Cactus Culture For Amateurs | Page 3

the smaller kinds of
Cactus. Again, in the Cactuses themselves we have curious cases of
plant mimicry; as, for instance, the Rhipsalis, which looks like a bunch
of Mistletoe, and the Pereskia, the leaves and habit of which are more
like what belong to, say, the Gooseberry family than to a form of
Cactus. From this it will be seen that although these plants are almost
all succulent, and curiously formed, they are by no means singular in
this respect.
The characters of the order are thus defined by botanists: Cactuses are
either herbs, shrubs, or trees, with soft flesh and copious watery juice.
Root woody, branching, with soft bark. Stem branching or simple,
round, angular, channelled, winged, flattened, or cylindrical; sometimes
clothed with numerous tufts of spines which vary in texture, size, and
form very considerably; or, when spineless, the stems bear numerous
dot-like scars, termed areoles. Leaves very minute, or entirely absent,
falling off very early, except in the Pereskia and several of the Opuntias,
in which they are large, fleshy, and persistent. Flowers solitary, except
in the Pereskia, and borne on the top or side of the stem; they are
composed of numerous parts or segments; the sepals and petals are not
easily distinguished from each other; the calyx tube is joined to, or

combined, with the ovary, and is often covered with scale-like sepals
and hairs or spines; the calyx is sometimes partly united so as to form a
tube, and the petals are spread in regular whorls, except in the
Epiphyllum. Stamens many, springing from the side of the tube or
throat of the calyx, sometimes joined to the petals, generally equal in
length; anthers small and oblong. Ovary smooth, or covered with scales
and spines, or woolly, one-celled; style simple, filiform or cylindrical,
with a stigma of two or more spreading rays, upon which are small
papillae. Fruit pulpy, smooth, scaly, or spiny, the pulp soft and juicy,
sweet or acid, and full of numerous small, usually black, seeds.
Tribe I.--Calyx tube produced beyond the Ovary. Stem covered with
Tubercles, or Ribs, bearing Spines.
1. MELOCACTUS. Stem globose; flowers in a dense cap-like head,
composed of layers of bristly wool and slender spines, amongst which
the small flowers are developed. The cap is persistent, and increases
annually with the stem.
2. MAMILLARIA. Stems short, usually globose, and covered with
tubercles or mammae, rarely ridged, the apex bearing spiny cushions;
flowers mostly in rings round the stem.
3. PELECYPHORA. Stem small, club-shaped; tubercles in spiral rows,
and flattened on the top, where are two rows of short scale-like spines.
4. LEUCHTENBERGIA. Stem naked at the base; tubercles on the
upper part large, fleshy, elongated, three-angled, bearing at the apex a
tuft of long, thin, gristle-like spines.
5. ECHINOCACTUS. Stem short, ridged, spiny; calyx tube of the
flower large, bell-shaped; ovary and fruit scaly.
6. DISCOCACTUS. Stem short; calyx tube thin, the throat filled by the
stamens; ovary and fruit smooth.
7. CEREUS. Stem often long and erect, sometimes scandent, branching,
ridged or angular; flowers from the sides of the stem; calyx tube
elongated and regular; stamens free.
8. PHYLLOCACTUS. Stem flattened, jointed, and notched; flowers
from the sides, large, having long, thin tubes and a regular arrangement
of the petals.
9. EPIPHYLLUM. Stem flattened, jointed; joints short; flowers from
the apices of the joints; calyx tube short; petals irregular, almost
bilabiate.

Tribe II.--Calyx-tube not produced beyond the Ovary. Stem branching,
jointed.
10. RHIPSALIS. Stem thin and rounded, angular, or flattened, bearing
tufts of hair when young; flowers small; petals spreading; ovary smooth;
fruit a small pea-like berry.
11. OPUNTIA. Stem jointed, joints broad and fleshy, or rounded;
spines barbed; flowers large; fruit spinous, large, pear-like.
12. PERESKIA. Stem woody, spiny, branching freely; leaves fleshy,
large, persistent; flowers medium in size, in panicles on the ends of the
branches.
The above is a key to the genera on the plan of the most recent
botanical arrangement, but for horticultural purposes it is necessary that
the two genera Echinopsis and Pilocereus should be kept up. They
come next to Cereus, and are distinguished as follows:
ECHINOPSIS. Stem as in Echinocactus, but the flowers are produced
low down from the side of the stem, and the flower tube is long and
curved.
PILOCEREUS. Stem tall, columnar, bearing long silky hairs as well as
spines; flowers in a head on the top of the stem, rarely produced.
With the aid of this key anyone ought to be able to make out to what
genus a particular Cactus belongs, and by referring to the descriptions
of the species, he may succeed in making out what the plant is.
For the classification of Cactuses, botanists rely mainly on their floral
organs and fruit. We may, therefore, take a plant of Phyllocactus, with
which