CHAPTER V.

Fig. 33.—The Evening Primrose(Œnothera biennis).

The genus Œnothera being a very extensive one, it has been divided by M. Spach, a German botanist residing in Paris, into fourteen new genera; but only one, or at most two, of these genera have been adopted by other botanists. One of these Godetia, which embraces all the purple-flowered kinds, has been divided from Œnothera, on account of a slight feathery appearance on the seeds; whereas the seeds of the true yellow-flowered Œnotheras are naked, that is, without the slightest appearance of any feathery substance or wing. The other genus, BoisduvaliaSpach, includes only two species, both with pink flowers, which are very seldomseen in British gardens. The generic mark of distinction consists in four of the stamens in these species being shorter than the other four; whereas in the true Œnotheras all the eight stamens are of equal length. As M. Spach’s other genera have not been adopted by any British botanist, it is not worth while troubling my readers with the distinctions between them. The flowers of the yellow Œnotheras only open in the evening, or in cloudy weather; but those of the purple kinds, or Godetias, remain open all day. The leaves in both kinds are alternate.

THE GENUS EPILOBIUM.

Fig. 34.—Epilobium roseum.Thisgenus is well known, by the showy plant often seen in shrubberies, called the French Willow-Herb—(Epilobium angustifolium), and the English weed called Codlings-and-Cream (E. hirsutum). In this genus, the tubular part of the calyx which incloses the ovary, is quadrangular, asshown atainfig.34, which represents seed-vessels ofEpilobium roseum, a very common weed in the neighbourhood of London. The limb of the calyx is four-cleft, and the corolla has four petals; and when these fall off, the ovary assumes the appearance shown ata. The quadrangular form is retained by the capsule, which, when it ripens, bursts open into the four valves (b), and discharges the seed which was attached to the central placenta (c); each seed being furnished with a little feathery tuft resembling pappus, as shownFig. 35.—Seed of Epilobium.infig.35. The genus Epilobium is divided into two sections; the plants in one of which have irregular petals, the stamens bent, and the stigma divided into four lobes, as in the French Willow-Herb, and the other showy species; and the plants in the other section having small flowers with regular petals, erect stamens, and the stigma undivided.

THE GENUS CLARKIA.

Thecalyx in this genus is tubular, with the limb in two or four lobes, as in Œnothera. The corolla is, however, very different, the four petals being unguiculate or clawed; that is, so much narrower in the lower part as to stand widely apart from each other; they are also threelobed. The stamens are very different, only four of them being perfect, and the anthers of the other four being wasted and destitute of pollen; and the stigma is divided into four leaf-like lobes, very different from those of all the other genera included in the order. The capsule is cylindrical in shape, and furrowed on the outside; it is four-celled, and when ripe, it bursts open by four valves. The seeds are quite naked.

Among the other genera belonging to this order, I may mention the following:Gaura, the petals of which are somewhat unguiculate, like those of Clarkia, but not three-lobed as in that genus; the segments of the limb of the calyx often adhere two together, so as to appear three instead of four; the ovary is one-celled, and the seeds naked:Lopezia, which has apparently five irregular petals, though, on examination, one will be found to be a metamorphosed stamen, a four-cleft calyx, two stamens, including the one converted into a petal, and a globular, four-celled capsule: andCircæa, or Enchanter’s Nightshade, which has the limb of the calyx apparently in only two segments, and only two petals and two stamens; the capsule is globular like that ofLopezia, but it is covered with very small hooked bristles, and it is divided into only two cells, each containing only one seed.

THE ORDER RUBIACEÆ: ILLUSTRATED BY THE CINCHONA, OR PERUVIAN BARK; LUCULIA GRATISSIMA; CAPE JASMINE; RONDELETIA; COFFEE; IXORA; IPECACUANHA; MADDER; GALIUM; WOODRUFF; AND CRUCINELLA STYLOSA.

Thisorder contains more than two hundred genera; but by far the greater part of these are composed of tropical plants, many of which are not yet introduced into Britain. Several of the genera, on the other hand, are British weeds; and this difference in habit, with others in the qualities of the plants, &c., have occasioned some botanists to divide the order into two: one of the new orders being called Cinchonaceæ, and containing the plants most resembling Cinchona; and the other Galiaceæ, containing the plants most nearly allied to Galium or Bedstraw.

