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.
[Illustration: FIG. 89. RHIPSALIS FUNALIS.]
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 ¾ 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 ½ 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.
R. paradoxa (paradoxical).--Stems trailing, with numerous long branches
of most extraordinary form. Imagine a three-angled, fleshy branch, often
several feet in length, the angles winged, about ½ in. deep, green, with
smooth, reddish margins. At intervals of about 2 in. the branch has the
appearance of having been twisted half round. There is no other plant
with branches anything like these. Flowers produced in November, in the
apex of the interrupted angles, small, white. Fruit seldom ripened. A
native of Brazil, whence it was introduced in 1837. There is a fine
example of this trained along a rafter in the Succulent-house at Kew.
The numerous branches hang down several feet from the rafter, and have a
most extraordinary appearance. This species requires stove treatment.
R. penduliflora (pendulous-flowered).--A small, thin-stemmed plant,
with smooth, green branches, no thicker than whipcord, and numerous
fascicled or clustered, small joints, ½ in. long, green, with red dots,
angular when young. Flowers on the tips of the terminal joints, pale
yellow, ½ in. across, developing in August. Fruit white, Mistletoe-like.
This species was introduced from tropical America in 1877, and requires
stove treatment.
R. p. laxa (loose).--This variety has the branches curving, and more
pendulous; in other respects it resembles the type, and requires the
same treatment.
R. pentaptera (five-winged).--Stems erect; branches stiff,
long-jointed, with five wing-like angles, slightly spiral, the angles
notched at intervals of 1 in. Flowers in the notches, ½ in. across, white,
produced in August. Fruit a white, Mistletoe-like berry. A curious plant
from Brazil, and introduced in 1836. In stove temperature it forms a
compact pot-shrub, 2 ft. high, and is worth growing on account of its
singular stems.
R. rhombea (diamond-branched).--Stems and branches as in R. crispata,
but without the wavy margins, and with more elongated joints. Flowers
small, white, produced in the notches of the joints in November. Fruit a
shining, milk-white berry. A compact plant from Brazil, worth growing
for its bright green, leaf-like stems. It should be grown in pots, in
stove temperature, and encouraged to form a globose bush.
R. Saglionis (Saglio's); Bot. Mag. 4039.--A tiny plant, similar in
habit to R. penduliflora, but with brown branches, the small joints
angled, and bearing silky hairs. The branches and joints are set at
zigzag angles. Flowers pale yellow, produced in autumn on the younger
joints. Fruits white, Mistletoe-like. A small, delicate plant from
Buenos Ayres, not more than 6 in. high. This species requires stove
treatment.
R. salicornoides (Glasswort-like); Bot. Mag. 2461.--Stem woody when
old, brown, jointed like hens' toes, not quite as thick as a
goose-quill. Branches in clusters; joints ½ in. to 1 in. long, the lower
half much thinner than the upper, so that the joints look like a number
of superposed, miniature clubs. Flowers pretty, on the ends of the
terminal joints, yellow, becoming red with age. An erect plant, 3 ft. or
more high, introduced from Brazil in 1830. The joints are clustered on
the upper part of the stem. When in flower in spring this is an
attractive and very remarkable-looking plant. It thrives best in stove
temperature.
R. s. stricta (straight).--This variety has the joints all pointing
upwards, and is much more compact than the type.
R. sarmentacea (runner-stemmed); Fig. 90.--A creeping, prostrate plant,
with round stems as thick as a goose-quill, and attaching themselves to
tree-trunks or other bodies by means of numerous adventitious roots,
which spring from the under side of the stems. Surface of stem furrowed,
and covered with numerous small clusters of short, hair-like, whitish
spines. Flowers 1 in. across, springing from the sides of the stems, with
pointed, creamy-white petals; stamens spreading; stigma erect,
four-lobed. Fruit small, currant-like. This is a pretty little species,
introduced from Brazil in 1858; it is, however, a very slow grower,
plants ten years old being only a few inches in diameter. It should be
grown in stove temperature, in a basket of peat fibre, or, better still,
on a piece of soft fern-stem. It is always found on the branches or
trunks of trees when growing wild.
[Illustration: FIG. 90. RHIPSALIS SARMENTACEA.]
R. Swartziana (Swartz's).--Older stems three-angled, young ones
flattened, jointed; joints 2 in. broad, stiff with deep notches. Flowers
in the notches, small, white, produced in June. This species is a native
of Jamaica, and was introduced in 1810. A stiff, ungraceful plant, about
2 ft. high, very similar in its branches to a Phyllocactus. This species
requires the temperature of a stove.
R. trigona (triangular).--Habit straggling; branches usually in forks,
¼ in. in diameter, three-angled; angles wavy or slightly notched,
grey-green. Flowers small, produced in spring in the notches of the
angles, white. Fruit a white berry. A thin, Brazilian plant, not unlike
a Lepismium, but without the silky hairs in the notches of the angles.
This species also requires to be grown in stove temperature.