Fig. 17.—The Bi-pinnate leaf of an Acacia.Fig. 17.—The Bi-pinnate leaf of an Acacia.
Fig. 17.—The Bi-pinnate leaf of an Acacia.
The rest of the plant ofAcacia armatais very curious; what appear to be the leaves (seedinfig.15) are, in fact, only the petioles of the leaves dilated into what are called phyllodia; the true leaves, which were of the kind called bi-pinnate, having fallen off, or never unfolded. The true leaves, however, often appear on seedling plants; and thus, when seeds are sownof several kinds of Acacia, it is sometimes difficult to recognise them till they have attained a considerable age. The stipules of the leaves, (which are to ordinary leaves what bracts are to flowers,) are inAcacia armata, converted into spines, as shown ate. In some kinds of Acacia the true leaves, with the petioles in their natural state, (seefig.17,) are retained in the adult plants, as inAcacia dealbàta; and in others, the bi-pinnate leaves are occasionally found attached to the phyllodia, as inA. melanoxylon. The bi-pinnate leaves are composed of from six to twenty pairs of pinnæ, or compound leaflets (seefinfig.17), each of which consists of from eight to forty pairs of small leaflets (g). The Gum Arabic tree,Acacia vera, has leaves with only two pairs of pinnæ, but each has eight or ten pairs of small leaflets. The branches and spines are red, and the heads of flowers are yellow.There are above three hundred known species of Acacia.
The genus Mimosa differs from Acacia in the corolla being funnel-shaped, and four or five cleft. There are seldom above fifteen stamens, which are generally on longer filaments than those of the Acacia; and the legume is compressed and jointed or articulated between the seeds, so that the part which contains one seed may be broken off, without tearing the rest. The Sensitive-plant (Mimosa pudica) is a familiar example of this genus.
The cotyledons of the plants belonging to this tribe are generally leafy; and the seeds are not eatable. The plants themselves are easily recognised by their ball or tassel-shaped heads or spikes of flowers; by the small cup-shape and inconspicuous corolla of each; by the great number and length of the stamens; and by their bi-pinnate leaves, or phyllodia supplying the place of leaves—though the phyllodia are sometimes found in Australian plants with papilionaceous flowers, as, for example, inBossiæa ensata.
TRIBE III.—CÆSALPINEÆ.
Fig. 18.—Flower of the Barbadoes Flower-fence.Fig. 18.—Flower of the Barbadoes Flower-fence.
Fig. 18.—Flower of the Barbadoes Flower-fence.
Theflowers of the plants contained in this tribe have generally five regular, widely spreading petals, which are never joined together;and stamens of unequal length, which with few exceptions are also perfectly free. The petals are generally of the same size and shape; though sometimes, as in the Barbadoes Flower-fence (Poinciana, orCæsalpinia pulcherrima), four are of the same shape, and one deformed (seefig. 18). The filaments of some of the stamens are very long and curving over, but the others are much shorter and erect; the style is long and slender, ending in a pointed stigma. The legume is flat, and it looks almost many-celled, from the seeds being divided from each other by a kind of spongy substance, frequently found in the podsof plants belonging to this division. The leaves are bi-pinnate, and the stem is spiny.