The characteristics of Rubiaceæ, in its most extended sense, are that the ovary is surrounded by the calyx, and placed below the rest of the flower; and that the corolla has a long tube, lined with the dilated receptacle, in which the stamens are inserted. In most of the species, the filaments are very short, and the anthers nearly or entirely hidden in the corolla; and in many cases,the segments of the calyx remain on the ripe fruit, as they do in the genus Pyrus in Rosaceæ, where they form what is called the eye in the apple and pear.

The qualities of the Cinchona division of the Rubiaceæ are generally tonic; but some of the plants, as for example the Ipecacuanha, are used as emetics, and one (Randia dumetorum) is poisonous. The qualities of the Galium division are not so decidedly marked; but the roots of some of the plants are used for dyeing.

THE GENUS CINCHONA, AND ITS ALLIES.

Fig. 36.—Cinchona, Peruvian Bark (Cinchona Lanceolata).

Thewell-known medicine called Peruvian bark is produced by three species of the genus Cinchona; the pale bark, which is considered the best, being that ofC. lanceolata. The flowers of this species are small, and of a very pale pink. The calyx (seeain fig. 36) is bell-shaped, and five-toothed; and the corolla (b) is tubular, with the limb divided into five lobes, and silky within, as shown in the magnified section atc. The stamens (d) have very short filaments, which are inserted in the throat of the corolla. The ovary (e), which is deeply furrowed when young, is inclosed in the calyx; it is two-celled, with a single style, and a two-lobed stigma (f). The capsules retain the lobes of the calyx as a sort of crown (g); and they open naturally at thedivision between the two cells, as shown ath, beginning at the base. The cells (i) each contain several seeds.C. oblongifolia, which yields the red bark of the shops, has cream-coloured flowers, as large as those of a Jasmine, which they resemble in shape; andC. cordifolia, which produces the yellow bark, has flowers like the first species, and heart-shaped leaves. The singular plant calledHillia longiflora, is nearly allied to Cinchona; as is also the beautiful and delightfully fragrantLuculia gratissima. In this last plant the tube of the calyx is very short, and pear-shaped, and the segments of the limb are short, and sharply pointed. The corolla is salver-shaped, with a long tube, and a spreading, five-parted limb. The anthers are nearly sessile, and the short filaments to which they are attached are inserted in the throat of the corolla, only the tips of the anthers being visible. The stigma is divided into two fleshy lobes, and the capsule splits, not like that of Cinchona, but from the apex to the base in the centre of each cell. The seeds are very small, and each has a toothed, membranous wing. The flowers of this beautiful plant are produced in a large head, and at first sight greatly resemble those of a Hydrangea; but they are easily distinguished by their delightful fragrance.

Manettia cordifolia, a very pretty stove-twiner often seen in collections, is very nearly allied to Luculia, differing principally in the shape of the flowers, which in Manettia have a long tube and a very small limb.Bouvardia triphyllaand the other species of Bouvardia, andPinckneya pubescens, belong to this division; and such of my readers as have the living plants to refer to, will find it both interesting and instructive to dissect them and compare the parts of their flowers with the description I have given of Luculia and Cinchona, so as to discover the difference between the different genera; afterwards reading the generic character of each given in botanical works, that they may see how far they were right.

THE GENUS GARDENIA AND ITS ALLIES.

TheCape Jasmine (Gardenia radicans) is a well-known greenhouse plant, remarkable for the heavy fragrance of its large white flowers, which die off a pale yellow, or buff. The calyx has a ribbed tube, and the limb is parted into long awl-shaped segments. The corolla is salver-shaped, that is, it has a long tube and a spreading limb, the limb being twisted in the bud. There are from five to nine anthers, having very short filaments which are inserted in the throat of the corolla. The stigma is divided into two erect fleshy lobes. The ovary is one-celled, but there are some traces of membranes, which would, if perfect, have divided it into from two to five cells. The seeds are numerous and very small.Gardenia radicansis a dwarf plant, which flowers freely when of very small size, and is easily propagated from the readiness with which its stem throws out roots; butG. floridais a shrub five or six feet high, and much more difficult to cultivate. In both species the flowers are generally double, and the petals are of a fleshy substance, which gives the corolla a peculiarly wax-like appearance.

There are many other species, but the two above-mentioned are the most common in British gardens.Burchellia capensisis generally considered to belong to this division of Rubiaceæ, though its flowers bear more resemblance to those of Cinchona; and the singular plant calledMussæuda pubescens, the flowers of which are small and yellow, but the bracts are so large and so brilliantly white as to look like flowers;Posoqueria versicolor, an ornamental plant lately introduced, belong to this division.

