CHAPTER I.
THE ORDER RANUNCULACEÆ: ILLUSTRATED BY THE RANUNCULUS, THE BUTTERCUP OR CROWFOOT, THE PEONY, THE ANEMONE, THE HEPATICA, THE CLEMATIS, THE CHRISTMAS ROSE, THE WINTER ACONITE, MONKSHOOD, THE LARKSPUR, AND THE COLUMBINE.
Such of my readers who may have formed their first ideas of the natural system from some order, the flowers of which bear a strong resemblance to each other, will be surprised at reading the names of the heterogeneous assemblage of plants at the head of this chapter; for surely no flowers can bear less resemblance to each other than the buttercup and the peony do to the columbine and the larkspur. There are, however, striking points of resemblance which link these flowers together; the principal of which are the number and disposition of the ovaries, or carpels as they are called in this case, which, though they grow close together, and sometimes even adhere to each other, are yet perfectly distinct; in the number and position of the stamens, which grow out of the receptacle from beneath the carpels; and in the leaves and young stems, when cut or pressed, yielding a thin yellowish juice, which is extremely acrid, and, in most cases, poisonous. The flowers of the plants belonging to Ranunculaceæ differ widely in their shapes; and all the incongruities that are only sparingly met with in other orders, are here gathered together. Some of the flowers have only a coloured calyx, as in the clematis; in others the calyx and corolla are of the same colour, as in the globe-flower, or so intermingled as to seem all one, as in the columbine; and in others the calyx forms the most ornamental part of the flower, as in monkshood and the larkspurs. In short, modern botanists seem to have placed this unfortunate order first, as though to terrify students on the very threshold of the science, and to prevent them from daring to advance any farther to penetrate into its mysteries.
THE GENUS RANUNCULUS.
The word Ranunculus will doubtless conjure up in the minds of my readers those very showy, double, brilliantly-coloured flowers, which flower in spring, and are generally grown in beds like tulips. These flowers form a species of the genus, under the name of Ranunculus asiaticus; and having been introduced from Asia, they have retained their botanic name from not having any English one. The honour of giving a name to the genus does not, however, rest on them, but belongs to a common English weed.
Every one who has travelled through England in the months of June and July, must have remarked the almost innumerable buttercups which glitter among the long grass of the meadows at that season; and those who observe closely, will have noticed that these brilliant little flowers are never found in poor soil, or in hilly situations, but in rich valleys where the grass is rank and luxuriant from abundance of moisture. It is this circumstance that has obtained for the buttercup the botanical name of Ranunculus, the word being derived from Rana, a frog, a creature that delights in moist places.
The buttercup being the type of the genus Ranunculus, and the order Ranunculaceæ, a close examination of its flowers will show the peculiarities which distinguish both the genus and the order. The characteristics of the order, as far as regards the number and position of the carpels and stamens, are shown in the section of the flower in the lower part of fig. 4; and those of the genus are, a green calyx of five sepals, and a bright coloured corolla of five petals (see a in fig. [4]); numerous stamens, the anthers of which are adnate, that is, with the filament growing up the back (see b); and numerous carpels (c) affixed to the upper part of the receptacle, which is drawn up in the shape of a cone to receive them. The flower shown in fig. 4, and the detached petal (e), given separately to show the little scale at
Fig. 4.—The flower of the common Butter-cup. its base, are of the natural size; but the anther b is magnified to show the curious manner in which it is affixed, for its whole length, to the filament. The section of the flower is also magnified to show the elevated receptacle, and the position of the carpels c and the stamens d with regard to each other. The line g shows the position of the corolla, and f that of the calyx, while the short line between the corolla and the stamens indicates the scale, which, from its being supposed to serve as a receptacle for honey, is sometimes called the nectary. The carpels, it will be observed, each consists of a broad part swollen in the centre, which is the ovary, with a curved part or beak at one end, terminating in a sharp point, which is the stigma. Each ovary contains only one ovule, and when the seed ripens, the carpel does not open to discharge it, but drops with the seed. When the flower is fully expanded, the green carpels may be seen in the centre, surrounded by the stamens, as shown at h in fig. 5; but after the petals drop, the stamens also disappear, and the carpels increase in size, till they assume the appearance shown at i, which shows the kind of head formed by the carpels on the receptacle after the flower has faded.