M. Scheerii (Scheer's).—Stem 7 in. high, and 5 in. in diameter at the base; tubercles large, swollen, somewhat flattened, pale green, watery, woolly in the axils, the tops crowned with about a dozen brown spines, 1 in. long, one central, the others radial. Flowers terminal, erect, with several whorls of spreading, recurved petals, the lower ones tinged with crimson, the upper pale yellow, and forming a shallow cup, 2 in. across; anthers forming a compact sheaf in the centre. Flowers in summer. This distinct and very pretty species was introduced many years ago from Mexico, where it was discovered in 1845 by a Mr. Potts, to whose love for these plants we are indebted for a great many choice kinds collected and sent to England by him. It grows naturally in a red, sandy loam, and under cultivation requires warm-house treatment, except during the autumn, when it may be placed in a frame and exposed to full sunshine and plenty of air.

M. Schelhasii (Schelhas').—A pretty little tufted kind, its habit and size being shown in Fig. 69. The stem produces offsets freely at the base, which grow into full-sized stems, and develop young ones, till a compact cushion is formed. Tubercles closely arranged, cylindrical, shining green, with fifteen to twenty radial, white, hair-like spines, 1/2 in. long, and three inner ones, which are thicker, purplish in colour, usually only one being hooked. Flowers white, with a line of rose down the middle of each petal, 3/4 in. across. Flowering season, beginning of summer. Native of Mexico. It may be grown out of doors in a sunny position in summer, and wintered on a shelf in a greenhouse.



M. Schiedeana (Schiede's).—Stem globose, 3 in. to 5 in. high, thickly clothed with long, narrow, pointed tubercles, the bases of which are set in white wool, whilst the apices are crowned with tiny stars of white silky spines; more like the pappus of a Composite than the spines usually found on Cactuses. A healthy plant has a very pretty and silky appearance which cannot well be described. The flowers are small and unattractive; they are succeeded by the red fruits, which remain on the plant a long time, and add to its beauty. Native country, Mexico. Introduced 1838. Should be grown in a greenhouse where frost is excluded, and where there is plenty of sunlight at all times. It is easily increased, either from seeds or by means of the offsets developed at the base of old stems.

M. semperviva (ever-living); Fig. 70.—Stem pear-shaped, 3 in. wide, the top slightly depressed. Tubercles conical, 1/4 in. long, their bases set in a cushion of white wool, their tips bearing tiny tufts of wool, and four small spines, which fall away on the tubercles becoming ripe, leaving two short, diverging, central spines. Flowers small, not ornamental, and scantily developed near the outside of the top. Native of Mexico; in meadows and thickets near Zimapan, at 5000 ft. elevation. It thrives with us when grown in a frame in summer, and wintered in a cool greenhouse or frame.



M. senilis (hoary).—Stem about 3 in. high, spherical, unbranched, except when very old, when it becomes proliferous at the base; tubercles crowded, small, arranged spirally, and crowned with clusters of long, radiating spines, which are almost white, hair-like, and become thickly interwoven, as in the Old Man Cactus (Pilocereus senilis). The central spine is black, and hooked at the tip. Flowers on the top of the stem, near the centre; the petals toothed, spreading, and forming a deep cup, with a cluster of tall stamens standing erect in the middle; colour bright scarlet. The flowers, which appear in summer, remain open about eight hours. Native country unknown; cultivated in France in 1845. This plant is difficult to preserve in health, the best method being that of grafting it on to a short Cereus, or a robust kind of Mamillaria, such as M. cirrhifera. It is a pretty plant at all times, even when dead, for we have seen plants of it preserve the appearance of live specimens long after they have rotted and dried up in the centre, nothing remaining but the shell formed by the skin and silvery spines. There is a close resemblance between this species and M. Grahami.

M. stella-aurata (golden star).—This little plant obtains its name from the rich golden-yellow of its stellate clusters of spines, which are arranged thickly on the tips of the small, pointed tubercles. It belongs to the group called Thimble Cactuses, of which it is one of the prettiest. The stems are tufted, branching freely at the base, and rising to a height of about 2 in. Flowers small, whitish, and much less ornamental than the berry-like fruits which succeed them, and which are egg-shaped, 1/2 in. long, and a deep rose-colour. M. tenuis is a variety of this, with almost white spines. Native of Mexico. Introduced 1835. May be cultivated under a bell-glass in a room window, the only danger being damp during winter, which must be carefully avoided.

M. sub-polyhedra (usually many-sided); Fig. 71.—Stem simple till it becomes old, when it develops offsets at the base, broadly cylindrical, 8 in. high, 5 in. in diameter. Tubercles four-sided at base, prism-shaped, bearing pads of white wool in the corners at the base, and crowned with tufts of from four to seven spines, usually all radial, sometimes one central. The flowers, which usually appear in May, are arranged in a zone on the top of the old stems; sepals greenish-yellow, petals bright red. Fruit 1 in. long, pear-shaped, scarlet. Native of South Mexico, at high elevations. It may be grown outside in summer, and wintered in a heated greenhouse or frame. This is a singular-looking plant, the tubercles having an appearance suggestive of carving. It is a slow grower, and requires careful attention in winter, when sometimes the roots all perish and the base of the stem rots.



M. sulcolanata (woolly-grooved); Fig. 72.—Stem simple when young, proliferous at the sides when old, the young plants developing from the apices of the tubercles, and not in the axils, as is usual. The tubercles are nut-shaped, large, the bases surrounded by white wool, the points bearing eight to ten rigid, brown spines, all radiating from a little pad of wool. Flowers large, nearly 2 in. across, bright yellow, poppy-scented, the spread of the petals suggesting Paris Daisies; they are freely developed on the apex of the stem in June, and on till August. Fruit egg-shaped, glaucous-green. Native country, South Mexico; introduced 1836. This charming little plant should be grown in a frame exposed to full sunshine all summer, and removed to a shelf in a warm greenhouse in winter. With such treatment it grows and flowers freely. Grafted on to a Cereus or Opuntia it is healthier than when on its own roots.



M. tetracantha (four-spined); Bot. Mag. 4060.—Stem the size and shape of an ostrich's egg, thickly studded with small, conical tubercles, woolly at the base, the apices bearing each four spreading spines, 3/4 in. long, rather stout, straight, brown when young, becoming almost white with age. Flowers numerous, small, arranged as in M. sanguinea, to which and M. cirrhifera this species is closely related. They are bright rose in colour, with orange-yellow anthers, and are developed in July. Native of Mexico. Requires the same treatment as M. cirrhifera.

M. tuberculosa (tubercled).—This is a very pretty and distinct plant, of recent introduction, and easily cultivated. It has a central stem, 6 in. high by 2 in. in diameter, conical in shape, and surrounded at the base by globose branches or offsets. The tubercles are closely set in numerous spiral rows, and are 1/2 in. long, rather narrow, pointed, with a crown of radial spines, very slender, hair-like, white, and 1/2 in. long; central spines three or four, 1/2 in. long. At the base of each tubercle is a pea-like tuft of white wool. In this kind the spines fall from the old tubercles, which are persistent, gradually hardening to a cork-like substance. The flowers are produced in the apex of the stem, and are 1 in. long and wide, daisy-like, pale purple in colour; they are succeeded by red, oval berries, which are as pretty as the flowers. About five flowers are developed on each stem annually—May and June. Native of Mexico, in the mountains. It thrives when grown in an ordinary greenhouse, on a shelf, in full sunshine.

M. turbinata (top-shaped); Bot. Mag. 3984.—Stem globose, depressed at top, about 3 in. in diameter, pale glaucous-green; tubercles quadrangular, flattened at the apex, and bearing, when young, from three to five erect, slender, hair-like spines, which fall off soon after the tubercles ripen, exposing little depressions or umbilica, and giving the stem a bald, pudding-like appearance, quite distinct from any other kind. Flowers from the centre of the stem, short, about 1 in. across, pale yellow, with a reddish tint outside; anthers yellow. Two or three flowers are usually expanded together in the month of June. Native country, Mexico.

M. uncinata (hooked).—Stem globose, simple, about 4 in. in diameter; tubercles closely pressed against each other at the base, where they are four-angled; in length they are 1/4 in., and they are blue-green in colour. Apex bearing four short spines, arranged crosswise, and 1/4 in. long; central spine slightly longer, yellow, and hooked. The flowers are 1 in. long and wide, erect, the tube hidden by the young mammae, amongst which they appear in May and June; they are purple in colour, a line of deeper tint running down the middle of each petal. Like all the kinds with short, angular tubercles, this species is easily managed, flowers freely and profusely, and always ripens seeds. Native of Mexico. It may be grown in a frame, or even out of doors, all through the summer, removing it to a greenhouse for the winter.

M. vetula (old).—One of the small Thimble Cactuses, its stems seldom exceeding 3 in. in height by 11/2 in. in diameter. Tubercles 1/4 in. long, conical, with a radial crown of fine, hair-like yellow spines, 1/4 in. long, and a solitary central spine, 1/2 in. in length, and coloured red. Flowers terminal, just peeping above the tubercles; sepals and petals acute, yellow, 3/4 in. long; anthers yellow; stigma white. An old garden plant, introduced from Mexico. It flowers in May and June. For its cultivation it may be treated as recommended for M. pusilla.

M. villifera (hair-bearing).—Stem similar to the last, but usually proliferous at the base; tubercles angular, short, woolly in the axils, and bearing four rigid, short, reddish-brown spines on the apex. Flowers pale rose, with a line of purple down the middle of each petal; they are developed near the top of the stem, in May. Native country, Mexico. This plant thrives if treated as recommended for M. pusilla. There are several varieties known, distinguished by their paler or darker flowers, or by a difference in the length and arrangement of the spines.