THE GENUS RONDELETIA AND ITS ALLIES.

Rondeletia odorata, sometimes calledR. coccinea, and sometimesR. speciosa, is a veryFig. 37.—Section of the flower of Rondeletia.fragrant stove shrub, a native of Cuba. The flowers are produced in corymbs, and their botanical construction is shown in the magnified sectionfig.37. In thisais the ovary inclosed in a hairy calyx;bshows the limb of the calyx cut into awl-shaped segments;cshows the manner in which the very short filaments of the anthers are inserted in the throat of the corolla;dshows the termination of the dilated receptacle which lines the tube of the corolla; andethe segments of thelimb. I have given the section of this flower, that my readers may compare it with the section of the flower of the Cinchona infig.36,Fig. 38.—Part of the head of flowers of Rondeletia.in p. 87, and may see the general resemblance which connects the two plants in the same order, and the differences which mark them to be of different genera.Fig.38 is a tuft of flowers ofRondeletia odorata.Wendlandiais nearly allied to Rondeletia; as is the magnificentPortlandia grandiflora, which somewhat resemblesBrugmansia luteain shape though not in colour, as its flowers are white.

THE GENUS COFFEA AND ITS ALLIES.

TheCoffee-tree (Coffea arabica) differs from the other Rubiaceæ in the tube of its calyx being very short and disappearing when the ovary begins to swell; and in the filaments of the stamens being sufficiently long to allow the anthers to be seen above the throat of the corolla (seeainfig.39). The limb of the corolla (b) is five-cleft, and the style (c) bifid. Each ovary when its flower falls, becomes distended into a berry (d) or rather drupe, containing the nute, in which are two seeds, flaton one side, and convex on the other, which are placed with the flat sides together, as shown atf; each seed having a deep longitudinal groove, as shown atg. These seeds are our coffee.

Fig. 39.—Coffee.(Coffea Arabica.)

The flowers ofIxora coccineahave the same general construction as those of the other plants of the order. The calyx has an ovate tube, and a very small four-toothed limb; and the corolla is salver-shaped, with a long and very slender tube, and a four-parted spreading limb. There are four anthers inserted in the throat of the tube of the corolla, and just appearing beyond it, and rising a little above them is the point of the style with its two-cleft stigma. The berryis two-celled, but it differs from that of the coffee in retaining the lobes of the calyx, which form a sort of crown. There are many kinds of Ixora, all stove shrubs, and all conspicuous for their large heads or rather corymbs of showy flowers. The genus Pavetta has been divided from Ixora, principally because the species composing it have the style projecting considerably beyond the corolla, instead of only just appearing above it.

The drug called Ipecacuanha is the produce of two plants belonging to this order,Cephælis IpecacuanhaandRichardsonia scabra; though a spurious kind is made from the roots of three species of Viola, all natives of South America, and a still inferior one from the roots of a kind of Euphorbia, a native of Virginia and Carolina. It is important to know this, as the best kinds possess tonic properties as well as emetic ones, while the inferior kinds are only emetics, and they are very injurious if taken frequently. The best brown Ipecacuanha is the powdered root ofCephælis Ipecacuanha; a plant with small white flowers collected into a globose head, which is shrouded in an involucre closely resembling a common calyx. The true calyx to each separate flower is small and roundish, with a very short five-toothed limb. The corolla is funnel-shaped, with five small bluntish lobes.The anthers are inclosed in the corolla, and the stigma, which is two-cleft, projects only a little beyond them. The berries are two-celled and two-seeded, and they retain the lobes of the calyx. The root is fleshy and creeping.Richardsonia scabra, which produces the white Ipecacuanha, has its flowers also in heads, but the calyx is larger in proportion to the corolla, and the stamens and style are both visible. The capsule contains three or four one-seeded nuts, crowned by the calyx; which, however, becomes loosened at the base, and falls off, before the seeds are quite ripe. Cephalanthus, Spermacoce, and Crusea, are nearly allied to Richardsonia.

The above plants all agree, more or less, with Cinchona, in their qualities, and they are all included by Dr. Lindley in the order Cinchonaceæ.

THE GENUS GALIUM AND ITS ALLIES.

