ably from Mexico. It
may be grafted on to another free-growing kind with advantage, as it
does not always keep healthy when on its own roots. It should be grown
in a cool greenhouse, or in the window of a dwelling-room, always,
however, in a position where it would get plenty of sunlight.

E. Haynii (Hayne's); Fig. 35.--An upright cylindrical-stemmed species,
very much like a Mamillaria in the form and position of the tubercles
and the numerous greyish hair-like spines arranged in a radiating ring
on the top of each tubercle. The flowers are much longer than in any yet
described, the tube being 6 in. in length, clothed with large sepals on
the upper portion, and the petals are semi-erect with recurved points,
and coloured a brilliant purple-red. A native of Peru, where it is found
at high elevations, growing in crevices of rocks and exposed to full
sunlight. With us it thrives in a warm greenhouse, producing its
beautiful flowers in summer. Introduced about 1850.

[Illustration: FIG. 35.--ECHINOCACTUS HAYNII.]

E. hexaedrophorus (tubercles six-sided); Fig. 36.--This plant is
distinguished by the gouty-looking tubercles into which its broad,
spiral ridges are divided, and which look as if they would suddenly
burst like a blister if pricked with a pin. It grows about 4 in. in
height, and is similar in form to what is shown in the accompanying
figure, except that the top is usually flatter than here represented.
The whole stem has a glaucous hue, and the spines are reddish-brown. The
flowers, which are produced freely in June and July, are short-tubed,
spreading to a width of 2 in.; the petals toothed at the tips, and
arranged in several rows, overlapping each other, the colour being
white, tinted with rose, with a disk-like cluster of yellow stamens in
the centre, and a white-rayed stigma. A native of North Mexico,
introduced about 1830. It is very slow-growing, attaining full size in
not less than six years from seed; indeed, it is stated that in twelve
years a plant of it did not grow more than 2 in. Still, slow as it is, it
remains in good health when kept in a sunny position on a shelf in a
greenhouse or in a dwelling-room, so that it may be recommended for
places where space is very limited. Like E. gibbosus, it does best when
grafted on to another kind. We have seen perfect "drum-sticks" formed by
grafting a full-grown plant of this on the stem of a Cereus.

[Illustration: FIG. 36.--ECHINOCACTUS HEXAEDROPHORUS.]