M. viridis (green).—Stem 4 in. high by 3 in. in diameter, proliferous at the base; tubercles short, four-angled, crowded in spiral rows, woolly at the base, bearing each five or six radiating hair-like spines on the apex, and one central erect one, none more than 1/4 in. long. Flowers erect, on top of stem, with recurved, pale yellow petals, 1 in., long; they are produced in May and June. Introduced from Mexico in 1850. It may be grown in a sunny frame out of doors during summer, and on a dry, warm greenhouse shelf in winter.

M. vivipara (stem—sprouting).—A tufted, free-growing Thimble Cactus, producing its small stems in such profusion as to form a cluster as much as 3 ft. in diameter. The small tubercles are hidden by the numerous radial spines, which are in clusters of about twenty; they are white, hair-like, stiff and 1/2 in. long; the central spines, numbering from four to six, are a little longer. Flowers from apex of stem, 11/2 in. long and wide, and composed of about thirty fimbriated sepals and twenty-five to forty narrow petals; colour bright purple. Fruit 1/2 in. long, pale green when ripe. The flowers, which appear in May and June, usually expand after mid-day. Native of Louisiana. In the North-West plains and Rocky Mountains of North America this plant is abundant, often forming wide cushion-like tufts, which, when covered with numerous purple, star-like flowers, have a pretty effect. In Utah and New York it is commonly cultivated as a hardy garden plant, bearing exposure to keen frosts and snow without suffering; but it would not thrive out of doors in winter with us, unless covered by a handlight during severe weather, and protected from heavy rains in winter. It likes a strong, clayey soil.

M. v. radiosa (Fig. 73).—This variety is distinguished by its larger flowers and shorter spines.



M. Wildiana (Wild's).—An old garden Cactus, and one of the prettiest of the tufted, small-stemmed kinds. Its largest stems are 3 in. high by about 11/2 in. in diameter, and bear spiral rows of clavate, dark green, crystallised tubercles, 1/2 in. long, with about ten radial white spines, 1/2 in. long, the three upper spines, together with the solitary central hooked one, being yellow. Flowers small, numerous on the apices of the stems, rose-coloured, lined with purple; they are developed in summer. This also forms dense tufts of stems. A specimen at Kew, only a few years old, has already over thirty heads. It is a native of Mexico, at an altitude of 5000 ft., growing on lava and basalt, and even on the trunks of trees. For its cultivation, a shelf in a sunny greenhouse is a most suitable position, both in winter and summer. Introduced 1835.

M. Wrightii (Wright's).—This is a charming little plant, of something the same character as M. dolichocentra. It has not long been cultivated in gardens, but being easy to manage, and exceptionally pretty, it is sure to become a favourite as it gets known. Stem rounded above, narrowed and peg-top-like at the base, the top flattened, about 3 in. across, height about the same. Tubercles conical, 1/2 in. long, shining green, and bearing a tuft of six or eight spines, which are straight, hair-like, white, and 1/2 in. long; there are two central spines, of same length, and hooked. Flowers in the top of the stem, 1 in. long and wide, bright purple; they are succeeded by egg-shaped, purple berries, 1 in. long, and prettily arranged among the tubercles. In England a warm house seems most suitable for this species. It likes plenty of moisture and sunlight during the summer, whilst making new growth; but in winter, when at rest, it ought to be kept on a shelf, and just moistened overhead in bright weather. There are healthy examples of it at Kew. Flowering season, May and June. Native country, Mexico. Introduced about 1878.

M. Zucchariniana (Zuccharini's).—Stem simple, globose, often attaining a height of 10 in. by about 7 in. in diameter. Tubercles dark green, conical, 1/3 in. long, 1/2 in. broad at base, naked at the point, but with four to six spines springing from the areole a little below the point; spines ash-coloured, stiff, black-tipped. Flowers in a ring about the top of the stem, length 1 in., the tube enveloped in long, black, twisted hairs; sepals brown-purple; petals narrow, sharp-pointed, purple-rose coloured; stamens white and yellow; stigma rose-coloured. Flowers in June and July. Native of Mexico. A large, handsome-stemmed kind, easily kept in health, and flowering freely if grown on a shelf in a cool greenhouse in winter, and placed in a warm, sunny position out of doors in summer. It produces seeds freely, and pretty plants, 3 in. or more in diameter, may be obtained in two years from seeds. By grafting it, when young, on the stem of a Cereus or cylindrical Opuntia, a healthy, drumstick-like plant is easily obtained.



CHAPTER XII.

THE GENUS LEUCHTENBERGIA.

(Named in honour of Prince Leuchtenberg.)

Among the many instances of plant mimicry that occur in the Cactus order, the most remarkable is the plant here figured. Remove the flower from Leuchtenbergia, and very few people indeed would think of calling it a Cactus, but would probably consider it a short-leaved Yucca. In habit, in form, in leaf, and in texture, it more resembles a Yucca or an Agave than anything else, and when first introduced it was considered such by the Kew authorities until it flowered. The leaves, or rather tubercles, are sometimes longer and slenderer than in Fig. 74. The nearest approach to this plant is Mamillaria longimamma, in which the tubercles are 1 in. or more long, finger-shaped, and crowned with a few hair-like spines. But the Leuchtenbergia bears its flowers on the ends of the tubercles, and not from the axils, as in all others. This peculiarity leads one to infer that tubercles are modified branches, the spines representing the leaves. Some species of Mamillaria and Echinocactus develop young plants from the tops of their tubercles; and this also points to the probability that the latter are branches. In Leuchtenbergia, the tubercles fall away as the plant increases in height, leaving a bare, woody stem similar to that of a Yucca.

Cultivation.—The Leuchtenbergia has always been difficult to keep in health. It thrives best when kept in a warm, sunny house during winter, and in an exposed, airy, warm position under a frame during summer. It may be watered regularly whilst growing—that is, from April to September—and kept quite dry all winter. The soil should be well-drained loam, and the roots should have plenty of room. A specimen may be seen in the Kew collection.

Propagation.—This may be effected from seeds, or by removing the head from an old plant, putting the former in sand, and placing it under a bell-glass to root, watering it only about once a week till roots are formed. The old stem should be kept dry for about two months, and then watered and placed in a sunny, moist position, where it can be syringed once a day. A shelf in a stove is the best position for it. Here it will form young buds in the axils of the withered tubercles, and on the edges of the persistent parts of the tubercles themselves. They first appear in the form of tiny tufts of yellowish down, and gradually develop till the first leaf-like tubercle appears. When large enough, the buds may be removed and planted in small pots to root. If an old plant is dealt with in this way in April, a batch of young ones should be developed and rooted by October. Grafting does not appear to have ever been tried for this plant. When sick, the plant should be carefully washed, and all decayed parts cut away; it may then be planted in very sandy loam, and kept under a bell-glass till rooted.



SPECIES.

L. principis (noble); Fig. 74.—This, the only species known, was introduced from Mexico to Kew in 1847, and flowered the following year. The plant attains a height of 1 ft. or more, the stem being erect, stout, clothed with the persistent, scale-like bases of the old, fallen-away tubercles, the bases having dried up and tightened round the stem. The upper part is clothed with the curved, leaf-like tubercles, from 3 in. to 6 in. long, grey-green in colour, succulent, with a tough skin, triangular, and gradually narrowed to a blunt point, upon which are half a dozen or more thin, flexuous, horny filaments, neither spines nor hairs in appearance, but almost hay-like; the central one is about 5 in. long, and the others about half that length. The flowers are borne on the ends of the young, partly-developed tubercles, near the centre of the head; they are erect, tubular, 3 in. to 4 in. long, scaly, gradually widening upwards; the sepals and petals are numerous, and form a beautiful flower of the ordinary Cactus type, quite 4 in. across, and of a rich, clear yellow colour. The anthers, which also are yellow, form a column in the centre, through which the nine-rayed stigma protrudes. Strong plants sometimes produce two flowers together.



CHAPTER XIII.

THE GENUS PELECYPHORA.

(From pelekyphoros, hatchet-bearing; referring to the shape of the tubercles.)

IKE Leuchtenbergia, this genus is monotypic, and it is also rare, difficult to cultivate, and exceptionally interesting in structure. It is closely related to the Mamillarias, as may be seen, by comparing the Figure here given with some of them; indeed, it was once known as M. asellifera, having been described under that name when first introduced, in 1843. From Mamillaria, however, it differs in the form of its tubercles, which are hatchet-shaped, and cleft at the apex, where each division is clothed with small, horny, overlapping scales, not unlike the back of a woodlouse—hence the specific name.

Cultivation.—The Hatchet Cactus grows very slowly, specimens such as that represented in our Illustration being many years old. We have seen healthy plants, freshly imported, grow for a few months, and then suddenly die, the inside of the stem rotting whilst outside it looked perfectly healthy. It is always grown on its own roots, but probably it would thrive better if grafted on the stem of some dwarf Cereus or Echinocactus.



Propagation.—The propagation of Pelecyphora is easiest effected by means of seeds, which, however, are not always procurable. It is stated by Labouret, a French writer on Cactuses, that the first plants introduced arrived dead, but a few seeds were found in a withered fruit on one of the dead stems, and from these the first plants grown in Europe were raised. M. de Smet of Ghent, had a large stock of this Cactus a few years ago, and a German nurseryman, H. Hildmann, of Oranienberg, near Berlin, usually has many young plants of it for sale.

SPECIES.