Thecommon Bedstraw (Galium vernum) is a British weed, common in dry fields and on little knolls, which produces its cluster of bright yellow flowers in July and August. The flowers are so small that it is difficult to examine them in detail, but, by the aid of a microscope, the ovary will be found to be inclosed in the tube of the calyx as in the other Rubiaceæ,though the calyx has hardly any limb. The corolla is what is called rotate or wheel-shaped, and its limb is divided into four segments. There are four short stamens, with their filaments inserted in the throat of the corolla, and two very short styles. The fruit is a dry capsule inclosing two seeds. Thus far the construction of the plant agrees with the other Rubiaceæ, but the stem is square, and the leaves are different, for they are without footstalks, and are disposed in what is called a whorl (seefig.40). TheFig. 40.—Whorl of leaves of Bedstraw.(Galium vernum.)whorl, however, according to Professor De Candolle, does not consist entirely of leaves; but of two opposite leaves and two or more stipules, which are so like the leaves as scarcely to be distinguished from them, though upon close examination, it will be found that the leaves have buds in their axils (that is between them and the stem), which the stipules have not. This theory is not adopted by Dr. Lindley, who considers the whorl to consist entirely of leaves, and to be one of the distinctive marks of his order Galiaceæ.

All the plants in this division of Rubiaceæagree with the common Bedstraw (Galium vernum) in the formation of their leaves and stem; but the species of Galium are distinguished by the margins of the leaves and the principal veins, in nearly all the species, being covered with prickles, which in some cases point forwards, and in others are bent back, so as to catch everything they touch. This is particularly the case with the leaves of the plant called Goose-grass, or Cleavers (Galium aparine); and its fruit is covered with hooked bristles, which take so firm a hold as to make it difficult to separate them from anything they have caught hold of. The pretty little weed called Field Madder (Sherardia arvensis), the fragrant Woodruff, (Asperula odorata), andRubia peregrina, the only British species of Madder, all agree with Galium in its more important characters; and as they are all common weeds, my readers will probably find it interesting to trace the differences between them. Galium and Rubia agree in having scarcely any limb to the calyx, and a rotate corolla; but the limb, which is only four-parted, or even three-parted, in Galium, has always five lobes in Rubia; there are also five stamens in Rubia, and the fruit is a berry; whereas there are only four stamens in Galium, and the fruit is dry. Sherardia agrees with Asperula in having a funnel-shaped corolla with a four-cleft limb; but in Sherardia the limb of the calyx remains on as a crown to the fruit, while in Asperula it drops off. In Sherardia there is only one style with a two-lobed stigma; and in Asperula there are two styles united at the base.

There is a very pretty plant calledCrucinella stylosa, which has lately been much cultivated in gardens, and which belongs to this order. This plant has large heads of pretty pink flowers, each of which has a funnel-shaped corolla, with a long tube concealing the anthers, but beyond which the style projects so far as to give rise to the specific name ofstylosa. The stigma in this plant is clavate, that is, club-shaped, and it is cleft in two, though the lobes are not spreading.

THE ORDER COMPOSITÆ: ILLUSTRATED BY THE SUCCORY, THE SOWTHISTLE, THE DANDELION, THE BURDOCK, THE DAISY, THE CHRYSANTHEMUM, FEVERFEW, PELLITORY OF SPAIN, WILD CHAMOMILE, TRUE CHAMOMILE, YARROW, THE BUR-MARIGOLD, GROUNDSEL, RAGWORT, BIRD’s TONGUE, PURPLE JACOBÆA, CINERARIA, SUNFLOWER, MUTISIA, AND TRIPTILION.

Theplants composing the order Compositæ have all compound flowers, which differ from other flowers as much as a compound leaf does from a simple one. As the compound leaf is composed of a number of leaflets or pinnæ united by a common petiole; so a compound flower is composed of a number of florets, united by a common receptacle, which is surrounded by a calyx-like involucre, so as to give the whole mass the appearance of a simple flower. Each floret has a calyx, the tubular part of which is rarely sufficiently distinct to be perceptible, but the limb is generally cut into long feathery segments called pappus. The ovary of each floret contains only one seed; and the fruit, which is called an achenium, retains the pappus when ripe, and falls without opening. There are five stamens, the filaments of which are distinct, but the anthers grow together so as toform a kind of cylinder, through which passes the style, ending in a two-lobed stigma (seeainfig.41). Most of the corollas are of twoFig. 41.—Ligulate floret of wild Lettuce.kinds: viz. the ligulate, as exemplified in the floret of the wild Lettuce (Lactuca virosa) shown infig.41; and the tubular, as shown in a floret of the Cotton-thistle (Onopordium Acanthium) seefig.42. All the British species of Compositæ have their florets either entirely of one of these kinds, or of the two mixed together; but some foreign genera have florets with two equal lips, cutFig. 42.—Tubular floret of the Cotton-thistle.into three or four lobes, as shown in a floret ofMutisia latifolia, at (e),fig.46, p. 108. These florets are called bilabiate. It will be observed that in all these examples, as indeed, in all the flowers belonging to the order, that the pappus (b, infigs.41 and 42), is always on the outside of the corolla, thus plainly indicating its connexion with the calyx.

