THE ORDER ROSACEÆ, ILLUSTRATED BY DIFFERENT KINDS OF ROSES; THE POTENTILLA; THE STRAWBERRY; THE RASPBERRY; SPIRÆA; KERRIA OR CORCHORUS JAPONICA; THE ALMOND; THE PEACH AND NECTARINE; THE APRICOT; THE PLUM; THE CHERRY; THE APPLE; THE PEAR; THE MOUNTAIN ASH; THE WHITE BEAM TREE; QUINCE; PYRUS OR CYDONIA JAPONICA; THE HAWTHORN; THE INDIAN HAWTHORN; THE MEDLAR; PHOTINIA; ERIOBOTRYA; COTONEASTER; AMELANCHIER; BURNET; AND ALCHEMILLA OR LADIES’-MANTLE.

All the numerous plants which compose this large order agree more or less with the rose in the construction of their flowers, though they differ widely in the appearance of their fruit. They all agree in having the receptacle dilated, so as to form a lining to the lower part of the calyx, and in the upper part of this lining the stamens and petals are inserted above the ovary; and the anthers are innate, that is, the filament is inserted only in the lower part. The leaves also have generally large and conspicuous stipules; and they are frequently compound, that is, composed of several pairs of leaflets, placed exactly opposite to each other; though the leaves themselves are never opposite to each other, but are placed alternately on the main stem. These characters are common to the order; but the plants included in it differ from each other so much in other respects, that it has been found necessary to redivide RosaceÆ into tribes, of which the following six contain plants common in British gardens.

TRIBE I.—ROSEÆ.

The flowers of the wild Rose have the lower part of the calyx tubular and fleshy (from being lined with the dilated receptacle) and the upper part divided into five leafy sepals, which enfold the bud, and remain on after the expansion of the corolla. In Rosa Fosteri, (see fig. 20,) and its near ally the Dog rose (R. canina), the sepals (a) do not extend far beyond the petals of the bud; but in some species, as in Rosa cinnamonea and its allies, the sepals are so large and long, that they assume the character of little leaves, Fig.21.—Ovary of the Ayrshire rose with a detached seed. Fig.21.—Ovary of the Ayrshire rose with a detached seed. The corolla is cup-shaped, and it is composed of five equal petals, each of which is more or less indented in the margin, as shown at b. In the centre of the flower the receptacle forms a kind of disk which completely fills the opening or throat of the calyx; in most species covering the carpels and their styles and only leaving the stigmas free, though in the Ayrshire rose (R. arvensis), and its allies, the styles are united, so as to form a column, which projects considerably above the disk (see fig. 21). The pitcher-shaped part of the calyx when the corolla falls becomes the hip (fig. 20 c), and serves as a covering or false pericarp to the numerous bony carpels or nuts which contain the seed. These nuts are each enveloped in a hairy cover (see fig. 20 d, and fig. 21 a,) and each contains only one seed which it does not open naturally to discharge: hence, the seeds of roses when sown are a long time before they come up. Fig. 22 is the ripe fruit of Rosa cinnamonea, cut in two to Fig.22.—Ripe fruit and detached seed of a Rose. Fig.22.—Ripe fruit and detached seed of a Rose. show the nuts. The leaves are pinnate, consisting of two or more pairs of leaflets, and ending with an odd one. The leaves are furnished with very large stipules (see fig. 20 e); and the stems have numerous prickles (f), which differ from thorns in being articulated, that is, they may be taken off without tearing the bark of the stem on which they grow, only leaving the scar or mark, shown at g. The leaves of the sweet briar are full of small glands or cells filled with fragrant oil, which may be distinctly seen in the shape of little white dots, when held up to the light; and this is the reason of their delightful perfume. When the leaf is rubbed between the fingers, the thin skin that covers the cells is broken, and the oil being permitted to escape, the fragrance is increased. There are only two genera in this tribe, viz. Rosa and Lowea, the latter containing only what was formerly called Rosa berberifolia, and which has been thought worthy of being made into a separate genus principally on account of its having simple leaves without stipules, and branched prickles.