P. aselliformis (woodlouse-like); Fig. 75.—The size, habit, and structure of this plant are so well represented in the Figure that little description is necessary. The stems are simple till they get about 3 in. high, when they develop offsets about the base, which may either be removed to form new plants, or allowed to remain and grow into a specimen like that in the Illustration. The flowers are large for the size of the plant, and they are developed freely in the apex of the stems in the early part of the summer. The tube is very short, naked, and completely hidden by the young mammae; sepals and petals in four series, the outer one pale purple, the inner of a deep purple colour; stamens very numerous, and the stigma has only four erect lobes. The plant was first described from examples cultivated in Berlin in 1843, but the flowers were not known till 1858. There are several varieties known, viz., P. a. concolor, which is distinguished by the whole of the flower being deep purple in colour; P. a. pectinata has larger scales (spine-tufts); and P. a. cristata is, as its name denotes a kind of cockscomb or crested form. They are all natives of Mexico.



CHAPTER XIV.

THE GENUS OPUNTIA.

(The old Latin name used by Pliny, and said to have been derived from the city of Opus.)

There are about 150 species of Opuntia known, all of them natives of the American continent and the West Indies, though a considerable number have become naturalised in many other parts of the world. They are, with very few exceptions, easily distinguished from all other Cactuses by the peculiar character of their stems and spines; they are also well marked in the structure of their flowers. They vary in size from small, trailing, many-branched plants, never exceeding 6 in. in height, to large shrubs 8 ft. to 30 ft. high. (Humboldt states that he saw "Opuntias and other Cactuses 30 ft. to 40 ft. high.") Generally the branches are nearly flat when young, and shaped like a racquet or battledore; but in some species the branches are round (i.e., in O. cylindrica, O. subulata, O. arborescens, &c.). All the kinds have fleshy stems, which ultimately become cylindrical and woody. At first they consist of fleshy joints, superposed upon one another, the joints varying considerably in size and shape. When young they bear small fleshy leaves along with the spine-tufts; but the former fall off at an early stage, whilst the spines are altered in length or number as the joints get old. In one or two kinds the spines fall away when the joints begin to harden, and in O. subulata the leaves are large and persistent.

The nature of the spines of Opuntias is of a kind that is not likely to be forgotten by anyone coming into contact with them. Every spine, from the tiny bristles, hardly perceptible to the naked eye, to the stout, needle-like spears which are found on the branches of some kinds, is barbed, and they are so very sharp and penetrating that even a gentle touch is sufficient to make them pierce the skin. Once in they are very difficult to get out; the very fine ones can only be shaved level with the skin, and left to grow out, whilst the larger must be cut out if they have penetrated to any depth. This horrid character in Opuntias, whilst rendering them disagreeable to the gardener, has been turned to good account in many of our colonies, where they are commonly used as fences. A good hedge of such kinds as O. Tuna or O. horrida is absolutely impassable to both man and beast, and as the stems are too watery to be easily destroyed by fire, their usefulness in this way could not be surpassed. As all the Opuntias will grow in the very poorest of soils, and even on bare rocks, and as they grow very rapidly, they have been largely employed in Africa, Australia, and India for fences. It is reported that when an island in the West Indies was divided between the French and English, the boundary was marked by three rows of O. Tuna.

The flowers of Opuntias are not, as a rule, particularly attractive. In many of the kinds they are large and well-formed, but the colours are tawny-yellow, greenish-white, or dull red. These plants cannot, therefore, be recommended for any floral beauty, although it is probable that the same flowers, on plants of less repulsive appearance than Opuntias are, as a rule, would be admired. There are a few exceptions to this in such species as O. Rafinesquii, O. missouriensis, and O. basilaris, which are compact and dwarf, and bear numerous large, brightly-coloured flowers. The fruits of Opuntias, or, at least, some of them, are edible, and to some palates they are very agreeable. We have tasted them, and consider they are mawkish and insipid—not much better than very poor gooseberries. Sir Joseph Hooker has compared them to Pumpkins. They are pear-shaped, with a thick, spine-covered rind, containing green, yellow, or red pulp, with small, hard seeds scattered through it.

The fruit of Opuntia differs in character and structure from the ordinary kind of fruit, such as apples, pears, &c. It consists of a branch, or joint, modified in form, and bearing on its flattened apex a flower, with the ovary buried in a slight depression in the fleshy joint. After becoming fertilised, the ovary grows down into the joint, and, ultimately the whole joint is changed into a succulent, juicy, often coloured "fruit." That this is the case has been proved by planting the unripe "fruit" of Opuntias in pots of sandy soil, and treating them as cuttings, when they have developed buds at the apex and roots at the base, ultimately forming plants.

The vitality in the branches of most of the species is very great, the smallest piece, as a rule, emitting roots and developing into a plant in a comparatively short time. The branches are soft, and easily broken, so that, in gathering the fruits, many pieces are broken off and cast aside; these soon grow into plants, and in a short time an extensive "colony" of Opuntias springs up where previously only one had been. The seeds, too, are a ready means of increase, being distributed by birds and other animals, which eat the fruits. In consequence of this free vegetative character, the Opuntias introduced into some of our colonies have become a pest almost as difficult to deal with as the rabbit scourge in Australia. In English gardens, however, there is no danger of Opuntias getting the upper hand. The adaptability of the majority of the kinds for cultivation under what may be termed adverse conditions for other plants, and the ease with which they may be propagated, render the management of a collection of these plants an easy matter. Amongst other Cactuses, Opuntias have a striking effect, and a selection of them should be grown in even the smallest collections. A few of them may be recommended specially as attractive plants for a sheltered, sunny rockery.

Cultivation.—The cultural requirements of the Opuntias may more conveniently be referred to under the description of each kind.

Propagation.—This entails no exceptional treatment; the numerous seeds contained in each fruit germinate freely if sown in sandy soil, and placed on a shelf in a warm house; and the smallest branches root quickly if planted in pots of open soil and kept in the Cactus-house. Large branches root just as freely as small ones. At Kew an enormous specimen, which had grown tall, and developed a thicket of branches too great for the house where it grew, was reduced most summarily by simply cutting off the head of branches and planting it in the ground where the original specimen had been. In a short time this "cutting" was well rooted, and made better growth than it had before the operation was performed.

As stocks for grafting, many of the more robust kinds of Opuntia are well adapted, and very singular-looking specimens may be obtained by making the most of this fact. One of the crested or monstrous forms, when grafted on a flat-stemmed kind, presents the queerest of appearances, looking like a large green cockscomb growing out of the top of a bladdery kind of stem. Equally odd combinations may be made by grafting a flat-stemmed kind on one whose stem is cylindrical. As all the kinds unite with the greatest ease, a taste for oddities among plants may easily be gratified by making use of Opuntias in this way. The time most favourable for the operation is spring-say, the month of April. For full information on how to graft Cactuses, see Chapter IV., on Propagation.

SPECIES.

O. arborescens (tree-like).—This species is known as the Walking-Stick or Elk-Horn Cactus, from its cylindrical, woody stems being made into very curious-looking walking-sticks (examples of which may be seen in the Museum at Kew), whilst the arrangement of the branches is suggestive of elk horns. Habit erect; joints cylindrical, branching freely, and forming trees from 8 ft. to 30 ft. high. Stems covered with oblong tubercles and tufts of long, needle-like spines, which give the plant a very ferocious aspect. Flowers on the ends of the young branches, 2 in. to 3 in. in diameter, bright purple in colour, developing in June. It is a native of Mexico, &c., and requires greenhouse or stove treatment. The skeletons of this species, as seen scattered over the desert places where it is wild, have a very singular and startling appearance. They stand in the form of trees, quite devoid of leaves, spines, or flesh, and, owing to the peculiar arrangement of the ligneous layers, nothing remains except a hollow cylinder, perforated with mesh-like holes, indicating the points where the tubercles and small branches had been. These skeletons are said to stand many years.

O. arbuscula (small tree).—Another of the cylindrical kinds, with a solid, woody trunk, about 4 in. through, and clothed with smooth, green bark; it grows to a height of 7 ft. or 8 ft. Branches very numerous, slender, copiously jointed, the ultimate joints about 3 in. long and 1/2 in. thick; they are slightly tuberculated, and bear tufts of spines nearly 1 in. long. Flowers 11/2 in. in diameter, produced in June; petals few, greenish-yellow, tinged with red. It is a native of Mexico, and requires stove treatment. A pretty plant, or, rather, a very remarkable one, even when not in flower, the thin branches, with their hundreds of long, whitish spines, being singular. Unfortunately, it is not easily grown.

O. arenaria (sand-loving).—Stems spreading, forming a tuft 3 ft. through and about 1 ft. high. Joints 11/2 in. to 3 in. long, and a little less in width, terete, with very prominent tubercles and numerous tawny bristles; upper spines 1 in. to 11/2 in. long, white, with a yellow point, shorter ones hair-like and curled. Flowers 2 in. in diameter, produced in May. Fruit 1 in. long, bearing a few short spines. Mexico. A strong-rooted plant, which should be grown in very loose, sandy soil. It would probably thrive best when planted out on a stage near the glass in a stove.

O. Auberi (Auber's).—An erect-growing plant, 8 ft. or more high, not unlike O. Ficus-indica in the form of its joints, but with long spines springing from the cushions, whereas the latter has none. The joints are oblong-ovate, glaucous-green, the cushions few and scattered; spines white, flattened, of various lengths. Flowers tawny yellow, small for the size of the plant. A native of Cuba, and requiring stove treatment. Being very brittle, this plant should be supported with stakes.

O. aurantiaca (orange).—A dwarf, cylindrical-stemmed kind, branching freely. Joints short, 3/4 in. in diameter; cushions of reddish spines, one about 1 in. long, the others shorter; bases of spines enveloped in white wool. Flowers bright orange, 2 in. to 3 in. across. This species is a native of Chili, whence it was introduced in 1824. It should be grown in a warm greenhouse all winter, and placed in a sunny position outside during summer.