The Carob-tree, or St. John’s bread (Ceratonia siliqua), agrees with the Barbadoes Flower-fence in the pulpy matter dividing the seeds, though it differs widely in its flowers, which are without petals, and do not possess any beauty. The pulp of the pods of the Carob tree is eatable; but that of Poinciana is said to be injurious. The pod of the Tamarind (Tamarindus indica) differs from the preceding species in having the pulpy matter of its pods contained between the outer and inner skin of each valve, like the fleshy substance in the pod of the pea, instead of serving as a bed for the seeds. The flowers of the tamarind have five equal petals of a brownish yellow, three of them being streaked with pink; and the anthers are nearly rose-colour. The stamens and the style both curve upwards. It is the pods prepared with sugar that form what we call Tamarinds. InCassia lanceolata, the leaves of which furnish senna, the flowers have a bright yellow corolla of five concave petals, three of which are somewhat larger than the others. The stamens are also unequal in length; and the style curves upwards. The legume is kidney-shaped, and the cells are divided from each other by thin membraneous partitions. The Gleditschia or Honey Locusts,now so frequently planted in our shrubberies on account of the lightness and elegance of their foliage, belong to this division, and some of them, particularly the Chinese Thorny Acacia (Gleditschia horrida), are remarkable for their thorns proceeding from the trunk and large branches, as well as from the axils of the leaves. The Logwood (Hæmatoxylon Campechianum), has inconspicuous yellow flowers, the petals being very little longer than the calyx; and the legume has seldom more than two seeds. Though it is considered a tree, the stem is seldom thicker than the arm of a man, and it is generally crooked; chips of the wood are used for dyeing purple. The Judas-tree (Cercis siliquastrum) is another species belonging to this division, as, though the flowers appear of the papilionaceous kind, they are, in fact, composed of five petals, nearly equal in size, but having the wings the largest. There are ten stamens, free, and of unequal length. The legume is oblong and many-seeded; and it opens only on the dorsal suture, the other side to which the seeds are attached being slightly winged. The flowers are each on a separate flower-stalk or pedicel, but they rise from the trunk and branches in tufts or fascicles. The leaves are simple and cordate; and they do not appear till the flowers have faded.
The Kentucky Coffee-tree (Gymnocladus canadensis) is the last plant belonging to this division that I shall attempt to describe. This tree is called in Canada, Chicot, or the stump-tree, from its having no visible buds, and thus appearing like a dead stump in winter. The flowers of this plant are white, and they are produced in racemes, but they bear no resemblance to the pea flowers, having rather a star-like appearance, like those of the Jasmine (seefig.19).Fig. 19.—Flowers of the Kentucky Coffee-tree.Fig. 19.—Flowers of the Kentucky Coffee-tree.The calyx (a) is tubular; and the upper part or limb is divided into five parts (b), which alternate with the petals of the corolla (c). There are ten stamens, but they are completely enclosed in the tube of the calyx. The pod is very large, the valves becoming hard and bony when dry; and the seeds are like large beans, the pod being deeply indented between the seeds. The leaves are bi-pinnate, with from four to seven pairs of pinnæ; the lower having only one small leaflet, but the rest bearing from six to eight pairs of leaflets each. This tree must not be confounded with the true Coffee-tree, which belongs to Rubiaceæ, and from which it isperfectly distinct in every respect; and it only takes its American name from its beans having been used as a substitute for coffee. The outer bark of this tree, when it becomes old, splits off in narrow strips and rolls up; and its timber, like that of the Robinia or False Acacia, having very little sap wood, is thus very strong in quite young trees, though it is of little value when the tree is full-grown.
The species contained in the first and second divisions of this order will be easily recognised by botanical students; and though those of the third division are much more difficult to find out, still there is a kind of family likeness, particularly in the leaves, which will enable the eye, with a little practice, to recognise them. The student should visit the hothouses of botanic gardens and nurseries, and should there endeavour to pick out plants belonging to this order.
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.
Allthe 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. Thesecharacters 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.
Fig. 20.—Rosa Fosteri.Fig. 20.—Rosa Fosteri.
Fig. 20.—Rosa Fosteri.
Theflowers 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. InRosa Fosteri, (seefig.20,) andits 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 inRosa cinnamoneaand 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 atb. 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 (seefig.21). The pitcher-shaped part of the calyx when the corolla falls becomes the hip (fig.20c), 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 (seefig.20d, andfig.21a,) and each contains only one seed which it does not open naturally to discharge: hence, the seeds of roses when sownare a long time before they come up.Fig.22 is the ripe fruit ofRosa cinnamonea, cut in two toFig. 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 (seefig.20e); 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 atg. 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.RosaandLowea, the latter containing only what was formerly calledRosa 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.
Theplants 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 anyother. 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 theFig. 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 (ainfigure23); 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 atc, and magnified atd, 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 ate; 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 atf. 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 atg. 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., agreewith 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 mentionedGeum Avens, orHerb Bennet, the carpels of which have each a hooked style;Sieversiaseparated from Geum, because the carpels end in a straight feathery awn; andTormentilla, 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.
Theonly genera in this tribe which contain well-known plants are Spiræa and Kerria. In Spiræa the calyx is five-cleft (seeainfig.24) and lined with the dilated receptacle, forming a shallow tube or rather cup for the reception of the carpels. There are five small roundishpetals (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 (seee). 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 toS. salicifoliaor Bridewort, Queen’s needle-work, &c. The flowers of this species are in spicate racemes, but others are in corymbs, as inS. bella; or in panicles, as inS. ariæfolia.