The order Compositæ is a very large one, above seven thousand species having beennamed and described; and to assist the memory in retaining the names of this great number of plants, various means have been devised for dividing the order into sections and tribes. The principal botanists who have proposed means of arranging this order, are Cassini, Lessing, and lastly the late Professor De Candolle, in three volumes of hisProdromuspublished in 1840. But as the distinctions between the divisions proposed, lie in the difference found in the stigmas and pappus of the different genera, I have judged them too troublesome for my readers, as I am sure they are for myself, and I have preferred following the plan adopted by Dr. Lindley in hisElements of Botany, published in 1841, and dividing the Compositæ into four tribes; viz., the three originally proposed by Jussieu, and a fourth added by Professor De Candolle, containing the plants with bilabiate florets, which were either not known, or overlooked, by Jussieu. It may perhaps be necessary to add, that this arrangement forms the basis of the new one proposed by De Candolle, and that the principal difference consists in the subdivisions.

TRIBE I.—CICHORACEÆ.

Florets ligulate. Juice milky, narcotic.

Fig. 43.—Sowthistle.(Sonchus oleraceus.)

Theplants contained in this tribe bear more or less resemblance to the common Succory (Cichorium Intybus). This beautiful plant, which is found in great abundance wild in many of the sandy and chalky districts of England, has large bright blue flowers, which when examined will be found to consist of a number of florets, all of the kind called ligulate, that is somewhat like a cornet of paper; the upper part being broad and flat, and serrated at the edge. The pappus in this genus is very short, and it is scaly rather than feathery. The leaves are bitter, and when broken give out a milky juice; and the fleshy roots when roasted are used to adulterate coffee. The Endive is a variety of this species, or another species of the same genus. The Sowthistle (Sonchus oleraceus) abounds in the same milky juice as the succory, and has the same kind of fleshy root. The flower is composed of a scaly involucre (shown atainfig.43) and a number of ligulate florets (seeb), which when they fall show the pappus (c), forming a feathery ball. The manner in which the pappus is attached to the seed-vessel is shown at (d); and the receptacle after the florets have been pulled out, but with the involucre stillFig. 44.—Seed of the Dandelion.attached to it, at (e). A detached floret is shown at (f). The Dandelion (Leontodon Taraxacum) differs from the Sowthistle: in its florets, which are flatter and looser; in its receptacle, which is globular; and above all, in its pappus, which is what is called stipitate or stalked, that is, the tubular part of its calyx rises to a considerable height above the capsule, before it becomes divided into its feathery segments, as shown infig.44. The leaves of this plant are what is called runcinate, that is, the lobes into which they are cut point downwards towards the root instead of upwards from it, and the root is also fleshy. The Lettuce, Salsafy or Goat’s-beard, Ox-tongue, Hawkweed, Cat’s-ear, Nipplewort or Swine’s Succory, and many other well-known plants, belong to this tribe.

TRIBE II.—CYNAROCEPHALÆ.

Florets tubular. Juice watery, tonic.

Theplants in this division all bear more or less relation to the common Artichoke (Cynara Scolymus). The scales of the involucre are generally fleshy at the base, but terminate outwardly in a sharp hard point. The florets are tubular, and intermixed with them in the receptacle are frequently found the hardened bracts, which in this state are called paleæ, and which appear to be of a chaffy substance, as exemplified in the choke of the Artichoke, the fleshy receptacle being in this plant what we call the Artichoke bottom. This peculiar formation is shown more in detail infig.45, which representsFig. 45.—Part of the flower-head of the Burdock.part of the flower of the common Bur or Burdock (Arctium Lappa), so annoying from the strong hold it takes of any part of the dress which it may chance to touch. Infig.45ais the involucre, every scale in which is hooked and turned inwards, so as to hold firmly whatever it may catch;bis a floret showing its tubular shape, and its style proceeding through theunited anthers;cshows the hardened bracts or paleæ, the other florets having been removed; anddshows a fruit with a palea attached, magnified. All the different kinds of thistle belong to this division; and though many of the kinds have not the hardened bracts, they have all a spiny involucre. The pappus of the thistle is generally attached to a kind of disk, from which it becomes loosened soon after the seed falls, and this thistle, down, as it is called, being extremely light, is blown about by the winds. All the thistles have fleshy roots, and take firm hold of the soil. The Corn Blue-bottles (Centaurea), the Wild Saffron (Carthamus tinctoria), and many other well-known plants, belong to this division.