TRIBE II.—POTENTILLEÆ OR DRYADEÆ.

The plants belonging to this tribe agree more or less in the construction of their flowers with the well-known showy plants called Potentilla, but my readers will probably be surprised to hear that the raspberry and the strawberry are included among them. If, however, they compare the flower of the Potentilla with that of the strawberry, they will find them very much alike. In both there is a calyx of ten sepals, and a cup-shaped corolla of five petals; and in both the stamens form a ring round an elevated receptacle, on which are placed numerous carpels. Here, however, the resemblance ceases, for as the seeds of Potentilla ripen, the receptacle withers up in proportion to the swelling of the carpels, till it becomes hidden by them; while in the strawberry the receptacle becomes gradually more and more dilated, swelling out and separating the bony carpels still farther and farther from each other, till at last it forms what we call the ripe fruit. I have already had several times occasion to mention the receptacle, which though seldom seen, or at least noticed, by persons who are not botanists, is a most important part of the flower, and one that assumes a greater variety of form than any other. Sometimes, as we have seen in several of the RanunculaceÆ and LeguminosÆ, it is a mere disk or flat substance serving as a foundation to hold together the other parts of the flower; and at other times we have found it drawn out into a thin membrane and divided into a kind of leaves, as it is among the carpels of the tree-peony; but in no plants that I have yet had occasion to describe does it assume such strange forms as in RosaceÆ.

The flower of the strawberry (Fragaria vesca) has a green calyx of ten sepals; five of which are much smaller than the others, and grow a little behind them, the large and small ones occurring alternately. The corolla is cup-shaped, and in five equal petals; the stamens are numerous and arranged in a crowded ring round the carpels, which are placed on a somewhat raised receptacle. The carpels or nuts resemble those of the rose, but they have no hairy covering, and indeed look hard and shining on the surface of the distended receptacle, or polyphore as it is called in its metamorphosed state. The carpels when ripe do not open to discharge the seed, and consequently as they are sown with the seeds, the young plants are a long time before they appear. The strawberry has what is called ternate leaves, that is, leaves consisting of three leaflets; with large membranous stipules. The calyx is persistent, that is, it remains on till the fruit is ripe.

The Raspberry (Rubus IdÆus) differs widely from the strawberry in many particulars, notwithstanding their being included not only in the Fig.23.—Flowers and Fruit of the Raspberry. Fig.23.—Flowers and Fruit of the Raspberry. same natural order, but in the same tribe. The calyx has only five sepals (a in figure 23); and though the corolla has five petals (b), they do not form a cup-shaped flower. In the centre are the carpels, the form of which is shown of the natural size at c, and magnified at d, the latter showing that each has a separate style and stigma. As the raspberry advances, the petals drop, and the receptacle becomes elevated into what is called a torus, as shown of the natural size at e; bearing the carpels upon it, which gradually swell out and soften, till each becomes a little pulpy fruit, full of juice, and having the stone or seed in the centre. While this change is taking place, the stamens gradually wither and fall off, and the stigmas disappear, the style shrivelling up to the appearance of a hair; the pulpy carpels have also become so pressed against each other, as to adhere together, and the whole, with the persistent calyx, now assumes the appearance shown at f. As soon as the carpels become ripe they cease to adhere to the torus, and they may be pulled off and eaten (the torus, or core as it is called, being thrown away): each carpel will be found to inclose a very hard seed or stone, as shown at g. If the Raspberry, instead of being gathered, be suffered to remain on the stalk, the juicy carpels dry up, and fall with the seed inclosed. The stems of the Raspberry are biennial, that is, they do not bear till they are two years old, after which they die; but the roots are perennial, and they are always sending up fresh suckers, so that the same plants will bear for many years in succession, though not on the same stems. The stems are generally erect, and prickly like the rose; and the leaves on the bearing stems have three leaflets, while those on the barren stems have five; and in both cases the leaflets are covered with white down on the under side. All the different kinds of Bramble, such as the Dewberry, Blackberry, &c., agree with the Raspberry in the construction of their fruit, though they differ in the number of their leaflets, the size and colour of their flowers, and other minor particulars.

