snow without suffering; but it would not thrive out of doors in winter
with us, unless covered by a handlight during severe weather, and
protected from heavy rains in winter. It likes a strong, clayey soil.

M. v. radiosa (Fig. 73).--This variety is distinguished by its larger
flowers and shorter spines.

[Illustration: FIG. 73. MAMILLARIA VIVIPARA RADIOSA.]

M. Wildiana (Wild's).--An old garden Cactus, and one of the prettiest
of the tufted, small-stemmed kinds. Its largest stems are 3 in. high by
about 11/2 in. in diameter, and bear spiral rows of clavate, dark green,
crystallised tubercles, 1/2 in. long, with about ten radial white spines,
1/2 in. long, the three upper spines, together with the solitary central
hooked one, being yellow. Flowers small, numerous on the apices of the
stems, rose-coloured, lined with purple; they are developed in summer.
This also forms dense tufts of stems. A specimen at Kew, only a few
years old, has already over thirty heads. It is a native of Mexico, at
an altitude of 5000 ft., growing on lava and basalt, and even on the
trunks of trees. For its cultivation, a shelf in a sunny greenhouse is a
most suitable position, both in winter and summer. Introduced 1835.

M. Wrightii (Wright's).--This is a charming little plant, of something
the same character as M. dolichocentra. It has not long been cultivated
in gardens, but being easy to manage, and exceptionally pretty, it is
sure to become a favourite as it gets known. Stem rounded above,
narrowed and peg-top-like at the base, the top flattened, about 3 in.
across, height about the same. Tubercles conical, 1/2 in. long, shining
green, and bearing a tuft of six or eight spines, which are straight,
hair-like, white, and 1/2 in. long; there are two central spines, of same
length, and hooked. Flowers in the top of the stem, 1 in. long and wide,
bright purple; they are succeeded by egg-shaped, purple berries, 1 in.
long, and prettily arranged among the tubercles. In England a warm house
seems most suitable for this species. It likes plenty of moisture and
sunlight during the summer, whilst making new growth; but in winter,
when at rest, it ought to be kept on a shelf, and just moistened
overhead in bright weather. There are healthy examples of it at Kew.
Flowering season, May and June. Native country, Mexico. Introduced about
1878.

M. Zucchariniana (Zuccharini's).--Stem simple, globose, often attaining
a height of 10 in. by about 7 in. i