ELEMENTARY BOTANY. 
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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 Root, 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 extremities 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 
nutriment 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 super- 
fluous 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 con- 
sist : 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 enable it to ripen its seed ; 3rd, of a 
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 , enclosing 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 flower-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 pre- 
ceding 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 angle 
formed by the leaf and the branch. When they appear at any other part of the plant, 
they are called adventitious. 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. 
§ 2. The Hoot. 
18. Roots ordinarily produce neither buds, leaves, nor flowers. Their branches, 
called fibres when slender and long, proceed irregularly from any part of their surface. 
19. Although roots proceed usually from the base of the stem or stock, they may 
also be produced from the base of any bud, especially if the bud lie along the 
ground, or is otherwise placed by nature or art in circumstances favourable for 
their development, or indeed occasionally from almost any part of the plant. They 
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