Fig. 24.—Flower of the Spiræa.Fig. 24.—Flower of the Spiræa.
Fig. 24.—Flower of the Spiræa.
Kerria is a genus containing only one species, the plant which was formerly calledCorchorus 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 witha 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.
Thistribe is distinguished by the fruit, which is what botanists call a drupe, that is, a stone fruit. The principal genera included in this tribe areAmygdalus, the Almond;Persica, the Peach and Nectarine;Armeniaca, the Apricot;Prunus, the Plum; andCerasus, 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 upperpart 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 ofwhich 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.
Fig. 25.—Flowers and fruit of the Sloe.Fig. 25.—Flowers and fruit of the Sloe.
Fig. 25.—Flowers and fruit of the Sloe.
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 ofPrunus domestica. The flowers in both are solitary (seefig.25), and consist of a five-toothed calyx (a) which is united at the base, and in the lining of which thestamens 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 fascicledFig. 26.—Flowers and stone of the Cherry.umbel (seea) infig. 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 (seef); 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.
Thecommon 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 considerable resemblance to the flowers of the genera already described, but the petals (seeain fig. 27) are oblong, rather than roundish.
Fig. 27.—Fruit and part of the Flower of the Apple.
Fig. 27.—Fruit and part of the Flower of the Apple.
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, placedside 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.
Fig. 28.—Fruit and part of the Flower of the Pear.
Fig. 28.—Fruit and part of the Flower of the Pear.
The Pear (Pyrus communis) differs from the apple in the shape of the fruit (seeainfig. 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 columnas 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 ofMalus. 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.
Fig. 29.—Flower and fruit of the Mountain Ash.
Fig. 29.—Flower and fruit of the Mountain Ash.
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 infig.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 atc; 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 calledPyrus arbutifolia, which has been successively included in the genera Cratægus, Aronia, and Mespilus; andP. 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 calledPyrus 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 (seea,fig.30), but theFig. 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 asin 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 genusCratægus 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 mentionedPhotinia serrulata, andEriobotrya japonica, both natives of Japan. The first of these was once calledCratægus 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 calledMespilus 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 witha 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.
Theplants included in this tribe agree more or less with the common Burnet (Sanguisorbaofficinalis). 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.
THE ORDER ONAGRACEÆ: ILLUSTRATED BY THE DIFFERENT KINDS OF FUCHSIA; ŒNOTHERA, OR THE EVENING TREE-PRIMROSE; GODETIA; EPILOBIUM, OR THE FRENCH WILLOW-HERB; AND CLARKIA.
Thetype of this order is considered to be the common evening Tree-primrose (Œnothera biennis), and it takes its name fromOnagra, the name given by Tournefort to the genus. The Fuchsia seems so unlike the Œnothera, that it appears difficult to any but a botanist to trace the connexion between them; but, botanically, they agree in the position of the ovary, which in both is so placed as to seem rather to belong to the flower-stalk than to the flower; and this peculiarity is found in all the genera included in the order. The parts of the flowers are also always either two, four, eight, or twelve; as, for example, there are four petals and eight stamens in both the Fuchsia and the Œnothera.
THE GENUS FUCHSIA.
Littlemore than fifty years ago, the first Fuchsia was introduced into England; and we are told that small plants of it were sold ata guinea each. Now more than twenty species, and innumerable hybrids and varieties, are in common cultivation, and we find them not only in greenhouses and windows, but planted in the open air as common border shrubs. The first Fuchsia seen in England wasF. coccinea, introduced in 1788; and this species is still common in our gardens. It was followed about 1796 byF. lycoides; and after that no other species was introduced till 1821, since when a full tide of Fuchsias has kept pouring in upon our gardens, from the different parts of Mexico, South America, and New Zealand, to the present time.
