or more fruits. It contains the tissues or other channels (217) by which the nutri- 

 ment absorbed by the roots is conveyed in the form of sap (192) to the leaves or other 

 points of the surface of the plant, to be elaborated or digested (218), and afterwards 

 redistributed over different parts of the plant for its support and growth. 



(3) The Leaves, usually flat, green, and horizontal, are variously arranged on the 

 stem and its branches. They elaborate or digest (218) the nutriment brought to them 

 through the stem, absorb carbonic acid gas from the air, exhaling the superfluous 

 oxygen, and returning the assimilated sap to the stem. 



(4) The Flowers, usually placed at or towards the extremities of the branches. 

 They are destined to form the future seed. When perfect and complete they consist : 

 1st, of a pistil in the centre, consisting of one or more carpels, each containing the 

 germ of one or more seeds ; 2nd, of one or more stamens outside the pistil, whose 

 action is necessary to fertilize the pistil or enuble it to ripen its seed ; 3rd, of & perianth 

 or floral envelope, which usually encloses the stamens and pistil when young, and 

 expands and exposes them to view when fully formed. This complete perianth is 

 double ; the outer one, called Calyx, is usually more green and leaf-like ; the inner 

 one, called the Corolla, more conspicuous, and variously coloured. It is the perianth, 

 and especially the corolla, as the most showy part, that is generally called the flower 

 in popular language. 



(5) The Fruit, consisting of the pistil or its lower portion, which persists or remains 

 attached to the plant after the remainder of the flower has withered and fallen off. 

 It enlarges and alters more or less in shape or consistence, becomes a seed-vessel, en- 

 closing the seed until it is ripe, when it either opens to discharge the seed or falls to 

 the ground with the seed. In popular language the term fruit is often limited to such 

 seed-vessels as are or look juicy and eatable. Botanists give that name to all seed- 

 vessels. 



16. The herbaceous perennial resembles the annual during the first year of its 

 growth ; but it also forms (usually towards the close of the season), on its stock (the 

 portion of the stem and root which does not die), one or more buds, either exposed, 

 and then popularly called eyes, or concealed among leaves. These buds, called leaf- 

 buds, to distinguish them from floioer-buds or unopened flowers, are future branches 

 as yet undeveloped ; they remain dormant through the winter, and the following 

 spring grow out into new stems bearing leaves and flowers like those of the preceding 

 year, whilst the lower part of the stock emits fresh roots to replace those which had 

 perished at the same time as the stems. 



17. Shrubs and trees form similar leaf-buds either at the extremity of their branches, 

 or along the branches of the year. In the latter case these buds are usually axillary, 

 that is, they appear in the axil of each leaf, i. e. in the ai:gle formed by the leaf and 

 the branch. When they appear at any other part of the plant they are called adventi- 

 tious. If these buds by producing roots (19) become distinct plants before separating 

 from the parent, or if adventitious leaf-buds are produced in the place of flowers or 

 seeds, the plant is said to be viviparous or proliferous. 