O. basilaris (branching at the base); Fig. 76.—A dwarf, compact plant, of peculiar habit. Stem short, branching into a number of stout, obovate, often fan-shaped joints, which usually spring from a common base, and curve inwards, suggesting an open cabbage. Joints 5 in. to 8 in. long, about 1 in. thick, covered all over with dot-like cushions of very short, reddish spines, set in slight depressions or wrinkles. Flowers of a beautiful and rich purple colour, about 21/2 in. in diameter, and produced in May. This distinct plant is a native of Mexico, and is of recent introduction. Plants of it may be seen in the Kew collection. It is apparently easily kept in health in an ordinary stove temperature along with other Cactuses. It varies in the form of its joints and in its manner of branching, but it seems never to develop the joints one on the top of the other, as do most Opuntias. This species is certain to become a favourite when it becomes better known.



O. Bigelovii (Bigelow's).—A cylinder-stemmed, tall-growing plant, with a stout, woody stem, bearing a dense head of branches. Joints 2 in. to 6 in. long, 1 in. to 2 in. in diameter, light green, covered with small tubercles and little spine-cushions, with larger spines 1 in. long. When wild, the young joints are often shaken off by the wind, and cover the soil around, where they take root or stick to the clothes of the passers-by like burrs. Flowers not known. A native of Mexico, where it forms a tree 12 ft. high; it requires stove treatment. The skeleton of the trunk is a hollow cylinder, perforated with numerous holes, which occur in a regular spiral. The appearance of a full-grown specimen is very striking, the oval joints, thickly covered with long, needle-like spines, hanging in clusters, more suggestive of spiny fruit than branches.

O. boliviana (Bolivian); Fig. 77.—Stems 1 ft. high, erect, branching, and composed of roundish, pale green joints, with small, round tubercles, and long, white, flexible spines, sometimes as much as 4 in. in length; cushions about 1 in. apart. Flowers 11/2 in. across, yellowish. This is a fat, gouty-looking plant, from Bolivia, requiring stove treatment. It often assumes a yellow hue on the older joints, even when in good health.



O. brachyarthra (short-jointed); Fig. 78.—A dwarf-growing, singular-looking plant, with short, tumid joints from 1 in. to 2 in. long and wide, and nearly the same in thickness. The shortness of the joints, together with their growing on the top of each other, has been not inaptly compared to a jointed finger. Cushions very close together, composed of short, white and yellowish bristles, and stout, terete spines, 1 in. or more long, set on little tubercles. Flowers 1 in. in diameter, with about five sepals, eight or nine petals, and a five-rayed stigma; they are borne on the apices of the topmost joints. This species is worth growing on account of its peculiar stems and the length of its white spines. It is a native of New Mexico, and has been recently introduced to Kew, where it is cultivated among the hardy kinds, and also in the greenhouse.



O. braziliensis (Brazilian).—The peculiar habit and mode of growth at once distinguish this species. It rises with a perfectly straight, erect, slender, but firm and stiff, round stem, to a height of from 10 ft. to 30 ft., tapering from the base upwards, and furnished all the way up with short, horizontal branches, spreading about 3 ft. all round, like an immense candelabrum. Spines long, subulate, very sharp, ash-coloured, in clusters. Joints broadly oblong, margins wavy; they resemble leaves, or the thin, leaf-like joints of a Phyllocactus, with the addition of long, whitish spines on both sides. Flowers 11/2 in. in diameter, lemon-yellow, very freely produced on the younger joints during May and June. Fruit as large as a walnut, spiny, yellow when ripe. This species is a native of Brazil, whence it was introduced in 1816. It may be recommended for large, airy houses, as it grows freely, and forms a striking object when arranged with foliage and flowering plants of the ordinary kind. Its fruits are edible.

O. candelabriformis (candelabrum-shaped).—Stems erect, 5 ft. to 8 ft. high; joints flat, almost circular, about 6 in. in diameter, glaucous-green, densely clothed with numerous cushions of white, bristle-like spines, a few in each cushion being long and thread-like. Flowers not known on cultivated plants. This sturdy species is a native of Mexico, and succeeds well if planted on a little rockery or raised mound in a warm house, where, properly treated, it branches freely, and forms a dense mass of circular joints. It is one of the most useful of the larger Opuntias for cultivation in large houses.

O. clavata (club-shaped).—Stem short; joints club-shaped, 2 in. long and 1 in. wide, narrowed almost to a point at both ends. Cushions 1/4 in. apart, composed of numerous spines, varying from short and bristle-like to 1 in. in length, stout, flattened, and spear-like. Leaves 1/4 in. long. Flowers yellow, 11/2 in. across. Fruit 11/2 in. long, lemon-yellow when ripe, and covered with stellate clusters of white, bristle-like spines. New Mexico, 1854. A stove species, remarkable for the strength and form of its central spines, which are spear or dagger-shaped.

O. cochinellifera (cochineal-bearing); Bot. Mag. 2742.—An erect-growing plant, attaining a height of 9 ft. or more, and branching freely, the older parts of the stem and branches being woody and cylindrical; young joints flat, oblong-ovate, varying in length from 4 in. to 1 ft., deep green, rather soft and watery, spineless, the cushions distant, and sometimes bearing a few very short bristles. Flowers at the extremities of the branches, 11/2 in. long, composed of numerous imbricating, scale-like petals, curving inwards, and coloured crimson. Fruit flat-topped, 2 in. long, red; pulp reddish; seeds black. It is a native of tropical South America, whence it was introduced in 1688. It requires stove treatment, and blossoms in August. This is one of the most useful of the genus, on account of its being the kind chiefly employed in the cultivation of cochineal. It is one of the easiest to manage, requiring only a rather dry atmosphere, plenty of light, and a temperature not lower than 50 degs. in winter. Syn. Nopalea cochinellifera.

O. corrugata (wrinkled).—Stem not more than 2 ft. high; joints cylindrical, wrinkled all over, about 2 in. long, covered with cushions of white hair or bristle-like spines. Flowers 11/2 in. across, reddish-yellow, produced in August. A native of Chili, whence it was introduced in 1824. It may be grown in an ordinary greenhouse, on a shelf near the glass, and exposed to full sunshine.

O. curassavica (Curassoa); Pin-pillow.—Branches spreading; joints cylindrical or club-shaped, dark green, bearing numerous cushions of woolly bristles, and long, white, very sharp-pointed spines. Flowers 3 in. across, greenish-yellow, borne on the young joints in June. Introduced from Curassoa in 1690. A free-growing plant under favourable conditions, and one requiring stove treatment. It has been cultivated in gardens almost as long as any species of Cactus. There are several varieties of it known, differing from the type in habit, length of spine, or shade of colour in the flower.

O. cylindrica (cylindrical).—Stem and joints cylindrical, the latter covered with spindle-shaped tubercles, each one crowned with a tuft of fine, hair-like, whitish spines, one or two in each tuft being stiff, and sharp as needles. The leaves are fleshy, cylindrical, 1 in. or more long, and they remain on the joints longer than is usual in Opuntias. Flowers crowded on the ends of the branches, each 1 in. in diameter, scarlet; they are developed in June. This plant is said to grow to a height of 6 ft. or more in its native habitat, but under cultivation it is rarely seen more than 3 ft. high; it was introduced in 1799. It is handsome and distinct enough to be worth growing. It requires stove or greenhouse treatment, but rarely flowers under cultivation.

O. c. cristata (crested).—A dwarf, cockscomb-like variety, with the leaves and white hairs growing all along the wrinkled top of the comb. It is a very singular example of a "monster" Cactus. It requires stove treatment.

O. Davisii (Davis'); Bot. Mag. 6652.—Stems somewhat horizontal, not exceeding 11/2 ft. in height; joints 4 in. to 6 in. in length, and about 1/2 in. in thickness; wood dense, and hard when old; tubercles not prominent, bearing cushions of very slender bristles, forming a kind of brush, from amongst which the spines spring. The longest spines are 11/2 in., and they are covered with a loose, glistening sheath. Flowers 2 in. in diameter, greenish-brown. The plant is a native of New Mexico, and was introduced in 1883. It forms a compact, shrubby little plant if grown in an intermediate house during winter, and placed in the open in full sunshine during summer. It was flowered for the first time in England in 1883, and although not what we should call an attractive plant, in America it is described as being "a well-marked and pretty species." It is named after Jefferson Davis, the American statesman.

O. decumana (great-oblong). This is the largest-growing species in cultivation. At Kew it is represented by a plant 12 ft. high (it would grow still taller if the house were higher). It has a hard, woody, brown-barked stem, bearing an enormous head of very large, elliptical, flat joints, 12 in. to 20 in. long, and about 1 ft. broad, smooth, grey-green, with a few scattered cushions of very tiny bristles, and sometimes, though rarely, a spine or two. Flowers large, orange-coloured, produced in summer. Fruit oval, 4 in. long, spiny, brownish-red, very watery when ripe; flesh red, sweet. A native of Brazil, and requiring stove treatment. This is said to be what is known in Malta as the Indian Fig. The plant is chiefly interesting here on account of the extraordinary size of the joints.

O. diademata (diademed).—A small, remarkable, and extremely rare little species, with a short, erect stem, composed of globose, superposed joints, grey-green in colour, and very succulent. The topmost joint is pear-shaped, with a tuft of whitish hair and spines on the apex, out of which the new growth pushes. Cushions large, about 1 in. apart, furnished with a tuft of short, grey hairs and short spines, with a large one at the base. The character of this large spine is exceptional, being broad, flat, cartilaginous, whitish, and curving downwards. On healthy large examples these spines are 2 in. long, and nearly 1/4 in. wide at the base. Flowers and fruit not known. Native of Mendoza (La Plata). This little plant requires to be cultivated in a warm greenhouse or stove, but it grows very slowly. It is certainly a most interesting Cactus; examples of it may be seen at Kew, where there is a plant which, although over ten years old, is only 4 in. high. Syns. O. platyacantha and Cereus syringacanthus.