TRIBE III.—CORYMBIFERÆ.

Florets partly tubular and partly ligulate; juice watery; sometimes bitter and tonic, and sometimes acrid. The seeds of some of the species yield oil.

Theplants included in this tribe all bear more or less resemblance to the common Daisy. In this well-known flower, the white florets are all ligulate, and compose what is called the ray, and the yellow flowers, which are tubular, are called the disk. The involucre is simple and leafy, and the receptacle is conical. The seeds are without pappus. The Chrysanthemum isnearly allied to the Daisy, and its seeds also are destitute of pappus; but it is easily distinguished by its involucre, which is scaly, and by the flower forming a kind of depressed globe in the bud. The scales of the involucre are strongly marked, from being edged with a thin membrane, and the florets of the ray are much longer in proportion to those of the disk than in the Daisy. The great Ox-eye Daisy, which was formerly calledChrysanthemum leucanthemum, is now placed in a new genus, and calledLeucanthemum vulgare; and the Chinese Chrysanthemums have been removed to the genusPyrethrum. Both plants, however, will no doubt long continue to be called by their old names. The beautiful yellow-flowered plant often found growing among corn (Chrysanthemum segetum), the three-coloured Chrysanthemum (C. tricolororcarinatum), and the yellow annual Chrysanthemum (C. coronarium), with some others, have been left by Professor De Candolle in their old genus. In the Feverfew (Pyrethrum), the receptacle is elevated, and the fruit is crowned with a narrow membrane. The Pellitory of Spain was formerly considered to belong to this genus, and afterwards to the Chamomile, but it is now calledAnacyclus Pyrethrum.Matricaria Chamomilla, the wild Chamomile, has also no pappus; and in this plant the receptacle isalmost cylindrical. The true Chamomile (Anthemis nobilis) greatly resembles the Chrysanthemum in its flowers; but they are distinguished by having a chaffy receptacle, and the fruit having a membranous margin. The smell of the Chamomile is aromatic, and its qualities highly tonic. The Yarrow (Achillea millefolium) is another plant destitute of pappus, but with a chaffy receptacle; it is also remarkable for its leaves, which are doubly pinnatifid.

It will be seen by the above enumeration, that in many plants belonging to this division, the pappus is entirely wanting, and in others it will be found to assume a different form to that which it bears in the other tribes. Thus, in the Bur-Marigold (Bidens), the pappus consists of from two to five erect awns, which are covered with very small, bent bristles. The genus Senecio has soft, hairy pappus, as may be seen in the common Groundsel (S. vulgaris); the leaves of this weed are pinnatifid, and somewhat stem-clasping, and the flowers have no ray florets. In other species of this division, however, the ray florets are very conspicuous: as, for example, in the common yellow Ragwort (S. Jacobæa), in the great fen Ragwort, or Bird’s tongue (S. paludosa), and in the purple Jacobæa (S. elegans). Nearly allied to Senecio, is the genus Cineraria, so much, indeed, that Professor De Candolle,in his late arrangement of the Compositæ, has included the greater part of the species in Senecio. The greenhouse species, with purple flowers, are among those which have been changed; but they will probably always retain the appellation of Cineraria, as an arbitrary English name. The Asters, or Michaelmas Daisies, Golden Rod, Elecampane, Leopard’s Bane, the Cape Marigold, (now called Dimorphortheca, instead of being included in the genus Calendula), Coltsfoot, Wormwood, Southern-wood, Tansy, and many other well-known plants, belong to this division.

The Sunflower (Helianthemum annuus) is an example of one of the plants belonging to this division which has seeds yielding oil. In this plant the pappus is awl-shaped, and deciduous; and the receptacle, which is broad and somewhat convex, is paleaceous. The seeds are large and oblong, and when pressed, yield a considerable quantity of oil. The Madia is another oil plant; and indeed the seeds of several in this division yield oil.

TRIBE IV.—LABIATÆFLORÆ.

Florets bilabiate.

