Plants are grouped in families, in such a way as to bring together those which show a natural relationship to each other. As the characters on which this natural grouping rests are frequently obscure, it has been thought best to employ in this book an artificial arrangement, designed to enable the beginner to identify a strange plant by means of its more obvious characters. In the first place the plants dealt with are arranged in ten colour groups. As considerable variation occurs in colour, and as the value placed by different people on a particular colour shade is not always the same, it would be well if, for example, a purplish flower could not be found under purple, to try under pate purple.
As some of the groups are rather large, it has been found necessary to subdivide them. The method of working the classification employed may best be understood if we take a concrete example. Suppose we have found a specimen of the Greater Stitchwort. It is a white flower, so we turn to the table at the beginning of " White Flowers," and find that these are arranged in three groups. As the Stitchwort has neither composite-heads nor umbels, it must belong to group III; here there are two sub-groups, in the second of which, B, it must be placed, as its leaves are quite simple: we then count the number of stamens, which we find to be ten, and so learn that it is among plants 55-65. It only remains for us to read over the descriptions of these, and to compare our plant with the illustrations, to determine which fits it properly, and so find its name to be Stellaria Holostea, the Greater Stitchwort.
With the aid of this book it will be found possible to identify a considerable number of our commoner or more striking wild plants; but only about one sixth of the total number of British species is mentioned. If the interest of the reader carries him beyond the limits of these pages, and is sufficient to nerve him to face the difficulties of a more minute examination, and of a more extended technical vocabulary, we may conclude by advising him to turn his attention to one of the standard works on the subject. Of these two may be mentioned: - Babington's Manual of British Botany, 9th ed., and Bentham and Hooker's Handbook of the British Flora, 8th ed. As neither is illustrated, we might add, as a companion volume, Smith's Illustrations of the British Flora, 6th ed.
For general works on other branches of botany the list of books given in Dr. Marie Stopes' Modern Botany should be consulted.