Temperature.--As the amount of heat required by the different species of Cactus varies very considerably, and as the difference between the summer and winter temperatures for them is often as great as it is important, it will be as well if we mention the temperature required by each when describing the species. It is true that the majority of Cactuses may be kept alive in one house where all would be subjected to the same temperature, but many of the plants would merely exist, and could not possibly flower. It would be easy to point to several instances of this unsatisfactory state of things. At Kew, for example, owing to the arrangements necessary for the public, it is found convenient to have the majority of the large collection of Cactuses in one house, where the plants present an imposing appearance, but where, as might be expected, a good number of the species very rarely produce flowers. The Cactuses which inhabit the plains of the Southern United States are subjected to a very high summer temperature, and a winter of intense cold; whilst on the other hand the species found in Central and South America do not undergo nearly so wide an extreme, the difference between the summer and winter temperatures of these countries being generally much less marked. A word will be said under each species as to whether it is tropical, temperate, or hardy, a tropical temperature for Cacti being in summer 70 degs., rising to 90 degs. with sun heat, night temperature 60 degs. to 70 degs., in winter 60 degs. to 65 degs. Temperate: in summer 60 degs., rising to 75 degs. with sun heat, night 60 degs. to 65 degs., in winter 50 degs. to 55 degs. The hardy species will, of course, bear the ordinary temperatures of this country; but, to enable them to withstand a very cold winter, they must be kept as dry as possible. In the colder parts of England it is not advisable to leave any of these plants outside during winter.

Insect Pests.--Notwithstanding the thickness of skin characteristic of almost every one of the Cactuses, they are frequently attacked by various kinds of garden pests when under cultivation, and more especially by mealy bug. There is, of course, no difficulty in removing such insects from the species with few or no spines upon their stems; but when the plants are thickly covered with cl.u.s.ters of spines and hairs, the insects are not easily got rid of. For Cactuses, as well as for other plants subject to this most troublesome insect, various kinds of insecticide have been recommended; but the best, cheapest, and most effectual with which we are acquainted is paraffin, its only drawback being the injury it does to the plants when applied carelessly, or when not sufficiently diluted. A winegla.s.sful of the oil, added to a gallon of soft water, and about 2oz. of soft soap, the whole to be kept thoroughly mixed by frequently stirring it, forms a solution strong enough to destroy mealy bug. In applying this mixture, a syringe should be used, or, if the plants are to be dipped overhead, care must be taken to have the oil thoroughly diffused through the water, or the plant, when lifted out, will be covered with pure paraffin, which does not mix properly with water, but swims upon the surface if allowed to stand for a few moments. The plants should be laid on their sides to be syringed with the mixture, and after they have been thoroughly wetted, they may be allowed to stand for a few minutes before being syringed with pure water. Plants that are badly infested with mealy bug should be syringed with the paraffin mixture once a day, for about a week. It is easy to do serious harm to these plants by using a stronger solution than is here recommended, and also by not properly mixing the oil with the soap and water; and the amateur cannot, therefore, be too careful in his use of this excellent insecticide. It would be easy to recommend other insecticides, so called, for Cactuses; but whilst they are less dangerous to the plants, they are often as harmless as pure water to the insects.

For scale, which sometimes infests these plants, and which is sometimes found upon them when wild, the paraffin may be used with good effect.

Thrips attack Phyllocactus, Rhipsalis, and Epiphyllum, especially when the plants are grown in less shade, or in a higher temperature, than is good for them. Fumigation with tobacco, dipping in a strong solution of tobacco, or sponging with a mixture of soap and water, are either of them effectual when applied to plants infested with thrips. The same may be said of green-fly, which sometimes attacks the Epiphyllums.

A blight, something similar to mealy bug, now and again appears on the roots of some of the varieties of Echinocactus and Cereus. This may be destroyed by dipping the whole of the roots in the mixture recommended for the stems when infested by mealy bug, and afterwards allowing them to stand for a few minutes immersed in pure water. They may then be placed where they will dry quickly, and finally, in a day or two, repotted into new compost, first removing every particle of the old soil from the roots.

