24

INTRODUCTION TO BOTANY.

a distinguishing mark from any other flower in the same class andorder.

We shall hereafter enumerate nil the different Genera comprisedin the "British Flora as they s~and in the classes and orders, with theirdescriptions : but it should be understood that in doing this the limitsof this Pocket Compendium will not admit of going into the charactersat full length.

We shall therefore content ourselves with describing them by theiressentia! characters alone, i. e. those particular marks and forms of theparts of fructification, which distinguish them from the other alliedgenera.

The next Subdivision, i. e.

THE SPECIES OF PLANTS,

is formed from the characters drawn either from the particular shapeof the leaves, flowers, branches, roots, &c. &c. These we must also forthe above reasons describe by their essential characters also.

It will however be necessaiy for the student to understand a little ofterminology, as descriptive of the different parts which the species ofplants are determined from; and by a little attention he will be enabledsoon to find out the name of any plant he may meet with ; as nothingmore will be wanting than practical investigation, made by studyingthe plants in their places of growth, and comparing them with theirwritten descriptions.

Root {Radix). This is generally considered that part of the plantwhich is under ground, and which draws nourishment from the earth,necessary to the plant's existence.

Trunk (Truncus). This in its structure is very similar to the root ;•so much so indeed, that Linnaeus has considered the stalk as a rootabove ground. And we find that the generality of stalks may by arti-ficial modes be caused to throw out roots. Hence the mode of propa-gating plants by cuttings.

Under this head may be considered the following, viz : —The Caulis. A stalk supporting both the leaves and fructification.Culmus (Slraw). A stalk peculiar to the grasses and all kinds ofgrain.

Stipes. A kind of stalk peculiar to the Fungi. It is also used tosignify the stem supporting the Ferns and Palms.

Branches (Rami). An extension of the trunk. After the first year'sgrowth they divide to considerable extent, and become larger and morespreading as the tree increases in growth.

Leaves (Folia). These are defined tc be fibrous and cellular, and tocfiffer greatly in form and size : they are however mostly flat, and ap-pear to be the same as the branehes, only differing fa structure. Leaves