Several other genera belong to this tribe, among which may be mentioned Geum Avens, or Herb Bennet, the carpels of which have each a hooked style; Sieversia separated from Geum, because the carpels end in a straight feathery awn; and Tormentilla, the flowers of which bear a general resemblance to those of Potentilla, but which have an eight-parted calyx; a corolla of four petals; sixteen stamens, and dry wrinkled carpels on a depressed receptacle. All these genera my readers will find it interesting to procure flowers of, in order to compare them with each other. This and the preceding tribe are considered by some modern botanists to form the order RosaceÆ; the other tribes being formed into separate orders.

TRIBE III.—SPIRÆEÆ.

The only genera in this tribe which contain well-known plants are SpirÆa and Kerria. In SpirÆa the calyx is five-cleft (see a in fig. 24) and lined with the dilated receptacle, forming a shallow tube or rather cup for the reception of the carpels. There are five small roundish petals (b), and from twenty to fifty stamens (c), which project very far beyond them. In the centre are from two to five carpels (d), which are something like those of the raspberry when young, but afterwards become of the kind called follicles; each carpel contains from two to six seeds affixed to its inner suture, and they are dehiscent—that is, they open naturally at the top to discharge the seed (see e). The flowers are set very close together, and from this circumstance, combined with their small size and projecting stamens, they look like fine filigree work; hence the popular English names given to S. salicifolia or Bridewort, Queen’s needle-work, &c. The flowers of this species are in spicate racemes, but others are in corymbs, as in S. bella; or in panicles, as in S. ariÆfolia.

Kerria is a genus containing only one species, the plant which was formerly called Corchorus japonica; the calyx is united at the base, but divided in the upper part into five lobes; three of them obtuse, and the other two tipped with a little point called a mucro. There are about twenty stamens about the same length as the petals arising from the calyx, and five roundish carpels containing one seed each. The leaves are simple, and the stipules awl-shaped. Till lately only a double-flowered variety was known in Britain; but about 1832, the single-flowered plant was introduced from China. Corchorus, the genus in which this plant was originally placed, is nearly allied to the lime-tree.

TRIBE IV.—AMYGDALEÆ.

This tribe is distinguished by the fruit, which is what botanists call a drupe, that is, a stone fruit. The principal genera included in this tribe are Amygdalus, the Almond; Persica, the Peach and Nectarine; Armeniaca, the Apricot; Prunus, the Plum; and Cerasus, the Cherry. All these genera contain more or less of prussic acid, which is found to exist principally in the leaves and kernels; and they all yield gum when wounded.

The flowers of the common Almond (Amygdalus communis) appear, as is well known, before the leaves, bursting from large scaly buds, which when they open throw off the brown shining bracts in which they had been enwrapped. The calyx is somewhat campanulate, with the upper part cut into five teeth or lobes, and it is lined by the dilated disk. There are five petals, and about twenty stamens, both inserted in the lining of the calyx. The anthers are innate, and they differ from most of the other plants yet described in being only one-celled. The ovary is also only one-celled, and there are generally two ovules, though the plant rarely ripens more than one seed. The leaves are simple, and they have very small stipules. When the petals drop, the ovary appears covered with a thick tough downy pericarp, within which is the hard stone or nut, the kernel or almond of which is the seed.

The Peach (Persica vulgaris) was formerly included in the same genus as the almond; and in fact there is but little botanical difference. The flowers are the same both in construction and appearance; and the leaves are simple like those of the almond, and, like them, they are conduplicate (that is, folded together at the midrib) when young. The only difference indeed is in the fruit; for, as everybody knows, the stone of the peach has not a dry tough covering, like that of the almond, but a soft and melting one full of juice, and the stone itself is of a harder consistence, and deeply furrowed, instead of being only slightly pitted. The fruit of the peach has thus a fleshy pericarp, the pulp or sarcocarp of which is eatable, and a furrowed nut or stone, inclosing the seed or kernel, which is wrapped up like that of the almond, in a thick loose skin.