O. Dillenii (Dillenius'); Fig. 79.—An erect-growing, robust species, attaining a height of 15 ft., with flattened, ovate joints, about 5 in. long by 3 in. broad. Cushions composed of short, white, hair-like bristles, and numerous long, stout, yellow spines. Flowers yellow, tinged with red, 4 in. in diameter, freely produced on the ends of the youngest joints all summer. Fruits similar to those of O. Ficus-indica. A native of the West Indies, now naturalised in all warmer parts of the world. In India it is so plentiful and widespread that Roxburgh, an Indian botanist, said it was a native. In India, its fruits are eaten by the poor natives, and it is often planted as a hedge. It is also a great pest in the open lands of that country, and large sums are annually expended in cutting it down and burying it. This species, which requires warm greenhouse treatment, is also employed in the cultivation of cochineal.



O. echinocarpa (spiny-fruited).—A low, straggling shrub, not exceeding 11/2 ft. in height. Joints cylindrical, from 1 in. to 3 in. long, less than 1 in. thick. Cushions of rather coarse bristles and numerous spines, from 1/2 in. to 1 in. in length. Flowers 2 in. in diameter, yellow, produced in summer. Fruit short, depressed, almost saucer-shaped, and bearing spines nearly 1 in. long. A native of Colorado, &c. It requires stove treatment. The variety major has stems 4 ft. high, joints 8 in. to 10 in. long, and long, sheathed spines. This species is closely related to O. Bigelovii and O. Davisii.

O. Emoryi (Emory's).—A prostrate, spreading plant, less than 11/2 ft. high. Joints cylindrical, curved, 4 in. long, 11/2 in. thick. Tubercles very prominent, longitudinally attached to the stem, the apices crowned with pea-shaped cushions of short bristles, and numerous radiating spines, some of which are fully 2 in. long, very strong and needle-like. Flowers 21/2 in. in diameter, sulphur-yellow, tinged with purple, produced in August and September. Fruit 21/2 in. long and 1 in. thick, covered with cushions of bristles and spines. A native of Mexico, on dry, sandy soils, where its prostrate stems, clothed with powerful spines, form a hiding-place for the small animals, snakes, &c. Stove or warm greenhouse treatment is best for this species.

O. Engelmanni (Engelmann's).—A stout, coarse-looking plant, 6 ft. high, with woody stems and large, flat, green joints, 1 ft. long and 9 in. in diameter. Cushions 11/2 in. apart, composed of coarse bristles, and one or two spines over 1 in. long, and pointing downwards. Flowers 3 in. in diameter, yellow, produced in May and June. Fruit nearly round, 2 in. long, purplish both in rind and pulp, the latter rather nauseous to the taste. Mexico. This is a greenhouse plant which grows freely and flowers annually under cultivation. It is very similar to O. monacantha, a much better known species. According to American botanists, it is probably the most widely spread of the whole Cactus tribe.

O. Ficus-indica (Indian Fig); Fig. 80.—Branches erect, 8 ft. to 12 ft. high; joints flat, oval or obovate, about 1 ft. long by 3 in. in width, and 1 in. in thickness. Stems hard and woody with age. Cushions 11/2 in. apart, composed of short, yellowish bristles, and very rarely one spine. Flowers 3 in. to 4 in. across, sulphur-yellow, produced all through the summer. Fruit 3 in. to 4 in. long, pear-shaped, covered with tufts of bristles, white, yellow, or red when ripe. It is a native of Central America, whence it was introduced about 300 years ago. It is now widely spread, in tropical and temperate regions all over the world. In many parts it is cultivated for the sake of its fruits, which in some of our colonies are used for dessert. In England it must be protected from damp and cold; it is, therefore, best cultivated in a sunny greenhouse during winter, and placed outside in a position exposed to full sunshine all summer. Tenore, an Italian botanist, named this species O. vulgaris, and this mistake has led others to consider the North American O. vulgaris (true) and O. Ficus-indica as one and the same species.



O. filipendula (hanging filaments); Fig. 81.—Stems prostrate, about 1 ft. high, spreading; joints flat, round or oval, about 3 in. long, often less, milky-green in colour. Cushions 1/2 in. apart, composed of a little tuft of white woolly hair, a cluster of erect, rather long bristles, like a small shaving-brush, and all pointing upwards; spines usually only one in each cushion, and this is slender, deflexed, white, and from 1 in. to 2 in. long. Sometimes the joints are wholly spineless. Flowers 21/2 in. in diameter, purplish, very handsome, produced in May and June. Fruit not known. The roots of this species bear tubers often 1 in. in thickness, and several inches in length, and these tubers will grow into plants if severed and planted. It requires stove treatment. Native country, Mexico.



O. frutescens (shrubby).—A thin-stemmed, copiously-branched species. Joints almost continuous, like ordinary branches, from 2 in. to 6 in. long, the thickest not exceeding 1/4 in. Cushions on raised points or tubercles, each consisting of a small tuft of hair, inclosed in a row of bristles, and one long, central spine, often exceeding 2 in. in length. When young, the spines are inclosed in a thin, bony sheath. Flowers scattered along the younger branches, 1 in. across, greenish-yellow, borne in June. Fruit 1 in. long, pear-shaped, smooth, scarlet, with tufts of bristles all over it, and a depression in the apex. Mexico. This forms an interesting pot-plant when properly cultivated. It should be grown in a warm greenhouse.

O. Grahami (Graham's).—This is one of several species of Opuntia which are remarkable in having thick, fleshy roots, not unlike those of the Dahlia. The joints are 2 in. long and 1 in. in diameter, cylindrical, with adpressed tubercles, 1/2 in. or more long, each tubercle bearing a tuft of long, straight, radiating spines. Flowers 2 in. across, yellow, borne on the ends of the ripened joints in June. Fruits 11/2 in. long and 3/4 in. wide, covered with stellate clusters of short, bristle-like spines. This plant is a native of Mexico, and is a recent introduction. From the nature of its roots, which are no doubt intended to serve as reservoirs for times of extreme drought, it should be grown in well-drained, sandy soil, and kept quite dry all winter. It requires stove treatment.

O. horrida (horrid).—An erect, stout-stemmed plant, with flattened, green joints, about 5 in. long by 3 in. wide. Cushions 1 in. apart, composed of short, reddish bristles, and long, tawny red spines, about eight in each cushion, and of a peculiarly ferocious appearance—hence the specific name. The stoutest spines are 3 in. long, and are sharp and strong as needles. This species (which is probably a native of Mexico) is deserving of a place in collections of Cactuses because of the character of its spines. Probably it is only a variety of O. Tuna. It requires warm-house treatment.

O. hystricina (porcupine-like).—This beautiful species was discovered in the San Francisco Mountains mixed with O. missouriensis, to which it is nearly allied. It is spreading in habit, the joints 3 in. to 4 in. long and broad; cushions 1/2 in. apart, rather large, with numerous spines, varying in length from 1/2 in. to 4 in., and short, yellowish bristles. Flowers large, yellow. Fruit 1 in., long, spiny. This plant is not known in English collections, but it is described by American botanists as being attractive and a free grower. As it is found along with O. missouriensis, it ought to prove hardy in England.

O. leptocaulis (slender-stemmed).—This little Mexican species is chiefly remarkable for its fragile, numerous, twig-like joints, thickly dotted with tubercles and numerous spirally-arranged cushions of reddish bristles, with long, grey spines. It does not flower under cultivation. Requires stove treatment.

O. leucotricha (white-haired).—An erect-stemmed kind, with flattened joints, ovate or oblong in shape, and bearing numerous cushions, 1/2 in. apart, of short bristles, with a large, central spine, and a few others rather shorter. When young these spines are rigid and needle-like; but as they get older they increase in length, and become soft, and curled like stiff, white hair. Young plants are noticeable for their small, subulate leaves of a bright red colour, whilst old examples are almost as interesting as the Old Man Cactus (Pilocereus senilis), the long, white, hair-like spines of the Opuntia hanging from the older joints in much the same manner as they do from the upper part of the stem of the Pilocereus. Flowers yellow, produced in June. This species is a native of Mexico, and requires stove treatment. Seeds of this, and, indeed, of a large proportion of the cultivated Opuntias, may be procured from seedsmen, and as they germinate quickly, and soon produce handsome little plants, a collection of Opuntias is thus very easily obtained.

O. macrocentra (large-spurred).—A flat-jointed species, growing to a height of 3 ft.; the joints large, almost circular, thinly compressed, and usually purplish in colour. Cushions about 1 in. apart, with spines often 3 in. long, of a greyish colour, and generally pointing downwards. Flowers 3 in. across, bright yellow; they are developed in May and June, on the upper edges of the youngest joints. This plant is a native of Mexico; it is at present rare, but the unusual colour of the joints, its compact, freely-branched habit, the extraordinary length of its spines, and the size of its flowers, ought to win for it many admirers. It is easily grown if kept in an intermediate house. Plants of it may be seen in the Kew collection.

O. macrorhiza (large-rooted); Figs. 82, 83.—In this Texan species we have a combination of the principal characters for which the genus Opuntia is remarkable: The thick, fleshy roots, which are a supposed source of food, and which look like potatoes; the cylinder-shaped older stems, and the flattened, battledore-like joints; the tufts of bristles on the stems, and deciduous, longer spines on the joints; the large, beautiful, yellow flowers; and the small leaves on the newly-formed joints. In habit and flowers this kind resembles O. Rafinesquii; and if not quite hardy in England, it is nevertheless sufficiently so to thrive in any sunny position where it would be protected from frost and excessive wet. The accompanying illustrations represent the characters of this species so well that further description is not needed. The flowers are developed in early summer.



