veral distinct seedling
or hybrid forms of this species, remarkable in having the colour of
their flowers either red, yellow and white, or white, whilst some, such
as the one known as flammea, have flowers only 2 in. long. These kinds
may all be grown in a sunny greenhouse or window, as they only require
protection from frost. They may be placed out of doors in summer, and be
kept under glass only during winter, treatment which will result in
better growth and more flowers than if the plants were kept permanently
under glass.

[Illustration: FIG. 52.--ECHINOPSIS PENTLANDI.]

E. P. longispinus (long-spined); Fig. 53.--This is a long-spined form,
and differs also in the shape of the stem, which is oblong, rather than
globose.

[Illustration: FIG. 53.--ECHINOPSIS PENTLANDI LONGISPINUS.]

E. tubiflorus (tube-flowered).--This species has an orange-shaped stem,
about 4 in. high, and divided into about twelve prominent, sharp-angled
ridges, along which are tufts of blackish spines, 1/2 in. long, and set in
little cushions of white wool. The flower springs from the side of the
stems, where it replaces a tuft of spines, and, as in E. Eyriesii, the
tube is remarkably long, whilst the size of the whole flower much
exceeds that of the rest of the plant, the length of the tube being
about 6 in., and the width of the flower over 4 in. The petals are pure
white, recurved, displaying the crown of yellow stamens, arranged in a
ring about the rather small, rayed stigma. The tube is uniformly green,
except that the scale-like bracts are edged with long, blackish, silky
hairs. A native of Mexico; introduced about fifty years ago, when it was
figured in the Botanical Magazine and elsewhere as a species of
Echinocactus. E. tubiflorus may be placed along with E. Eyriesii and E.
oxygonus, as it requires similar treatment. The three kinds here
mentioned may be recommended as a trio of very fine-flowered,
small-stemmed Cacti, which may be grown successfully in any ordinary
greenhouse.

CHAPTER IX.

THE GENUS MELOCACTUS.

(From melon, a melon, and Kaktos, a name applied by Theophrastus to a
spiny plant; the species are melon-formed, and their angles are beset
with tufts of spines.)

This genus forms a group of well-marked and curious plants, with stems
similar to those of the globose Echinocactuses and floral characters
quite distinct from all other genera. They cannot be said to possess any
particular beauty, as their stems ar