Diseases.--When wild and favourably situated as regards heat and moisture, the larger kinds of Cactus are said to live to a great age, some of the tree kinds, according to Humboldt, bearing about them signs of having existed several hundred years. The same remarkable longevity, most likely, is found in the smaller kinds when wild. Under artificial cultivation there are, however, many conditions more or less unfavourable to the health of plants, and, in the case of Cactuses, very large specimens, when imported from their native haunts to be placed in our gla.s.s houses, soon perish. At Kew, there have been, at various times, very fine specimens of some of the largest-growing ones, but they have never lived longer than a year or so, always gradually shrinking in size till, finally, owing to the absence of proper nourishment, and to other untoward conditions, they have broken down and rotted. This rotting of the tissue, or flesh, of these plants is the great enemy to their cultivation in England. When it appears, it should be carefully cut out with a sharp knife, and exposed to the influence of a perfectly dry atmosphere for a few days till the wound has dried, when the plant should be potted in a sandy compost and treated as for cuttings.

Sometimes the decay begins in the side of the stem of the plant, in which case it should be cut away, and the wound exposed to a dry air.

The cause of this decay at the base or in the side of the stems of Cactuses is no doubt debility, which is the result of the absence of some necessary condition when the plants are cultivated in houses or windows in this country.

Grafted plants, especially Epiphyllums, when worked on to Pereskia stocks, are apt to grow weak and flabby through the stem wearing out, or through the presence of mealy bug or insects in the crevices of the part where the stock and scion join, in which case it is best to prepare fresh stocks of Pereskia, and graft on to them the best of the pieces of Epiphyllum from the old, debilitated plant. It is no use trying to get such plants to recover, as, when once this disease or weakness begins, it cannot easily be stopped.

CHAPTER IV.

PROPAGATION.

Cactuses may be multiplied from cuttings of the stems, from seeds, and also by means of grafting; this last method being adopted for those species which, under cultivation, are not easily kept in health when growing upon their own roots, or, as in the case of Epiphyllums, when it offers a means of speedily forming large and shapely specimens. From seeds the plants are generally freer in growth than when cuttings are used, although the seedlings are longer in growing into flowering specimens than large cuttings would be. To the amateur, the process of germination and development from the seedling to the mature stage, is full of interest and attraction, the changes from one form to another as the plant develops being very marked in most of the genera.

Seeds.--Good fresh seeds of Cactaceous plants germinate in from two to four weeks after sowing, if placed in a warm house or on a hotbed with a temperature of 80 degs. If sown in a lower temperature, the time they take to vegetate is longer; but, unless in a very low degree of heat, the seeds, if good, and if properly managed as regards soil and water, rarely fail to germinate. For all the kinds, pots or pans containing drainage to within 2 in. of the top, and then filled up with finely sifted loam and sand, three parts of the former to one of the latter, and pressed down moderately firm, will be found to answer. If the soil be moist at the time of sowing the seeds, it will not be necessary to water it for a day or two. The seeds should be scattered thinly over the surface of the soil, and then covered with about 1/8 in. of soil. Over this, a pane of gla.s.s may be placed, and should remain till the seedlings appear above the soil. Should the position where the seeds are to be raised be in a room window, this pane of gla.s.s will be found very useful in preventing the dry air of the room from absorbing all the moisture from the soil about the seeds. For the germination of Cactus, and indeed of all seeds, a certain amount of moisture must be constantly present in the soil; and after a seed has commenced to grow, to allow it to get dry is to run the risk of killing it.

[Ill.u.s.tration: FIG. 4.--SEEDLINGS OF CEREUS. a, One month after germination. b, Two months after germination. C, Three months after germination. (Magnified six times,).]