O. microdasys (small, thick).—This is a handsome little Mexican plant. Its flattened joints, which are nearly circular in outline, are thickly covered with little cushions of bright orange-yellow bristles, the cushions being so close together that the short bristles almost hide the green joints from view. The stems are semi-decumbent, and they branch somewhat freely. Flowers not seen. It thrives in a warm greenhouse temperature. The best examples of this pretty Opuntia are grafted on a robust-growing kind, the stock being about 1 ft. long, and the scion forming a compact head of pretty, healthy-looking joints. Treated in this way, this species is most interesting and attractive. It may also be grown on its own roots. There is a variety of it, named rufida, in which the bristles are reddish-brown.

O. missouriensis (Missouri).—A stout, prostrate kind, forming large, spreading masses under favourable conditions. Joints broad, flattened, obovate, about 4 in. long by 2 in. wide, light green; spine-cushions less than 1 in. apart, and composed of numerous small, white spines, with from one to four longer ones; these latter fall away when the joints get old. Leaves very short, with a little wool about their bases. Flowers 3 in. in diameter, appearing from May onwards; petals yellow, dashed with rose, sometimes wholly rose-coloured or brick-red. Stamens deep red; pistil yellow, with a conical stigma. Fruit nearly round, spiny, about 2 in. long. A native of Wisconsin, and westward to the San Francisco Mountains; introduced in 1814. This species is as hardy as O. Rafinesquii, and thrives under similar treatment. It has stood 22 degs. of frost without suffering, requiring only protection from rain in winter. In North America it forms large, spreading masses on gravelly hillsides, and is much dreaded by travellers, and especially by horses; there it is usually covered with snow from Christmas to the following May.

O. monacantha (one-spined).—A tall, robust plant, not unlike O. Dillenii in general habit. It has flat, large joints, oblong or ovate in outline, rather thinly compressed, and bearing grey cushions over 1 in. apart, with a solitary spine, 11/2 in. long, springing from the centre of each cushion, and pointing downwards. Flowers sulphur-yellow, 21/2 in. across, borne on the last-ripened joints in May, and abundant on well-grown plants. Fruits ovate, 2 in. long, green, with tufts of short, brown bristles; pulp edible. The species is a native of Brazil, but is now common in many tropical and sub-tropical countries. It is a free-growing kind, soon forming a large specimen if planted in a bed of old brick-rubble, or other light, well-drained soil, and kept in warm greenhouse temperature.

O. nigricans (blackish); Bot. Mag. 1557.—Stem stout, erect, becoming hard and woody when old. Joints flat, oval in outline, 5 in. to 8 in. long. Cushions 11/2 in. apart, composed of short reddish-brown bristles and two or three long stout spines, which are yellow when young, but almost black when ripe. Flowers produced on the young, ripened joints, orange-red, about 3 in. across and developed in August and September. Fruit pear-shaped, rich crimson when ripe. Introduced from Brazil in 1795. This well-marked species thrives in a warm greenhouse. It branches freely, and has a healthy aspect at all times. It is represented at Kew by very large specimens; one of them, which was recently cut down, had a stem 12 ft. high and an enormous head of dark, green joints. Its head was planted as a cutting.

O. occidentalis (Western).—Stem stout, woody, with innumerable branches, wide-spreading, often bent to the ground. Joints 9 in. to 12 in. long by about 6 in. broad, flattened, as many as 100 on one plant. Cushions nearly 2 in. apart, with small, closely-set bristles and straight spines from 1/2 in. to l1/2 in. long. Flowers produced in June on the ripened joints, nearly 4 in. in diameter, orange-yellow. Fruit 2 in. long, "very juicy, but of a sour and disagreeable taste." This is an exceptionally fine plant when allowed sufficient space to develop its enormous branches and joints; it is a native of the Western slopes of the Californian mountains. It should be planted in a bed of rough, stony soil, in a dry greenhouse. Possibly it is hardy, but it does not appear to have been grown out of doors in England.

O. Parmentieri (Parmentier's).—Stem erect. Joints cylindrical, "like little cucumbers." Cushions about 1 in. apart, arranged in spiral rows, and composed of short, reddish bristles, with two or three straw-coloured spines, 1 in. long. Flowers reddish, small. The plant is a native of Paraguay, and is rarely heard of in cultivation. It requires stove treatment.

O. Parryi (Parry's).—Stem short. Joints club-shaped, 4 in. to 6 in. long, very spiny, the cushions elevated on ridge-like tubercles. Bristles few, coarse, and long. Spines very numerous, varying in length from 1/4 in. to 11/2 in.; central one in each cushion much the broadest, and flattened like a knife-blade, the others being more or less triangular. Flowers yellowish-green, on the terminal joints, which are clothed with star-shaped clusters of bristle-like spines, the flowers springing from the apex of the joint, and measuring 11/2 in. across. A native of Mexico, where it grows on gravelly plains. This distinct plant is in cultivation at Kew, in a warm greenhouse, but it has not yet flowered.

O. Rafinesquii (Rafinesque's); Fig. 84.—A low, prostrate, spreading plant, seldom exceeding 1 ft. in height, the main branches keeping along the ground, the younger ones being erect. The latter are composed of flat, obovate joints, 4 in. to 5 in. long by 3 in. in width, fresh green in colour; spines very few, mostly only on the upper edge of the last-made joints, single, or sometimes two or three from each spine-cushion, 1 in. long, straight, whitish, soon falling off; cushion composed of very fine reddish bristles and whitish wool; leaves very small, falling early. The branches become cylindrical and woody with age. Flowers 2 in. to 4 in. in diameter, bright sulphur-yellow, with a reddish tint in the centre; in form they are like a shallow cup, the numerous stamens occupying the middle. They are produced in great abundance on the margins of the youngest joints, as many as fifty open flowers having been counted on a single specimen at one time. Fruit pear-shaped, 11/2 in. to 2 in. long, naked, edible, somewhat acid and sweetish. The flowering season is from July to September; the native country, Wisconsin to Kentucky, and westward to Arkansas and Missouri. This species, introduced about twenty years ago, has only recently been brought prominently before English gardeners. It is a very ornamental and interesting plant for outdoor cultivation, and when once established gives no trouble. For the first year or two after planting it requires watching, as, until the basal joints harden and become woody, they are liable to rot in wet weather. A large-flowered form, known as grandiflora, is cultivated in American gardens.



O. rosea (rose-coloured); Fig. 85.—Stem erect, branching freely. Joints varying in length from 2 in. to 6 in., not flattened, with ridge-like tubercles, bearing on their points small cushions of very fine bristles and tufts of pale yellowish spines about 1/2 in. long, and all pointing upwards. Flowers on the ends of the ripened growths of the year, usually clustered, 2 in. across, bright rose-coloured; they are developed in June. A rare species from Brazil, and one which, as the illustration shows, is both distinct and handsome enough to be classed amongst the most select. It requires a stove temperature.



O. Salmiana (Prince Salm-Dyck's).—Stem erect, branching freely, the branches at right angles to the stem. Joints from 1 in. to 6 in. long, cylindrical, smooth, 1/2 in. in diameter, clothed with small cushions of soft, short bristles, and one or two longish spines. Flowers produced in September, 2 in. across, yellow, streaked with red, of short duration. Fruit egg-shaped, 1 in. long, crimson. This species is a native of Brazil, whence it was introduced in 1850. It requires to be grown in an intermediate house. It is a charming little Cactus, and quite exceptional among Opuntias in the colour and abundance of its flowers, and in the rich colour of its numerous fruits, which usually remain on the plant several months. The plant, too, has the merit of keeping dwarf and compact. The small joints separate very easily from the branches, and every one of them will root and grow into a plant. There is something very remarkable in the development of the fruits of this kind. A small branch, or joint, grows to its full length, and a flower-bud appears in the apex. If examined at this stage, it will be seen that the ovary occupies only a very shallow cavity in the top of the branch. After flowering, this ovary grows into the branch, and ultimately the whole branch is transformed into a pulpy fruit, with the seeds scattered all through the pulp. This peculiarity is well shown in O. salmiana, and the development of the fruit can be very easily watched. Many of the small branches do not flower, although they change to a red colour like the fruits.

O. spinosissima (very spiny).—Stem erect, woody. Joints very flat and thin, deep green, ovate or rotund, from 6 in. to 1 ft. long. Cushions 1 in. apart. Bristles very short. Spines in clusters of about five, the longest 2 in. in length, brownish-yellow. Flowers reddish-orange, small, usually only 2 in. across, produced in June. A native of South America; naturalised in many parts of the Old World. The stem becomes cylindrical with age, and sometimes is devoid of branches for about 5 ft. from the ground. The plant requires stove treatment. Probably this kind is only a form of O. Tuna.

O. subulata (awl-shaped).—Stem erect, cylindrical, even below, channelled and tubercled above, about 2 in. in diameter. Joints long and branch-like, with tufts of short, white hair on the apices of the tubercles, and one or two white, needle-like spines from 1/2 in. to 1 in. long. At the base of each tuft, from the apex to 1 ft. or more down the younger branches, there is a fleshy, green, awl-shaped leaf, from 2 in. to 5 in. long. Ultimately the leaves and spines fall away, the tubercles are levelled down, and the mature stem is regular and cylindrical, with tufts of white setae scattered over it. Flowers small, produced in spring; sepals 2 in. long, green, deciduous; petals small, dull purple, usually about eight in each flower. Fruit pear-shaped, 4 in. long; seeds very large, nearly 1/2 in. long and wide. This handsome South American species was the subject of an interesting communication to the Gardeners' Chronicle, in 1884, from Dr. Engelmann. It had previously been known as a Pereskia from the fact of its leaves being persistent and very large. In its leaves, flowers, and seeds, O. subulata is one of the most interesting of the genus. It is easily grown in a warm greenhouse, and deserves a place in all collections of Cactuses.

