  1. Vegetables or Plants are natural bodies endowed with organization and life, but destitute of voluntary motion and sense; and Botany is that branch of natural science which treats of their structure and functions, the systematical arrangement and denomination of their several kinds, and their peculiar properties and uses. 2. The principal parts of plants are the root; the herb or plant itself; and the fructification, or flower and fruit. 3. As it is the sole object of this introduction to describe, in a concise manner, the LinnÆan arrangement of plants, for the purpose of explaining the classification adopted in the present volume, the parts of fructification only will be mentioned. These are the calyx, corolla, stamens, pistil, seed-vessel, seeds, and receptacle. 4. The CALYX, or flower cup, is the green part which is situated immediately beneath the blossom. In some 5. The COROLLA, or blossom, is that coloured part of every flower on which its beauty principally depends. The leaves that compose it are denominated petals. Some flowers, as the convolvolus and campanula, have only a single petal; and others, as the rose and peony, have several petals. 6. In the centre of the flower there are two kinds of organs on which the fructification and re-production of the species more particularly depend. These are the stamens, and the pistil. The STAMENS are slender, thread-like, substances, which surround the pistil. They each consist of a filament or thread, and an anther or summit: the latter contains, when ripe, a fine dust or powder called pollen. This, though, to the naked eye, it appears a fine powder, is so curiously formed, and is so various in different plants, as to be an interesting object for the microscope. Each grain of it is, commonly, a membranous bag, round or angular, rough or smooth, which remains entire till it meets with any moisture; it then bursts and discharges a most subtile vapour. 7. The PISTIL is a prominent part, immediately in the centre of each flower, which adheres to the fruit, and is destined for the reception of the pollen. Some flowers have only one pistil; others have two, three, four, &c. and others more than can be easily counted. 8. At the foot of the pistil is situated the germen. This, when grown to maturity, has the name of 9. That part of every vegetable, which, at a certain state of maturity, is separated from it, and contains the rudiments of a new plant, is called the SEED. 10. The RECEPTACLE is the base which connects all the parts of fructification together, and on which they are seated. In some plants this is very conspicuous; and in none more so than the artichoke, of which it forms the eatable part, called the bottom. 11. The LinnÆan system of classification of plants is founded upon a supposition that the stamens represent the male, and the pistils the female parts of fructification. The whole vegetable creation has been distributed, by LinnÆus, into twenty-four classes. These are divided into orders, which are subdivided into genera or tribes; and these genera are further divided into species or individuals. 12. Of the CLASSES the discriminating characters are taken from the number, connexion, length, or situation of the stamens. In each of the first twenty classes there are stamens and pistils in the same flower; in the twenty-first class, the stamens and pistils are in distinct flowers on the same plant; in the twenty-second, in distinct flowers on different plants; in the twenty-third, in the same flower and also in distinct flowers; and in the twenty-fourth class they are not at all discernible. Thus:
13. The characters of the ORDERS are most commonly taken from the number of the pistils; but sometimes from circumstances relative to the stamens, pistils, or seed. Those of the first thirteen classes are taken from the number of pistils, thus:
The orders of the fourteenth class, Didynamia, are taken from the situation of the seeds; and are
The orders of the fifteenth class, Tetradynamia, are formed from a difference in the shape of the seed-vessel:
In the classes Monadelphia, Diadelphia, Polyadelphia, and Gynandria, the orders are taken from the number of stamens:
In the nineteenth class, Syngenesia, the orders are taken from the structure of the flower: Polygamia Æqualis,—all the florets alike. Polygamia superflua,—the florets of the centre perfect or united; those of the margin with pistils only, but all producing perfect seeds. Polygamia frustranea,—the florets of the centre perfect or united; those of the margin, in general, without either stamens or pistils. Polygamia necessaria,—the florets of the centre with stamens only; those of the margin with pistils only. The classes Monoecia and Dicoecia take their orders from the number and other peculiarities of the stamens:
In the class Polygamia there are three orders: Monoecia.Dioecia.Trioecia. The twenty-fourth class, Cryptogamia, has five orders: 1. Ferns. 2. Mosses. 3. Liverworts. 4. Flags. 5. Mushrooms. The LinnÆan system is professedly artificial. Its sole aim (observes Sir J. E. Smith) is to help any one to learn the name and history of an unknown plant in the most easy and certain manner. This is done by first determining its class and order; after which its genus is to be made out, by comparing the parts of fructification with all the generic characters of that order; and, finally, its species, by examining all the specific definitions of the genus. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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