* Potamogeton natans - Plate 21 D. † Acorns Calamus - Plate 21 C.

Somewhat similar to this in the minutiae of its structure, though differing considerably in aspect, is the Common Rush (Juncus communis), a plant of the Juncaceous family. This well-known plant, one form of which is frequently called Juncus effusus, has a short, creeping, matted rootstock, which produces dense tufts of cylindrical leafless stems, two to three feet high, sheathed at the base by a few brown scales, and tapered above into a fine point. Some of these stems are barren and seem to resemble leaves, whilst others bear on one side, towards the top, a loosely clustered, irregular, compound, bracteated panicle of small brownish flowers. These consist of a regular, dry, calyx-like perianth of six pointed segments, usually three, but sometimes six, stamens, a single style, with three stigmas, and a many-seeded very obtuse capsule, opening in three valves. The plant is very abundant in wet situations, almost all over the northern hemisphere, and in some parts of the southern. Another form of the same species, called Juncus conglomeratus, has the clusters dense and compact, so as to form roundish heads. Both forms are used for platting into mats and chair-bottoms, and the pith of their stems is formed into wicks for candles.

The Flowering Rush,* belonging to the Butomaceous family, which it typifies, is of a more ornamental character than the preceding; indeed, it has truly been said to be a greater adornment to the banks of our rivers than any other British wild-flower. It is a perennial aquatic herb, with a thick creeping rootstock, from which spring up the clusters of long, erect, triangular, sedge-like leaves, which are broad and sheathing at the base. The flower-stem is stout, leafless, rushlike, three or four feet high, bearing a large, simple umbel of numerous showy pale rose-coloured or pinkish flowers, and having an involucre of three lance-shaped bracts at the base of the umbel. The flowers are nearly an inch in diameter, the perianth formed of six ovate nearly equal spreading segments; within this are nine stamens, and, in the centre, six erect carpels, connected below, tapered above into short styles, and each containing numerous small seeds. It is a very handsome aquatic plant, quite deserving of cultivation. By some authorities, the family to which it is referred is included in that of the Alismaceous plants.

The beautiful family of Iridaceous plants, another of the regular-flowered groups of Monocotyledons to which allusion has already been made, is further illustrated by the Yellow Flag,† found abundantly in marshy places and by the sides of watercourses. There, as Shelley writes, "where the embower-ing trees recede, and leave a little space of green expanse, the cove is closed by meeting banks, whose yellow flowers for ever gaze on their own drooping eyes reflected in the crystal calm." This plant has a good deal the aspect of the Sweet Flag (Aco-rus Calamus),excluding the flowers,however, which are remarkably showy and petaloid,instead of being reduced to the appearance of green closely packed scales. The plant has a thick, horizontal root-stock or rhizome, as it is called, from which grow up the long sword-shaped leaves, three or four feet long, stiff erect and of a glaucous green, equitant or alternately bestriding each other at the base, those on the flower-stem (which does not grow so high as the leaves) being shorter. The flowers, which are large and showy, are produced two or three in succession, from the axils of sheathing bracts near the upper part of the stem; they are erect, of a bright yellow colour, the three outer or sepaline segments of the perianth being large and reflexed, broadly ovate, contracted into a claw at the base, and the three inner or petaline divisions, small, oblong, and erect. There are three stamens opposite the sepaline segments, and over these the petal-like appendages of the three stigmas are arched; these appendages are longer and larger than the petaline segments, yellow, two-cleft at top, and toothed on the edge. The ovary is inferior, becoming a three-cornered, oblong capsule. Many beautiful garden plants belong to this family, Iris itself being an extensive and ornamental genus, besides which there are Gladiolus, Ixia, Crocus, and numerous others of equal beauty.

* Butomus umbellatus - Plate 21 A. † Iris Pseud-acorns - Plate 20 D.

The Orchidaceous family is a group of plants having, like the foregoing, an inferior ovary, but singularly irregular flowers. It is a very extensive and, including the exotic species, a remarkably varied group of plants. Our illustration among summer flowers, the Bee Ophrys,* or Bee Orchis, as it is more commonly called, gives but a faint idea of the grotesque beauty of many tropical species. The peculiar characteristics of the group have been adverted to in describing the Spotted Palmate Orchis and the Ladies' Slipper, so that we may now confine our remarks to the Bee Orchis before us. This plant is furnished with a pair of tubers, of which one is growing and the other waning: the former being in process of formation as a store of nutriment for the stem of the succeeding year, while the latter has been exhausted by the growth of the stem of the present year, which has, as it were, sucked out its vitals. The stem rises from nearly a foot to a foot and a half in height, erect, leafy near the base, and terminating in a loose spike of curiously coloured flowers. The leaves are oblong or lanceolate, the upper ones being the smaller. The flowers have at the base a bract as long as the ovary, which latter simulates a flower-stalk, the flowers being really sessile; they consist of three ovate spreading or reflexed sepals, which are always more or less tinged with pink, two petals, which are smaller than the sepals and nearly erect, and a part, very unlike all the rest, called the lip or labellum, which is broad and convex, of a rich velvety-brown, downy at the sides, smooth in the middle, and variously marked by paler lines or spots; while on each side is a small downy lobe turned under, and at the point three terminal ones, which are turned under so as to be quite concealed. It is this lip which is supposed to resemble a bee. The column is erect, with a distinct curved beak above the anther. The plant is found plentiful in some of the southern or eastern parts of England, growing in dry pastures in limestone districts.