The seeds of Cactuses may be sown at anytime in the year; but it is best to sow in spring, as, after germinating, the young plants have the summer before them in which to attain sufficient strength to enable them to pa.s.s through the winter without suffering; whereas plants raised from autumn-sown seeds have often a poor chance of surviving through the winter, unless treated with great care. The seeds of all Cactuses are small, and therefore the seedlings are at first tiny globular ma.s.ses of watery flesh, very different from what we find in the seedlings of ordinary garden plants. The form of the seedling of a species of Cereus is shown at Fig. 4, and its transition from a small globule-like ma.s.s of flesh to the spine-clothed stem, which characterises this genus, is also represented. At a we see the young plant after it has emerged from the seed, the outer sh.e.l.l of which was attached to one of the sides of the aperture at the top till about a week before the drawing was made. At b, the further swelling and opening out, as it were, of what, in botanical language, is known as the cotyledon stage of development, will be seen; a month afterwards, this will have a.s.sumed the shape of a very small Cereus. It is interesting to note how the soft fleshy ma.s.s which first grows out of the seed is nothing more than a little bag of food with a tiny growing point fixed in its top, and that, as the growing point increases, the food bag decreases, till finally the whole of the latter becomes absorbed into the young stem, which is now capable of obtaining nourishment by means of its newly-formed roots.

[Ill.u.s.tration: FIG. 5.--SEEDLINGS OF OPUNTIA, SHOWING MODE OF GERMINATION. (Magnified three times).]

In the genus Opuntia, the cotyledon stage (see Fig. 5) of the plant is different from that of the Cereus, and is more like that of a cuc.u.mber.

Still, though the form is different, the purpose of the two cotyledons and the juicy stem in the seedling Opuntia is the same as in the Cereus; and, as the growing point develops, the cotyledons shrivel up and fall off, the plant food they contained having pa.s.sed into that part of the young seedling which was to be permanent. The seedlings of these two genera serve as an ill.u.s.tration of the process of germination from seed of all the Cactuses; and it must be evident that there is much that is singular and full of interest in raising these plants from seeds. As soon as the seedlings are large enough to be handled, they may be planted separately in small pots, using a compost similar to, but slightly coa.r.s.er than, that in which the seeds were sown. The soil should be kept moist till the summer is over; and after that, till the return of warm sunny weather, it will be found safest to keep the seedlings on the dry side, a little water only to be given at intervals of a week, and only when the sun is shining upon the plants.

To obtain seeds from cultivated plants, it is necessary, in order to insure fertilisation that the top of the stigma (see Fig. 2) should be dusted over with the dust-like pollen from the anthers. This may be done by means of a small camel-hair brush, which should be moistened in the mouth and then pushed among the anthers till covered with pollen, which may then be gently rubbed on to the stigma. A warm, sunny morning is the most suitable time for this operation, as fertilisation takes place much more readily under the influence of bright sunshine than at any other time. Some of the kinds have their floral organs so arranged as to be capable of self-fertilisation; still, it is always as well to give them some a.s.sistance. The night-flowering species must, of course, be fertilised either at night or very early in the morning. By using the pollen from one kind for dusting on to the stigma of another, hybrids may be obtained, and it is owing to the readiness with which the plants of this family cross with each other, that so many hybrids and forms of the genera Epiphyllum and Phyllocactus have been raised. It would be useless to attempt such a cross as Epiphyllum with Cereus giganteus, because of their widely different natures; but such crosses as Epiphyllum with Phyllocactus, and Cereus flagelliformis with C.

speciosissimus, have been brought about. To an enthusiast, the whole order offers a very good field for operations with a view to the production of new sorts, as the different kinds cross freely with each other, and the beautiful colours of the flowers would most likely combine so as to present some new and distinct varieties.