Theplants belonging to this division are rarely seen in British gardens; but when they do occur, they are well worth examining, fromthe singularity of their formation.Mutisialatifolia(see fig. 46) has a large, woolly involucre, theFig. 46.—Flower and Leaf of Mutisia Latifolia.scales of which are of two kinds, the outer ones, (a), being pointed and leaf-like, and the inner ones, (b), having the appearance of scaly bracts. The florets of the ray, (c), are narrow, and spreading in the fully expanded flower; and those of the disk, (d), are shorter, erect, divided into two lips, which curl back, and the lower one of which is again divided into two segments (as shown atein the detached floret). The leaves of this plant are very curious; the midrib is lengthened and drawn out into a tendril, as shown atf, and the petiole (g) is decurrent. There are several other genera belonging to this tribe, but none of them are particularly ornamental exceptTriptilion spinosum, which has flowers of the most brilliant blue, that do not lose the intensity of their colour in drying.

THE ORDER ERICACEÆ: ILLUSTRATED BY THE COMMON OR BESOM HEATH, THE MOOR HEATH, CAPE HEATHS, LING OR HEATHER, ANDROMEDA, LYONIA, ST. DABÆOC’S HEATH, ARBUTUS, THE BEARBERRY, GAULTHERIA, CLETHRA, RHODODENDRON, INDIAN OR CHINESE AZALEAS, YELLOW AZALEA, AMERICAN AZALEAS, RHODORAK, ALMIA, MENZIESIA, LOISELEURIA, LEDUM, LEIOPHYLLUM, THE BILBERRY, THE WHORTLE-BERRY, THE CRANBERRY, PYROLA, AND MONOTROPA.

Thename of Ericaceæ, which most people are aware signifies the Heath family, conjures up immediately the image of a number of narrow-leaved plants, with globular, ventricose, or bell-shaped flowers; and we are apt at first to think that the family is so natural a one, as to require very little explanation. Did the order include only the Heaths, this would be the case, for all the Heaths, different as they are in some particulars, may be recognised at a glance: but as the order includes the Rhododendrons, Azaleas, and Kalmias, besides several other plants which have not so strong a family likeness to each other as the Heaths, it becomes necessary to say a few words on the botanical resemblances which connect them together. The first, and most striking, of these is the shape of the anthers, each of which appears like twoanthers stuck together, and the manner of their opening, which is always by a pore or round hole, in the upper extremity of each cell. The filaments, also, in all the genera, except Vaccinum and Oxycoccus, grow from beneath the seed-vessel, being generally slightly attached to the base of the corolla. There is always a single style with an undivided stigma, though the capsule has generally four cells, each containing several of the seeds, which are small and numerous. The calyx is four or five cleft, and the corolla is tubular, with a larger or smaller limb, which is also four or five cleft. The order has been divided into four tribes, which I shall describe in this chapter, though some of these are considered as separate orders by Dr. Lindley and other botanists.

TRIBE I.—ERICEÆ.

Fig. 47.—The Besom Heath(Erica Tetralix).Thistribe, which comprehends all the heath-like plants, has been re-divided into two sub-tribes, one containing the genera most nearly allied to the heaths, and the other those belonging to the Andromeda. In both there is a honey-bearing disk under the ovary, and the leaves are generally rolled in at the margin, as shown at a, infig.47.

SUB-TRIBE I.—ERICEÆ NORMALES.

Allthe genera in this sub-tribe, twenty-two in number, were formerly included in the genus Erica; and some botanists still consider all the species to belong to that genus, with the exception of those included in Calluna, while others adopt about half the new genera. In this uncertainty, I shall only describe two of the doubtful genera, partly because the distinctions between them and the true heaths are strongly marked, and partly because the species they contain are frequently met with in British gardens and greenhouses, where they are sometimes labelled with their old names and sometimes with their new ones.

In the genus Erica, one of the commonest species is the Besom Heath (E. tetralix), which is found in great abundance on moorish or boggy ground in every part of Britain. In this plant, the corollas of the flowers appear each to consist of a single petal, forming an egg-shaped tube (seebinfig.47), contracted at the mouth, but afterwards spreading into a four-cleft limb, through which is seen projecting the style, withits flat stigma. The corolla is, however, really in four petals, which, though they adhere together, may be easily separated with a pin. The stamens are concealed by the corolla, but the manner in which they grow is shown atc; anddis a single stamen, showing the spurs or awns at the base of the anther, the position of which is one of the characteristics of the genus Erica in its present restricted form;eis a capsule with the style and stigma attached; andais a leaf showing its revolute or curled back margin. The leaves of this species are in whorls, four leaves in each whorl, and they are ciliated, that is, bordered with a fringe of fine hairs.