The Nectarine (P. lÆvis) only differs from the peach in the epicarp, or outer covering of the pulpy part, being smooth instead of downy. Of both fruits there are two kinds, one called free-stone, from their parting freely with the stone; and the other cling-stone, from the stone clinging to the fibres of the pulp.

The Apricot (Armeniaca vulgaris) agrees with the preceding genus in its flowers; but it differs in its fruit, its stone being sharp at one end and blunt at the other, with a furrow on each side, but the rest of the surface smooth. Thus my readers will perceive that the Peach and the Apricot, though so different from each other as to be recognised at a glance, are yet botanically so very closely allied, as to be distinguished only by the stone. The leaves indeed differ in form, but in other respects they are exactly the same.

The Sloe (Prunus spinosa) is supposed by some botanists to be the origin of our cultivated plum, though others make it a separate species under the name of Prunus domestica. The flowers in both are solitary (see fig. 25), and consist of a five-toothed calyx (a) which is united at the base, and in the lining of which the stamens are inserted as shown at (b). The ovary has a thick style and capitate stigma (c), and the fruit is a drupe (d). In these particulars therefore the plum agrees with the preceding genera; but it will be found to differ in the skin of the pericarp, which is quite smooth and covered with a fine bloom; this, indeed, and its stone being pointed at both ends constitute the chief botanical distinctions between the fruit of the plum and that of the apricot, as in other respects they are alike. Both the plum and the apricot have footstalks, and in this differ from the peach and the nectarine, which are without. The leaves of the plum differ from those of the other genera in being convolute, that is, rolled up, in the bud.

The Cherry (Cerasus vulgaris) differs from the plum in the skin of the pericarp being destitute of bloom, and in several flowers springing from each bud, in what botanists call a fascicled Fig.26.—Flowers and stone of the Cherry. umbel (see a) in fig. 26. The pedicels (b) are also much longer; the petals (c) are indented in the margin; the style (d) is more slender; and the stone (e) is smooth and much more globose. The number of the stamens, and the manner in which they are inserted in the lining of the calyx, is the same in both genera (see f); but the leaves are different, for those of the Cherry are folded down the middle, when young, like those of the peach and almond; while those of the plum are rolled up.

The genus Cerasus is divided into two sections, the first containing those species which have their flowers in bunches, and on long footstalks, as in the common Cherry; and the second those which have their flowers in racemes on short footstalks, as in the Bird-cherry (Cerasus Padus); the Mahaleb, or Bois de Sainte Lucie (Cerasus Mahaleb); the common Laurel (Cerasus Lauro-Cerasus); and the Portugal Laurel (Cerasus lusitanicus). These plants are so different from the common Cherry both in flowers and fruit, as far as can be judged from their general appearance, as scarcely to be recognised; but when closely examined their botanical construction will be found the same. Formerly only two genera were included in this tribe—viz. Amygdalus, which comprised the Peach and Nectarine as well as the Almond; and Prunus, which included the Apricot and the Cherry.

TRIBE V.—POMEÆ.

The common apple (Pyrus Malus) may be considered the type of this tribe, which comprehends not only what we are accustomed to call kerneled fruit, but also the Hawthorn, Cotoneaster, and other ornamental shrubs and low trees. The flower of the apple bears con siderable resemblance to the flowers of the genera already described, but the petals (see a in fig. 27) are oblong, rather than roundish.

The calyx (b) is tubular in the lower part, and the limb is divided into five lobes. The receptacle lines the lower part of the calyx, and forms a disk, filling its throat, in which the stamens and petals are inserted. There are five ovaries, the styles of which are for half their length united, leaving the upper part and the stigmas free; and the ovaries themselves, now become cells, are enclosed in a cartilaginous endocarp, which forms what we call the core of the Apple, and which adheres firmly to the tubular part of the calyx. There are two ovules in each cell, placed side by side, but generally only one seed in each becomes perfectly ripe. As the seeds advance, the fleshy tube of the calyx swells out and becomes what we call the apple; while the leafy part or lobes of the limb remain on, and form the eye. Fruit of this kind are called pomes.

