The order Crassulaceæ contains a number of low, succulent plants, with small, regular, star-like flowers. Some of them are well known as Stonecrops and House-leeks. Those of the Stonecrop group usually have cymes of flowers with perianth leaves in whorls of five, and stamens in two whorls.
One member of this group—the Orpine or Livelong (Sedum Telephium)—is not uncommonly found on shady wayside banks, especially near villages and on the outskirts of towns, where it is probably an escape from gardens. Its leaves are large, flat, oval or oblong, with serrate edges. The flowers have five sepals and five petals, are of a purple or crimson colour, and are clustered in close cymes.
We have now to consider several species of the order Umbelliferæ—a group of flowers which contains so many species, with often such close resemblances in general appearance, that it is always more or less puzzling to the beginner, especially as it is frequently necessary to note minute details of structure in order to determine a species.
The leading characteristic of the order is that denoted by its name; for the flowers, which are generally very small and white, are arranged in umbels. In a few instances these umbels are simple; but in most they are compound—that is, the stalks which radiate from the same point on the main peduncle, and thus form the primary umbel, give rise to the lesser stalks of the secondary umbels, which are similarly arranged and bear the flowers. There are often bracts at the base of the primary umbel, in which case they are termed the primary bracts; and there are frequently secondary bracts or involucels at the bases of the secondary umbels.
The Orpine or Livelong.
The flowers have a superior calyx; with five teeth; but this is often so inconspicuous that it appears like a mere rim round the top of the ovary. There are also five petals, which generally have their points turned inwards; and five stamens. The inferior ovary consists of two united carpels, surmounted by a fleshy disc that supports the petals and the stamens, and bears two styles.
Special attention must be given to the structure of the fruits of umbellifers, for a close examination of these is often necessary for purposes of identification. The two carpels are close together, with their adjacent surfaces flattened, and are fixed to a central axis called the carpophore. As the fruit ripens, the carpophore often divides, from above downwards, becoming Y-shaped; and the carpels, thus separated, are for a time suspended on its two arms. Each carpel is marked by vertical ridges, generally nine in number, five of them (primary ridges) being more prominent than the four intermediate or secondary ridges. The ridge on each side of the carpel, nearest to the fissure that divides the fruit into two parts, is often extended so as to form wings by means of which wind-distribution is greatly facilitated; and between the various ridges are the furrows of the fruit. In addition to these features, there are often narrow, light-coloured streaks running parallel with the ridges, in the walls of the fruit. There are usually six of these in each carpel, sometimes more than one in the same furrow, and they mark the positions of narrow oil-sacs or vittæ. Each carpel contains only one seed.
The Fool's Parsley.