All the true Heaths bear more or less resemblance to this plant. In some, the corollas are bell-shaped, spreading out at the tip into five teeth, which inclose the stamens, as shown infig.48; and in others they are nearly globose swelling out near the calyx, and tapering to aFig. 48.—Bell-shaped Heath.Fig. 49.—Cape Heath.(E. hispida.)point, beyond which the stigma and anthers project; as in the Cape Heath, calledErica hispida, a flower of which is shown infig.49. The leaves also differ exceedingly, in the number contained in each whorl; as in some species there are only three in a whorl,while in others they are five or six. The general features of all the Heaths are, however, the same—viz., there are eight stamens, which are generally inclosed in the corolla, though they sometimes project beyond it, as shown infig.49, and the anthers of which are two-cleft, and awned or crested at the base, while the filaments are hair-like; one style, which always projects beyond the corolla, and has a flattened stigma; a four-parted calyx and corolla which is tubular, with a four-parted limb. There are nearly two hundred species of this genus, some of which are natives of Europe, and others of the Cape of Good Hope.

The moor Heaths (Gypsocallis) were separated from the genus Erica, by Mr. Salisbury, principally on account of the corolla being campanulate, or shortly tubular, with a dilated mouth; and the stamens projecting beyond the corolla. The filaments are also generally flat; the anthers are without awns, and distinctly in two parts; and the stigma is simple, and scarcely to be distinguished from the style. The common Cornish Heath (G. vagans), and the Mediterranean Heath (G. Mediterranea), are examples of this genus, which appears strongly marked, though, as I before mentioned, some botanists do not adopt it.

Callista is a genus established by the lateProfessor Don, which appears very distinct,Fig. 50.—Callista bucciniflora.though it also has not been generally adopted. It includes all those beautiful Cape Heaths which have a shining, glutinous, ventricose, or cylindrical corolla with a spreading limb (seeainfig.50), and a capitate stigma (b).C. buccinifloraandC. ventricosa, are examples of this genus.

The Ling or Heather, which Linnæus calledErica vulgaris, is now generally placed by all botanists in a separate genus called Calluna, which was established by Mr. Salisbury. The calyx of this plant is membranous, and coloured so as toFig. 51.—Stamen of the Ling.resemble a corolla, and it is furnished with four bracts at the base, which resemble a calyx. The true corolla is bell-shaped, and shorter than the calyx. The stamens are inclosed, and the anthers are of the very singular form shown infig.51. The stigma is capitate, and the flowers are disposed in what is called a racemose spike. The leaves are trigonal; they are very short, and they are laid over each other like scales in four rows. The Ling is the only species in the genus.

SUB-TRIBE II.—ANDROMEDEÆ.

Theplants in this sub-tribe differ decidedly from those of the preceding division, in having ten stamens, while all the genera of heaths have only eight. The calyx is also five-cleft instead of four; and the corolla, which falls before the seeds are ripe, has a five-lobed limb. The sub-tribe is divided into twenty genera, more than half of which are perfectly distinct.

The genus Andromeda is distinguished by its globose corolla which has a five-lobed limb; and its stamens which have their filaments bearded, and their anthers short and two-awned.Fig. 52.—Stamen of Andromeda.Fig.52 shows a stamen of the wild rosemary (Andromeda polifolia) with its bearded filament (a), and its two-awned anther with its pore-like openings (b). The cells of the capsule open in the middle, down the back, to discharge the seeds. Professor Don has divided the genus Andromeda into six genera; some of which contain only one or two species. Thus onlyAndromeda polifoliaandA. rosmarinifoliaare left in the genus Andromeda; Cassandra contains onlyA. calyculata, andA. angustifolia; and Zenobia, only the beautifulAndromeda speciosa. In Cassandra the anthersFig. 53.—Leaf and anther of Cassandra.are long and mutic (seeainfig.53), and the leaves (b) are without veins, and white and full of dots on the underside, the edges being curled inwards; and in Zenobia the corolla is bell-shaped, with the limb, which is in five lobes, curling back (seea fig.54). The stamens have the filaments (b) curiously dilated at the base; and the point of each cell of the anther is cut into two erect awns (c). The manner in which the stamens are arranged inside the corolla isshown at (d). The cells of the capsule, when ripe, open down the centre, and the seeds which are angular, are attached to a five-lobed placenta.

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