Cuttings.--No plants are more readily increased from stem-cuttings than Cactuses; for, be the cutting 20 ft. high, or only as large as a thimble, it strikes root readily if placed in a warm temperature and kept slightly moist. We have already seen how, even in the dry atmosphere of a museum, a stem of Cereus, instead of perishing, emitted roots and remained healthy for a considerable time, and it would be easy to add to this numerous other instances of the remarkable tenacity of life possessed by these plants. At Kew, it is the common practice, when the large-growing specimens get too tall for the house in which they are grown, to cut off the top of the stem to a length of 6 ft. or 8 ft., and plant it in a pot of soil to form a new plant. The old base is kept for stock, as it often happens that just below the point where the stem was severed, lateral buds are developed, and these, when grown into branches, are removed and used as cuttings. Large Opuntias are treated in the same way, with the almost invariable result that even the largest branches root freely, and are in no way injured by what appears to be exceedingly rough treatment. Large cuttings striking root so freely, it must follow that small cuttings will likewise soon form roots, and, so far as our experience--which consists of some years with a very large collection of Cactuses--goes, there is not one species in cultivation which may not be easily multiplied by means of cuttings. The nature of a Cactus stem is so very different from the stems of most other plants, that no comparison can be made between them in respect of their root-developing power; the rooting of a Cactus cutting being as certain as the rooting of a bulb. The very soft, fleshy stems of some of the kinds such as the Echinocactus, should be exposed to the air for a time, so that the cut at the base may dry before it is buried in the soil. If the base of a plant decays, all that is necessary is the removal of the decayed portion, exposure of the wound to the air for two or three days, and then the planting of the cutting in a dry, sandy soil, and placing it in a warm moist house till rooted. All cuttings of Cactuses may be treated in this way. If anything proves destructive to these cuttings, it is excessive moisture in the soil, which must always be carefully guarded against.

Grafting.--The object of grafting is generally either to effect certain changes in the nature of the scion, by uniting it with a stock of a character different from its own, which usually results in the better production of flowers, fruit, &c., or to multiply those plants which are not readily increased by the more ordinary methods of cuttings or seeds.

In the case of Cactuses, however, we resort to grafting, not because of any difficulty in obtaining the kinds thus treated from either cuttings or seeds, as we have already seen that all the species of Cactuses grow freely from seed, or are easily raised from cuttings of their stems, nor yet to effect any change in the characters of the plants thus treated, but because some of the more delicate kinds, and especially the smaller ones, are apt to rot at the base during the damp, foggy weather of our winters; and, to prevent this, it is found a good and safe plan to graft them on to stocks formed of more robust kinds, or even on to plants of other genera, such as Cereus or Echinocactus. By this means, the delicate plants are raised above the soil whence the injury in winter usually arises, and they are also kept well supplied with food by the more robust and active nature of the roots of the plant upon which they are grafted. Grafting is also adopted for some of the Cactuses to add to the grotesqueness of their appearance; a spherical Echinocactus or Mamillaria being united to the columnar stem of another kind, so as to produce the appearance of a drum stick; or a large round-growing species grafted on to three such stems, which may then be likened to a globe supported upon three columns. As the species and genera unite freely with each other, it is possible to produce, by means of grafting, some very extraordinary-looking plants, and to a lover of the incongruous and "queer," these plants will afford much interest and amus.e.m.e.nt. Besides the above, we graft Epiphyllums, and the long drooping Cereuses, such as C. flagelliformis, because of their pendent habit, and which, therefore, are seen to better advantage when growing from the tall erect stem of some stouter kind, than if allowed to grow on their own roots. By growing a Pereskia on into a large plant, and then cutting it into any shape desired, we may, by grafting upon its spurs or branches a number of pieces of Epiphyllum, obtain large flowering specimens of various shapes in a comparatively short time. For general purposes, it is usual to graft Epiphyllums on to stems, about 1 ft. high, of Pereskia aculeata; pretty little standard plants being in this way formed in about a year from the time of grafting, As an instance of how easily some kinds may be grafted, we may note what was done with a large head of the Rat's-tail Cactus which had been grown for some years on the stem of Cereus rostratus, but which last year rotted off just below the point of union. On re-grafting this head on to the Cereus a little lower down, it failed to unite, and, attributing the failure to possible ill-health in the stock, we determined to transfer the Rat's-tail Cactus to a large stem of Pereskia aculeata, the result being a quick union and rapid, healthy growth since. Upon the same stock some grafts of Epiphyllum had previously been worked, so that it is probable these two aliens will form on their nurse-stem, the Pereskia, an attractive combination. In Fig. 6 we have a fine example of this kind of grafting. It represents a stem of Pereskia Bleo upon which the Rat's-tail Cactus and an Epiphyllum have been grafted.