All the Fuchsias were formerly divided into two sections; the plants in one of which having the stamens and pistil concealed, and those in the other having the stamens and style exserted, that is, projecting beyond the other parts of the flower. The first division comprises all the small-flowered kinds; such asF. microphylla,thymifolia,cylindracea, andbacillaris, all which have the lobes of the calyx short, and the petals partially concealed.F. parviflorabelongs to this division, but it is distinguished by its glaucous leaves with an entire margin; andF. lycoidesis also included in it; though this last seems to form the connecting link between the two sections, as both its petals and its style and stamens are partially exposed. The second divisioncomprises all the kinds which have long projecting stamens.
As the general arrangement of the parts of the flower is nearly the same in both divisions,fig.31, which represents the section of a flower ofF. cylindracea, from theBotanical Register, will give my readers a clear idea of the botanical construction of the Fuchsia. In this figure,ashows two cells of the ovary (which when entireFig. 31.—Section of the flower of Fuchsia cylindracea.is four-celled, opening when ripe into four valves), with the seeds attached to a central placenta. This ovary is surrounded and protected by the dilated disk, which also serves as a lining to the tubular part of the calyx,b. The anthers, in this division, have very short filaments, which are inserted in the lining of the calyx, as shown atc;dis the style, which, in fact, consists of four styles united together, and which divides near the apex into four stigmas;e eare two of the four lobes of the calyx; andfis one of the four petals.
In the second division, of whichF. coccineamay be considered the type, the calyx and the corolla are of different colours. Infig.32, which shows a flower ofF. discolor, the Port Famine Fuchsia, the calyx (a) is scarlet and the most ornamental part of the flower, while the petals (b) are purple, and wrapped over eachFig. 32.—Fuchsia discolor.other. The ovary (c) is green, and when the petals and calyx fall off, it swells into a berry, which becomes of a dark purple when ripe.F. globosadiffers fromF. coccineain the flowers being shorter and more globose, while the limb of the calyx curves inward. InF. macrostemma, a well-known Fuchsia, the lobes of the limb of the calyx are, on the contrary, recurved, that is, turned backwards. This formation is common, more or less, to several other species. InF. excorticata, the New Zealand Fuchsia, there is a large fleshy knot at the base of the calyx, and strong ribs running up the lobes; the calyx is green when young, but it afterwards becomes crimson; and the petals are very small. This species is so different from the others, that it was at first described as a new genus, under the name of Skinnera. Thecalyx is green at first, but it afterwards becomes crimson.F. arboreahas pale-purplish flowers, and, likeF. lycoides, forms a connecting link between the two sections, the stamens being only a little exserted, and the petals hidden.
F. radicans, the only Fuchsia yet discovered with a creeping stem, which was introduced in 1841, belongs to this division.
These sections include all the Fuchsias known in British gardens previously to 1835; but since that period, two kinds have been introduced, which belong to a third division. These areF. fulgensandF. corymbiflora. In these plants the tube of the calyx is about two inches long, and the lobes are very short. The petals are also short, and scarlet or deep-rose colour, though not exactly of the same hue as the calyx. The leaves are large, with the midribs and veins red; and the branches and pedicels are also of a dark reddish purple.
THE GENUS ŒNOTHERA.
Inthe description of the botanical construction of the Fuchsia, my readers may have observed, that the ovary is placed below the calyx, and quite distinct from it. The same construction is still more visible in the Œnothera, as the tube of the calyx is very slender, and often more than two inches long, while the ovary is often vase-shaped, and of large size. The calyx ofŒnothera biennis, the common Evening or Tree Primrose, consists of four sepals growing together in the lower part, so as to form a long tube (ainfig.33), and with the upper part or limb generally in two segments (b), which are bent quite back when the corolla expands, and which may be easily divided with a pin into four. There are four petals in the corolla (c), and they are placed so as to wrap over each other at the base. The calyx is lined with the dilated receptacle, and in this lining are inserted the filaments of the eight stamens (as shown atd); the stamenshaving versatile anthers, that is, anthers attached to the filament by the middle, so as to quiver at every breath. The pollen contained in the cells of these anthers feels clammy when touched; and its particles, when magnified, will be found to be triangular, and connected by small threads, a form of construction peculiar to this genus and its allies. The style is long, and the stigma is four-cleft. The ovary (e e) is situated at the base of the calyx, and when ripe, it becomes a four-celled dry capsule, which bursts into four valves, opening at top to discharge the seed. The seeds, when young, are attached to the central placenta, and they are quite free from hair or wool of any kind.