-yellow,
about 2 in. long and wide, and expand during summer and autumn. The juice
of the stems is said to serve as a substitute for water when the latter
is scarce, and instances have been known among the white trappers where
the lives of men have been saved by this plant. A novel use the stems
are put to by the Indians is that of boilers, a purpose which they are
said to answer well. The fleshy inside is scooped out, and the tough
skin, with its iron-like spine protection, is then filled with
vegetables and water and placed on the fire. As there is a plentiful
supply of plants, the Indians do not trouble to carry this "boiler"
about with them, but make a fresh one at every stage of their
journeyings.

[Illustration: FIG. 49.--SPINES AND FLOWERS OF ECHINOCACTUS
WISLIZENII.]

CHAPTER VIII.

THE GENUS ECHINOPSIS.

(From echinos, a hedgehog, and opsis, like.)

No less than three sections of Cactuses, viz., the above, Echinocactus,
and Echinocereus, owe their names to their hedgehog-like stems. From a
horticultural point of view, there is perhaps no good reason for keeping
the above three genera and Cereus separate; but we follow Kew in the
arrangement adopted here. The genus Echinopsis, as now recognised by
most English botanists and cultivators, comprises about thirty species,
most of which have been, or are still, in cultivation. They are
distinguished from Echinocactuses by the length of their flower tube,
from Cereuses by the form and size of their stems, and from both in the
position on the stem occupied by the flowers. They are remarkable for
the great size, length of tube, and beauty of their flowers, which,
borne upon generally small and dumpy stems, appear very much larger and
handsomer than would be expected.

The distribution of Echinopsis is similar to that of Echinocactus,
species being found in Chili, Bolivia, Peru, Brazil, Mexico, &c. They
grow only in situations where the soil is sandy or gravelly, or on the
sides of hills in the crevices of rocks.

Cultivation.--The growing and resting seasons for Echinopsis are the
same as for Echinocactus, and we may therefore refer to what is said
under that genus for general hints with regard to the cultivation of
Echinopsis in this country. The following is from the notes of the late
Curator of the Royal Gardens, Kew (Mr. J. Smith), as being worthy the
attention of Cactus growers. Writing about Echinopsis cristata, which he
grew and flowered excepti