[Ill.u.s.tration: FIG. 6. PERESKIA BLEO, WITH EPIPHYLLUM AND CEREUS FLAGELLIFORMIS GRAFTED UPON IT.]

For most plants the operation of grafting must be carefully and skilfully performed, but in the case of Cactuses very little skill is necessary if one or two rules, which apply to all kinds of grafting, are observed. The period of vigorous growth, and while the sap of both the stock and the scion is in motion, is the most favourable time for the operation. It is then only necessary, in order to bring about a speedy union, that the parts grafted should be cut so as to fit each other properly, and then bound or in some way fastened together so that they will remain in close contact with each other till a union is effected. A close atmosphere and, if possible, a little shade should be afforded the worked plants till the grafts have taken. The ligature used should not be bound round the graft too tightly, or it will prevent the flow of the sap; if bound tightly enough to hold the parts together and to prevent their slipping, that will be found quite sufficient.

Epiphyllums are treated as follows: Cuttings of Pereskia are rooted and grown on to the required size, and in the month of September they are headed down, the tops being used as cuttings. Grafts of Epiphyllum are then prepared by cutting them to the required length, usually about 6 in., and removing a thin slice of the fleshy stem on each side so as to form a flat wedge. The stem of Pereskia is then split down about 1 in.

with a sharp knife, and into this the wedge of the graft is inserted, and fastened either by means of a small pin pa.s.sed through the stem and graft about half-way up the slit, or by binding round them a little worsted or matting, the former being preferred. The worked plants are then placed in a close handlight or propagating frame, having a temperature of about 75 degs., where they are kept moist by sprinkling them daily with water; they must be shaded from bright sunlight. As soon as a union has been effected, which will be seen by the grafts beginning to grow, the ligature and pin should be removed, and the plants gradually hardened off by admitting air to the box, till finally they may be removed to the house where it is intended to grow them. In a cottage window this operation may be successfully performed if a box with a movable gla.s.s top, or a large bell gla.s.s, be used to keep the grafts close till they have taken.

For the spherical-stemmed kinds of Mamillaria, Cereus, Echinocactus, &c., a different method is found to answer. Instead of cutting the base of the graft to a wedge shape, it is simply cut across the base horizontally, or, in other words, a portion of the bottom of the graft is sliced off, and a stock procured which, when cut across the top, will about fit the wound at the base of the scion; the two sliced parts are placed together, and secured either by pa.s.sing a piece of matting a few times over the top of the graft and under the pot containing the stock, or by placing three stakes around it in such a way that, when tied together at the top, they will hold the graft firmly in position.

Another method is that of cutting the base of the scion in the form of a round wedge, and then scooping a hole out in the centre of the stock large enough to fit this wedge; the scion is pressed into this, and then secured in the manner above mentioned. To graft one spherical-stemmed kind on to three columnar-stemmed ones, the latter must first be established in one pot and, when ready for grafting, cut at the top into rounded wedges, three holes to correspond being cut into the scion. When fixed, the top should be securely fastened by tying it to the pot, or by means of stakes. For this last operation, a little patience and care are necessary to make the stocks and scions fit properly; but if the rules that apply to grafting are properly followed, there will be little fear of the operation failing. In the accompanying ill.u.s.trations, we have a small Mamillaria stem grafted on to the apex of the tall quadrangular-stemmed, night-flowering Cereus (Fig. 7), and also a cylindrical-stemmed Opuntia worked on a branch of the flat, battledore-like Indian Fig (Fig. 8.)

[Ill.u.s.tration: FIG. 7.--GRAFT OF MAMILLARIA RECURVA ON CEREUS NYCTICALUS.]

[Ill.u.s.tration: FIG. 8.--GRAFT OF OPUNTIA DECIPIENS ON O. FICUS-INDICA.]

In the hands of a skilful cultivator, the different Cactuses may be made to unite with one another almost as easily as clay under the moulder's hands; whilst even to the amateur, Cactuses afford the easiest of subjects for observing the results of grafting.