The Pear (Pyrus communis) differs from the apple in the shape of the fruit (see a in fig. 28), which tapers towards the footstalk, instead of being umbilicate, that is, indented at the point of the insertion of the footstalk, as is the case with the Apple. The construction of the flowers in both species is the same, except that the styles are quite free for their whole length in the Pear, and not partially united into a column as in the Apple. This distinction, and some others, have been thought, by some botanists, sufficient to constitute the Apple and its allied species into a separate genus under the name of Malus. The leaves of the Pear differ from those of the Apple in being the same colour on both surfaces, whereas those of the Apple are covered with a white down on the under side.

Besides the Apple and the Pear, and their respective allies, which form two distinct sections of the genus Pyrus, that genus, being a very extensive one, is divided into several other sections, all the plants contained in which may be arranged under two heads: viz., those that formerly constituted the genus Sorbus; and those that were once called Aronia.

The Mountain Ash (Pyrus aucuparia) may be considered as a fair specimen of most of the trees belonging to the Sorbus division. By the details of the flowers of this species given in fig. 29, it will be seen that the petals (a) are very small and concave; and the calyx (b) is tubular, and five-cleft. There are three styles, as shown at c; and the stamens (d), which project far beyond the petals, are inserted in the disk. The fruit (e) is a pome with three seeds (f) enclosed in a cartilaginous membrane, like the core of the apple or pear. The leaves of the Mountain Ash are impari-pinnate, that is, they consist of several pairs of leaflets, terminating in an odd one; and the flowers are produced in corymbs. The White Beam-tree (Pyrus Aria), the wild Service (P. torminalis), and several similar trees, belong to this division and have the same kind of fruit as the Mountain Ash. The true Service, however, differs in its fruit being generally shaped like a pear, though there is a variety with apple-shaped fruit. One species (P. pinnatifida) has the leaves lobed to the midrib, instead of being cut into leaflets; and this gives the name to the species, leaves of this description being called pinnatifid. The leaves of the genus Pyrus often have their petioles dilated and somewhat stem-clasping at the base; but they have generally only small stipules.

Among the other plants included in the genus Pyrus, may be mentioned the beautiful shrub now called Pyrus arbutifolia, which has been successively included in the genera CratÆgus, Aronia, and Mespilus; and P. ChamÆmespilus, which has been successively called CratÆgus, Mespilus, and Sorbus. There are several beautiful low shrubs belonging to this division of the genus Pyrus.

The genus Cydonia, the Quince, differs from Pyrus in having its seeds arranged in longitudinal rows, instead of being placed side by side. In the Chinese Quince there are thirty seeds in each row, arranged lengthways of the fruit. The ovary of this genus consists of five cells, each containing one row of seeds, the seeds being covered with a kind of mucilaginous pulp. The well-known plant, formerly called Pyrus japonica, has been removed to the genus Cydonia on account of its ovary and the disposition of its seeds, which are decidedly those of the Quince. It differs, however, from the common Quince in its seeds, which are arranged in two rows in each cell.

