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 ½ in.
thick; they are slightly tuberculated, and bear tufts of spines nearly
1 in. long. Flowers 1½ 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 1½ 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 1½ 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, ¾ 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 2½ 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.
[Illustration: FIG. 76. OPUNTIA BASILARIS.]
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 1½ 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.
[Illustration: FIG. 77. OPUNTIA BOLIVIANA.]
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.
[Illustration: FIG. 78. OPUNTIA BRACHYARTHRA.]
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 1½ 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 ¼ in.
apart, composed of numerous spines, varying from short and bristle-like
to 1 in. in length, stout, flattened, and spear-like. Leaves ¼ in. long.
Flowers yellow, 1½ in. across. Fruit 1½ 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, 1½ 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 1½ 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 1½ ft. in height; joints 4 in. to 6 in. in length, and about ½
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 1½ 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 ¼ 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.
[Illustration: FIG. 79. OPUNTIA DILLENII.]
O. echinocarpa (spiny-fruited).--A low, straggling shrub, not exceeding
1½ 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
½ 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 1½ ft.
high. Joints cylindrical, curved, 4 in. long, 1½ 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
2½ in. in diameter, sulphur-yellow, tinged with purple, produced in
August and September. Fruit 2½ 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 1½ 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 1½ 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.
[Illustration: FIG. 80. FRUITING BRANCH OF OPUNTIA FICUS-INDICA.]
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 ½ 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
2½ 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.
[Illustration: FIG. 81. OPUNTIA FILIPENDULA.]
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 ¼ 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, ½ 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 1½ in. long and ¾ 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 ½ in. apart, rather large, with numerous spines,
varying in length from ½ 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, ½ 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.
[Illustration: FIG. 82. FLOWERING BRANCHES OF OPUNTIA MACRORHIZA.]
[Illustration: FIG. 83. ROOTS OF OPUNTIA MACRORHIZA.]
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, 1½ in. long, springing from the centre of
each cushion, and pointing downwards. Flowers sulphur-yellow, 2½ 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 1½ 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 ½ in. to l½ 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 ¼ in. to 1½ 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 1½ 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, 1½ 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.
[Illustration: FIG. 84. OPUNTIA RAFINESQUII.]
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 ½ 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.
[Illustration: FIG. 85. OPUNTIA ROSEA.]
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, ½ 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 ½ 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 ½ 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.
[Illustration: FIG. 86. OPUNTIA TUNA.]
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 ¾ in. apart; tufts very
small, with, occasionally, a long spine. Leaves fleshy, very small.
Flowers 2 in. across, pale sulphur-yellow. Fruits nearly smooth, 1½ 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.