CHAPTER V.

THE GENUS EPIPHYLLUM.

(From epi upon, and phyllon, a leaf).

It is now about a century since some of the most beautiful of Cactaceous plants came into cultivation in this country, and amongst them was the plant now known as E. truncatum, but then called Cactus Epiphyllum; the name Cactus being used in a generic sense, and not, as now, merely as a general term for the Natural Order. Introduced so early, and at once finding great favour as a curious and beautiful flowering plant, E.

truncatum has been, and is still, extensively cultivated, and numerous varieties of it have, as a consequence, originated in English gardens.

We do not use the seeds of these plants for their propagation, unless new varieties are desired, when we must begin by fertilising the flowers, and thus obtain seeds, which should be sown and grown on till the plants flower.

Epiphyllums have already "broken" from their original or wild characters, and are, therefore, likely to yield distinct varieties from the first sowing. In the forests which clothe the slopes of the Organ Mountains, in Brazil, the Epiphyllums are found in great abundance, growing upon the trunks and branches of large trees, and occasionally on the ground or upon rocks, up to an elevation of 6000 ft. It was here that Gardner, when travelling in South America, found E. truncatum growing in great luxuriance, and along with it the species known as E.

Russellianum, which he sent to the Duke of Bedford's garden, at Woburn, in 1839. These two species are the only ones now recognised by botanists, all the other cultivated kinds being either varieties of, or crosses raised from, them. The character by which Epiphyllums are distinguished from other Cactuses, is their flattened, long, slender branches, which are formed of succulent, green, leaf-like branchlets, growing out of the ends of each other, to a length of from 3 ft. to 4 ft.

As in the majority of Cactuses, the stems of Epiphyllum become woody and almost cylindrical with age, the axes of the branchlets swell out, and the edges either disappear or remain attached, like a pair of wings.

Cultivation.--Epiphyllums require the temperature of an intermediate house in winter, whilst, in summer, any position where they can be kept a little close and moist, and be shaded from bright sunshine, will suit them. Remembering that their habit, when wild, is to grow upon the trunks of trees, where they would be afforded considerable shade by the overhanging branches, we cannot be wrong in shading them from direct sunshine during summer. Some growers recommend placing these plants in a hot, dry house; but we have never seen good specimens cultivated under such conditions. All through the summer months, the plants should be syringed both morning and evening; but by the end of August they will have completed their growth, and should, therefore, be gradually exposed to sunshine and air.

It is advisable to discontinue the use of the syringe from September till the return of spring, but the plants should always be kept supplied with a little moisture at the root and in the air about them during the winter months. In this respect, these plants and the Rhipsalis are exceptions among Cactuses, as all the others are safest when kept dry during the cold, dull weather between September and April. The soil most suitable for them is a mixture of peat, loam, and sand, unless a light and fibrous loam be obtainable, which is, perhaps, the best of all soils for these plants, requiring only the addition of a little rotted manure or leaf-mould, silver sand, and some small brick rubble. The Pereskia stock is not a stout-rooted plant, and does not, therefore, require much root-room, although, by putting in plenty of broken crocks as drainage, the soil s.p.a.ce in the pots may be reduced to what is considered sufficient for the plant. If small pots are used, the head of the plant is apt to overbalance the whole. The stems should be secured to stout stakes, and, if large, umbrella-like specimens are wanted, a frame should be made in the form of an umbrella, and the stem and branches fastened to it. Smaller plants may be kept in position by means of a single upright stake, which should be long enough to stand an inch or two above the head of the plant, so that the stoutest branches may be supported by attaching a piece of matting to them, and fastening it to the top of the stake. In the remarks upon grafting we mentioned the large pyramidal specimens of Epiphyllum which are grown by some cultivators for exhibition purposes; and, although these plants are much rarer at exhibitions now than they were a few years ago, yet they do sometimes appear, especially in the northern towns, such as Liverpool and Manchester.