The common Hawthorn (CratÆgus Oxyacantha) has generally only two styles (see a, fig. 30), but the Fig.30.—Flower and fruit of the Hawthorn. number of styles varies in the many different species included in the genus from one to five. The corolla, calyx, and stamens are the same as in the other genera included in this tribe, but the petals (b) are rounder and rather more indented. The seeds vary from one to five, each being enclosed in a bony covering, or stone, the whole being surrounded by the fleshy part of the calyx, which forms the eatable part of the Haw. In some of the species the haws are so large as to appear like little apples; but they may be always easily distinguished by the ripe ovary, or case which incloses the seed, being bony; whereas in all the varieties of Pyrus, the outer part of the ovary is cartilaginous, like the core of the apple. The seeds of the Hawthorn are a long time before they come up, from the hardness of this bony covering, which does not open naturally when ripe. The species composing the genus Raphiolepis, the Indian Hawthorn, have been separated from CratÆgus; chiefly on account of the covering which encloses the seeds being of a paper-like texture, instead of bony, and each cell containing two seeds. The limb of the calyx also falls off before the fruit is ripe, instead of remaining on to form what is called an eye, as it does in the common Hawthorn. The leaves of the plants belonging to this genus vary in the different species; but those of the common Hawthorn are wedge-shaped, and cut deeply into three or five lobes.

The different species which compose the genus CratÆgus were formerly considered to belong to the genus Mespilus. This genus, which is now almost confined to the common Medlar (Mespilus germanica), agrees with CratÆgus in having each seed enclosed in a bony covering, but it differs in the limb of the calyx being in large leafy segments; and in the disk being very large and visible even when the fruit is ripe, from the tubular part of the calyx not closing over it.

Among the plants formerly included in the genus Mespilus, may be mentioned Photinia serrulata, and Eriobotrya japonica, both natives of Japan. The first of these was once called CratÆgus glabra, and it is remarkable for its beautiful glossy leaves, which are of a deep green when old, and beautifully tinged with red when young; the flowers are white, and they are produced in what botanists call corymbose panicles. There are some other species of the genus Photinia, but only two or three are common in British gardens. Eriobotrya japonica, the Loquat-tree, was formerly called Mespilus japonica. It is remarkable for its large and handsome leaves, which are woolly on the under side. The flowers, which are small and white, are produced in large panicles, and they are followed by large pendulous bunches of the yellow pear-shaped fruit, which is covered with a woolly substance, and hence the botanic name Eriobotrya, which signifies woolly grapes. The tree will stand out in the open air in England, and it will flower freely in a greenhouse, but it requires a stove to ripen its fruit.

Cotoneaster and Amelanchier were also formerly included in Mespilus, and they are very closely allied to Photinia and Eriobotrya. The species belonging to Photinia, however, are easily known by their shining leaves, and the petals of their flowers being reflexed, that is, curved back; and the species of Eriobotrya are distinguished by their woolliness, which spreads over even the flowers and fruit. The Cotoneasters are known by the small petals of their flowers, which curve inwards, and remain a long time without falling. The leaves are also thick, and woolly or clothed with rusty hair on the under side; and the flowers, which are produced in cymes or panicles, with woolly pedicels, are followed by bright red haws, resembling those of the hawthorn. Lastly, the genus Amelanchier is known by its long narrow petals, and its ovary having five or ten cells, with five styles united at the base.

TRIBE VI.—SANGUISORBEÆ.

The plants included in this tribe agree more or less with the common Burnet (Sanguisorba officinalis). This plant, which is found in great abundance in rich meadows on calcareous soils, has its flowers produced in a close terminal spike. The flowers have no petals, but the calyx, which is four-cleft, is pink, and there are four glossy brown bracts to each flower; so that, on the whole, the flowers are rather ornamental, notwithstanding their want of petals. There are only four stamens, and two carpels with slender styles and pointed stigmas. The leaves are pinnate, consisting generally of nine leaflets, and each pair of leaflets is furnished with two stipules. The Alchemilla, or Ladies’ Mantle, is nearly allied to the Burnet; but the flowers are in small corymbs, instead of spikes. The flowers have no petals; but the limb of the calyx is coloured, and divided into eight unequal segments. There are generally four stamens and only one style, though sometimes there are two. The ovary contains one or two carpels, each containing a single seed, and these when ripe are enclosed in a capsule, formed by the tubular part of the calyx becoming hardened. The leaves are lobed, plaited, and serrated at the margin; and those of the Alpine species (A. alpina), which is often found wild on the Scotch mountains, are covered with a beautiful silky substance of the most brilliant whiteness.