O. Tuna (native name); Fig. 86.—An erect-stemmed, flat-jointed, robust-growing species. Joints ovate, 4 in. to 9 in. long, with cushions 1 in. apart, composed of short, fulvous bristles, and several long, needle-shaped, unequal, yellowish spines. Flowers borne on the upper edges of the last-ripened joints, 3 in. across, reddish-orange, produced in July. Fruit rich carmine, about 3 in. long, pear-shaped. The plant is a native of the West Indies, &c., and was introduced in 1731. It has already been stated, under O. spinosissima, that there is a close similarity between that species and O. Tuna. We suspect, also, that O. nigricans is another near relation of these two. They are much alike in all characters, and they require the same treatment. O. Tuna has been seen as much as 20 ft. in height.



O. tunicata (coated-spined).—Stem sub-erect, cylindrical. Joints club-shaped, variable in length, about 2 in. in diameter. When young the surface is broken up into numerous oblong tubercles, each bearing a small cushion of whitish, short hairs, and about half a dozen white spines, unequal in length, the longest stout, and inclosed in a hard sheath, which becomes broken and ragged when old. Flowers not known. A native of Mexico, and introduced in 1840. It requires stove treatment.

O. vulgaris (common); Bot. Mag. 2393.—A low, prostrate, spreading plant. Joints short, oval, flattened, thicker than in O. missouriensis, 3 in. long by about 2 in. broad. Spine-cushions 3/4 in. apart; tufts very small, with, occasionally, a long spine. Leaves fleshy, very small. Flowers 2 in. across, pale sulphur-yellow. Fruits nearly smooth, 11/2 in. long, brown when ripe, with a strong disagreeable odour. The flowers are produced freely in June. The plant grows wild in Mexico, and extends up to New York, usually near the coast. It is now common in many parts of Europe, where it has become naturalised. In Madeira it has taken possession of all waste land, and is perfectly at home there. In England it was cultivated by Gerard nearly 300 years ago. It grows rapidly if planted in stony soil, in a position exposed to full sunshine, where it will creep along the ground, and root all along its stems, which rarely get elevated more than 6 in. from the ground. This species and O. Ficus-indica are confused by some authors, owing, no doubt, to the name O. vulgaris having been given by a botanist to the latter, which is a much larger and very different-looking plant. O. vulgaris is capable of withstanding our winters out of doors.

O. Whipplei (Captain Whipple's).—Stem usually prostrate, with slender, elongated branches, which are cylindrical when old, broken up into short joints when young. Joints varying in length from 2 in. to 1 ft., less than 1 in. in diameter. Cushions small, round. Spines white, variable in number, and arranged in tufts on the ends of the tubercles, one being 1 in. long, the others shorter. Flowers nearly 2 in. in diameter, red, borne in a cluster on the ends of the last-ripened joints in June. Fruit 1 in. long, with a cavity in the top. A compact, Mexican species, with crowded branches, and very free-flowering. It requires stove treatment. O. Whipplei is related to O. arborescens, from which, however, it is easily distinguished by the latter having a stout central spine and numerous radiating ones.

Of the 150 species of Opuntia known, about one-third have been selected for description here, and amongst these will be found all the best-marked kinds in the genus, and most of those of which we have any knowledge. Botanists find good specific characters in the size and structure of the seeds, in the character of the fruits, &c.; but for horticultural purposes these are of little or no value.



CHAPTER XV.

THE GENUS PERESKIA.

(Named in honour of Nicholas F. Peresk, a botanist of Provence.)

The thirteen species included in the genus Pereskia differ so markedly from all other kinds of Cactus, that at first sight one can scarcely believe they are true Cactuses, closely related to Cereus and Epiphyllum. They have erect or trailing stems and branches, and usually form dense, large bushes; the branches are woody and thin, and bear large, laurel-like leaves, which remain on the plants several years—so that they may be termed evergreen. They have, however, the spine-cushions, the tufts of woolly hair and stout spines, and the floral characters which distinguish Cactuses from other plants; they are also succulent, the leaves and young branches being soft and fleshy. They appear to have the same peculiar provision for enabling them to bear long periods of drought without suffering that characterises the more familiar forms of Cactuses. The development of the spines in this genus is different from what takes place in all other spiny plants of this order. In the latter the spines are stoutest and most numerous on the younger parts of the plant, the older or woody parts being either spineless, through having cast them, or much less spiny than when they were younger. Thus, in Opuntia we find few or no spines on the old parts of the stems of even such species as O. horrida, O. nigricans, &c. In Echinocactus, too, the spines about the base of old plants are much fewer, if not entirely cast off, than on the upper part. In Pereskia the contrary is the case. Taking P. aculeata as an example, this is best known in gardens as having branches about as thick as a goose-quill, with ovate leaves, at the base of which there is a pair of curved spines, 1/4 in. long, and shaped like cats' claws. But this plant when it gets old has a stem 3 in. in diameter, and clothed down to the ground with cushions of spines fixed firmly in the bark, each cushion composed of from twenty to fifty spines, and each spine 1 in. or more in length. From two to six new spines are developed in the centre of each healthy cushion annually. It would be absolutely impossible for any animal to climb an old stem of a Pereskia. In P. Bleo the spines are 2 in. long, and the cushions are much larger.

The flowers of Pereskias are borne singly or in panicles, at the ends of the young, ripened branches. In shape, each flower may be compared to a single Rose, the petals being flat and spreading, and the numerous stamens forming a compact cluster in the centre. The stigma is erect, and divided at the top into four or more rays. The fruit is a berry shaped like a Gooseberry, and covered with minute clusters of short bristles.

All the species are found in tropical America and the West Indies.

Cultivation.—Although several of the kinds of Pereskia are sufficiently ornamental to be deserving of a place in gardens as flowering plants, yet they are rarely cultivated—in England, at least —for any other purpose than that of forming stocks upon which Epiphyllums and other Cacti are grafted. Only two species are used, viz., P. aculeata and P. Bleo, the former being much the more popular of the two; whilst P. Bleo, on account of the stoutness of its stems, is employed for only the most robust kinds of grafts.

Propagation.—Both the above-named species may be propagated to any extent, as every bit of branch with a leaf and eye attached is capable of rooting and soon forming a stock. The practice among those who use Pereskias as stocks for Epiphyllums is as follows: Cuttings of P. aculeata are planted in sandy soil, in boxes, and placed on a shelf in a stove till rooted. In about a month they are ready to be planted singly in 3 in. pots, any light soil being used; and each plant is fastened to a stake 1 ft. long. They are kept in a warm, moist house, all lateral shoots being cut away, and the leader encouraged to grow as tall as possible in the year. From December the plants are kept dry to induce the wood to ripen, preparatory to their being used for grafting in February. Stocks 9 in. or 1 ft. high are thus formed. If taller stocks are required, the plants must be grown on till of the required length and firmness. Large plants may be trained against a wall or along the rafters in a warm house; and when of the required size, the branches may be spurred back, and Epiphyllums, slender Cereuses, and similar plants, grafted upon them. In this way very fine masses of the latter may be obtained in much less time than if they were grown from small plants.

SPECIES.

P. aculeata (prickly); West Indian or Barbados Gooseberry.—Stem woody, more or less erect, branching freely, and forming a dense bush about 6 ft. high. Young branches leafy; old ones brown, leafless, clothed with large cushions of long, stout, brown spines, sometimes 2 in. in length. Leaves alternate, with very short petioles, at the base of which is a pair of short spines, and a small tuft of wool in the axil; blade 3 in. long by 2 in. broad, soft, fleshy, shining green. Flowers semi-transparent, white, in terminal panicles; sepals and petals 3/4 in. long by 1/4 in. wide; stamens in a large, spreading cluster, white, with yellow anthers. Ovary covered with small cushions of short bristles, with sometimes a solitary spine in the centre of each cushion. Fruit 1 in. long, egg-shaped, red, edible. There is a large plant of this in the Succulent House at Kew which flowers almost annually, but it has never ripened fruits. In the West Indies it is a very common shrub, whilst at the Cape of Good Hope it is used for fences—and a capital one it makes.

P. a. rubescens (reddish).—This variety has narrower, longer leaves, which are glaucous-green above and tinged with red below; the spines on the old stems are shorter and more numerous in each cushion. This requires the same treatment as the type.

P. Bleo (native name); Fig. 87.—A stout, branching shrub, having an erect stem, 3 in. or more in diameter, with green bark and very large cushions of spines; cushion a round, hard mass of short, woolly hair, from which the spines—about fifty in each cushion—radiate in all directions; longest spines 2 in. or more in length; one or two new ones are developed annually, and these are bright red when young, almost black when ripe; young branches 1/4 in. to 1/2 in. in diameter. Leaves 1/2 in. apart, 3 in. to 6 in. long by 1 in. to 2 in. wide, oblong, pointed, with short petioles, and a small tuft of short, brown hair, with three or more reddish spines, in the axil of each. Flowers on the ends of the young, ripened branches, clustered in the upper leaf-axils, each flower 2 in. across, and composed of a regular circle of rosy-red petals, with a cluster of whitish stamens in the centre. They remain on the plant several weeks. Native of New Grenada. Probably P. grandiflora is the same as this, or a slightly different form of it. A large specimen may be obtained in a year or two by planting it in a well-drained bed of loam, in a warm, sunny house. It blossoms almost all summer if allowed to make strong growth. Pretty little flowering plants may be had by taking ripened growths from an old plant, and treating them as cuttings till rooted. In the following spring they are almost certain to produce flowers. Plants 1 ft. high, bearing a cluster of flowers, are thus annually obtained at Kew. Fig. 87 represents a short, stunted branch, probably from a specimen grown in a pot. When planted out, the leaves and spine-cushions are farther apart.