It would not be easy to find a more beautiful object during winter than an Epiphyllum, 5 ft. or 6 ft. high, and nearly the same in width at the base, forming a dense pyramid of drooping, strap-like branches bearing several hundreds of their bright and delicate coloured blossoms all at one time, and lasting in beauty for several weeks. With a little skill and patience, plants of this size may be grown by any amateur who possesses a warm greenhouse; and, although it is not easy to manage such large plants in a room window, handsome little specimens of the same form may be grown if the window is favourably situated and the room kept warm in winter. Mr. J. Wallis, gardener to G. Tomline, Esq., of Ipswich, has become famous for the size and health of the specimens he has produced. Writing on the cultivation of Epiphyllums, Mr. Wallis gives the following details, which are especially valuable as coming from one of the most successful cultivators of these beautiful plants:

"The Epiphyllums here are grown for flowering in the conservatory, and are usually gay from the first week in November till February. During the remainder of the year, they occupy a three-quarter span-roof house, in which an intermediate temperature is maintained. All our Epiphyllums are grafted on the Pereskia aculeata. We graft a few at intervals of two or three years, so, if any of the older plants become sickly or shabby, they are thrown away, and the younger ones grown on. Some of the stocks are worked to form pyramids, and some to form standards. The height of the pyramids is 6 ft., and, to form these, six or eight scions are inserted. The heads of the standards are on stems ranging in height from 4 ft. down to 1 ft. To form these heads, only one scion is put on the stock. Some of our oldest pyramids are 4 ft. or 5 ft. through at the base, and the heads of the standards quite as much. When in flower, the heads of the latter droop almost to the pots. The pyramids occupy No.2 and No.4 sized pots, the standards 8's and 12's. Each plant is secured to a strong iron stake, with three p.r.o.ngs fitting the inside of the pot, and the Epiphyllum is kept well supported to the stake by ties of stout wire. After the plants are well established, they are easily managed, and go many years without repotting; but, of course, we top-dress them annually, previously removing as much of the old soil as will come away easily. We grow these plants with plenty of ventilation on all favourable occasions, and they are seldom shaded. During active growth, water is given freely, occasionally liquid manure; they are also syringed daily. After the season's growth is completed, water is given more sparingly, and syringing is dispensed with."

When grown on their own roots, Epiphyllums are useful for planting in wire baskets intended to hang near the gla.s.s; large and very handsome specimens form in a few years, if young rooted plants are placed rather thickly round the sides of the baskets, and grown in a warm house.

Epiphyllums are employed with good effect for covering walls, which are first covered with peaty soil by means of wire netting, and then cuttings of the Epiphyllums are stuck in at intervals of about 1 ft. The effect of a wall of the drooping branches of these plants is attractive even when without their beautiful flowers; but when seen in winter, clothed with hundreds of sparkling blossoms, they present a most beautiful picture. Large plants of Pereskia may be trained over pillars in conservatories and afterwards grafted with Epiphyllums; in fact, there are many ways in which these plants may be effectively employed in gardens.

SPECIES.

E. truncatum (jagged); Bot. Mag. 2562.--Branchlets from 1 in. to 3 in.

long, and 1 in. wide, with two or three distinct teeth along the edges, and a toothed or jagged apex (hence the specific name). The flowers are 3 in. long, curved above and below, not unlike the letter S; the petals and sepals reflexed, and exposing the numerous yellow anthers, through which the club-headed stigma protrudes; colour, a deep rose-red, the base of the petals slightly paler. The varieties differ in having colours which vary from almost pure white, with purplish tips, to a uniform rich purple, whilst such colours as salmon, rose, orange, and scarlet, are conspicuous among them.

[Ill.u.s.tration: FIG. 9.--EPIPHYLLUM RUSSELLIANUM.]

E. Russellianum (Russell's); Fig. 9.--This has smaller branchlets than the type plant (E. truncatum), and is thus easily distinguished; they do not exceed 1 in. in length and in. in width, whilst the edges are irregularly and faintly notched, not distinctly toothed, as in E.

truncatum. The flowers are a little larger than in the older kind, and are not curved, whilst the petals are narrower; their colour is bright rosy-red. This species flowers rather later in the year than E.