P. zinniaeflora (Zinnia-flowered); Fig. 88.—Stem erect, woody, branching freely, the branches bearing oval, acuminate, fleshy, wavy-edged, green leaves, with short petioles, and a pair of spines in the axil of each. Spine-cushions on old stems crowded with stout, brown spines. Flowers rosy-red, terminal on the ripened young shoots, and composed of a whorl of broad, overlapping petals, with a cluster of stamens in the centre, the whole measuring nearly 2 in. across. This species is a native of Mexico; it grows and flowers freely if kept in a warm house.



CHAPTER XVI.

THE GENUS RHIPSALIS.

(From rhips, a willow-branch; referring to the flexible, wand-like branches of some of the kinds.)

About thirty species of Rhipsalis are known, most of them more peculiar than ornamental, although everyone is in some way interesting. They are remarkable for the great variety in form and habit presented by the different kinds, some of them much less resembling Cactuses than other plants. Thus, in R. Cassytha, the long, fleshy, whip-like branches and white berries are very similar to Mistletoe; R. salicornoides, with its leafless, knotty branches, resembles a Salicornia, or Marsh Samphire; another is like a Mesembryanthemum; and so on. The flowers are usually small, and composed of numerous linear sepals and petals, arranged more or less like a star, with a cluster of thin stamens in the centre, and an erect, rayed stigma. In the flat-jointed kinds, the flowers are developed singly, in notches along the margins of the young, ripened joints; in the knotted, Samphire-like kinds, they are borne on the ends of the branches; and in those with short, fleshy, leaf-like joints, they are usually placed on what appear to be flower-joints. Although the branches of these plants are usually altogether unlike the rest of the Order, yet occasionally they develop joints which are furrowed, and bear clusters of spines exactly as in the commoner forms of Cactuses.

The geographical distribution of Rhipsalis is exceptional. It is the only genus of Cactuses that has representatives in the Old World, excluding, of course, those which have been introduced by man. The bulk of the kinds of Rhipsalis occur in Central and South America, and the West Indies; but one—viz., R. Cassytha—is also found in Africa, Mauritius, Madagascar, and Ceylon, as well as in tropical America. Several other species are found in Madagascar, some of them only recent discoveries. The occurrence of similar or even identical plants in tropical America and Madagascar has its analogy in the Animal Kingdom as represented in the two countries.

Cultivation.—All the species appear to grow well and flower freely under cultivation, the slowest grower being, perhaps, R. sarmentacea. In their natural homes they are invariably found either on trees or rocks, seldom or never on the ground; but in greenhouses they may be grown in pots, a few being happiest when suspended near the glass. They do not like bright sunshine, nor should they be kept in a very shaded, moist position. There is a good collection of kinds in the Succulent-house at Kew.

Propagation.—Seeds of Rhipsalis ripen freely, and these, if sown on sandy soil, and placed on a shelf in a warm house, germinate in a few days. The development of the seedlings is exceptionally interesting, as the vegetative organs of all the kinds are very similar, and Cactus-like; the gradual transition from this character to the diverse forms which many of the species assume when mature is quite phenomenal. Cuttings will strike at almost any time, if planted in sandy soil and kept in a close, warm house till rooted. Some of the kinds thrive best when grafted on to a thin-stemmed Cereus. Treated in this way, R. sarmentacea makes 6 in. of growth in a season; whereas, on its own roots it would take about five years to grow as much.

The following is a selection of the species cultivated in gardens. The genus Lepismium is now included in Rhipsalis.

SPECIES.

R. Cassytha (derivation not known).—A pendent shrub, 4 ft. or more high, growing on rocks and the mossy trunks of trees. Branches numerous, flexuous, with small branchlets or joints springing from the ends in clusters, smooth, round, the thickness of whipcord, leafless, with numerous brown, dot-like marks scattered over the surface; under a lens these dots are seen to be tufts of very fine hairs. Flowers on the sides of the young branches, small, greenish-white, short-lived; they are developed in September, and are succeeded by white berries, exactly like those of the Mistletoe, whence the name Mistletoe Cactus, by which this species is known. An interesting and easily-grown warm greenhouse plant, native of tropical America, Africa, &c. It was introduced in 1758.

R. commune (common); Bot. Mag. 3763.—Stem straggling, branching freely, growing to a length of several feet. Branches jointed; joints varying in length, triangular, the angles compressed, and notched along the margins; notches regular, and bearing tufts of whitish hair. Strong plants produce joints over 1 in. in width. Flowers white, tinged with purple, springing singly from the notches, and composed of eight to twelve sepals and petals. Stamens and stigma erect, white, the latter four-rayed. This species is a native of Brazil, and was introduced in 1830; Flowering-season, October to December. It may be grown in a warm greenhouse, and treated as a basket-plant or as a small pot-shrub. Syn. Lepismium commune.

R. crispata (curled).—Stem branching freely. Branches jointed and flat, like Epiphyllum. Margins of joints notched, and slightly curled. Flowers small, white, produced singly, in November and December, in the notches on the younger joints. Fruits white, pea-like, rather rarely ripened. A free-growing, compact stove shrub, with a bright green, healthy appearance. The similarity of its branches to Epiphyllum led to its being included in that genus by Haworth.

R. c. purpurea (purple).—This variety has larger, broader joints, which are bronzy-purple in colour.

R. fasciculata (cluster-branched); Bot. Mag. 3079.—Stems terete, as thick as a goose-quill. Branches usually in clusters, and sometimes jointed, green, with small red dots and little tufts of fine, hair-like bristles. Flowers white, produced in March, springing irregularly from the older branches, small, star-like. Fruit a white berry. From its habit of growing on trees, and the character of its stems and fruit, this plant has been called parasitical. It is, however, only indebted to the tree on which is grows for moisture, for it thrives if planted in a pot or basket in ordinary soil, and kept in a stove temperature. It is a native of Brazil, and was introduced in 1831.

R. floccosa (woolly).—Stems as in R. Cassytha, but thicker, longer, and with the branchlets in compact clusters on the ends of the long, arching branches. The dots marking the position of the microscopic hair-tufts are in small depressions. Flowers and fruit as in R. Cassytha, of which this might reasonably be called a variety. This species requires warm-house temperature.

R. funalis (cord-like); Fig. 89.—Stem straggling, branched. Branches numerous, composed of long, terete joints, rather thicker than a goose-quill, glaucous-green, slightly roughened on the surface, with depressions for the dot-like cushions. Branchlets usually fascicled and spreading. Flowers white, produced in spring, on the sides of the young joints, 1 in. across, large for the genus. Introduced from Central America about 1830. An easily-grown plant, sturdy, rather straggling, but very free-flowering. In old specimens the branches become semi-pendulous. It grows best when kept in a warm house. Syn. R. grandiflora.



R. Houlletii (Houllet's); Bot. Mag. 6089.—Stems long, graceful, branching freely, round and twig-like, or with broad wings, as in Phyllocactus. Winged or flattened portions notched, and bearing a flower in each notch. Flowers stalkless, with pointed, straw-coloured petals, forming a shallow cup about 3/4 in. across the top. Stamens and pistil white, with a tinge of red at the base. Flowering-season, November. Under cultivation, this Brazilian species forms a small, straggling shrub, about 3 ft. high, but in its native woods its stems are many feet long, and pendulous from the branches of trees. It may be grown in a warm house, in a pot, and its branches supported by a stake; or its lower stems may be fastened against a piece of soft fern-stem, into which its numerous stem-roots penetrate freely. In the winter it should be kept almost dry. The flowers remain fresh for several days, and are fragrant. A well-grown plant, when in flower, is an interesting and pretty object. It is the most ornamental kind.

R. Knightii (Knight's).—Stems and joints as in R. commune. Wings of joints usually broad, with red margins, and the hair in the notches in a dense tuft, nearly 1 in. long, pure white, and silk-like. Flowers small, white. This species, which thrives best under warm-house treatment, is a native of Brazil, and is usually grown only for its curious, Cereus-like stems. It forms a straggling plant about 1 ft. high. Syn. Lepismium Knightii, Cereus Knightii.

R. mesembryanthemoides (Mesembryanthemum-like); Bot. Mag. 3O78.—A small, compact plant, with woody stems, densely covered with little fleshy, conical joints, resembling very closely the leaves of some of the Mesembryanthemums. They are green, with a few red dots, each bearing a very small tuft of the finest hair-like spines. The flowers are developed in March, from the sides of the small joints; they are 1/2 in. across, and yellowish-white. Fruit a small, white, round berry. Native of South America, whence it was introduced in 1831. When grown in a warm house, in a small, round, wire basket, filled with peat and sphagnum, this little Cactus forms a pretty tuft, which in the spring produces large numbers of white, star-like flowers.

R. myosurus (mouse-tailed); Bot. Mag. 3755.—Stems dependent, several feet long, branching freely, jointed, with three or four angles or wings; the angles flattened, reddish, notched in the margin, and bearing a tuft of white, silky hairs in each notch. Flowers small, yellow, tinged with red, springing from the notches; produced in July. Fruit not seen. A native of Brazil; introduced in 1839. This species resembles some of the angular-stemmed kinds of Cereus. It grows freely and flowers annually, if planted in a basket of fibrous soil, and suspended near the glass in a warm greenhouse or stove. It is attractive even when not in flower, owing to the form of its stems and the tufts of long, silky, white hair which spring from the notches. Syn. Lepismium myosurus.

R. pachyptera (thick-winged); Bot. Mag. 2820.—Stem woody; branches jointed, flattened as in Phyllocactus, with deep notches; width of joints, 2 in. or more. Flowers small, yellowish-white, borne singly in the notches in November. Fruit a small, white berry, rarely ripened. A sturdy, comparatively uninteresting stove plant, introduced from Brazil in 1830. Syn. Cactus alatus.