one central and projecting outwards; they
are pale brown when old, and white when young; their length is about
1/2 in. A tuft of short, white wool is developed at the base of the spines
on the young mammae. The stem is seldom more than 4 in. in height, and it
branches at the base when old. Flowers large and handsome,
citron-yellow; the tube short, and hidden in the mammae; the petals
11/2 in. long, narrow, pointed, and all directed upwards; stamens numerous,
short. Flowering season, early summer. Native country, Mexico. It
requires greenhouse treatment, or it may be placed in a sunny frame out
of doors during summer. It is not easily multiplied from seeds, but is
free in the production of offsets from the base of the stem.

[Illustration: FIG. 63. MAMILLARIA LONGIMAMMA.]

M. macromeris (large-flowered); Fig. 64.--Stem about 4 in. high, naked
at the base, woody and wrinkled when old. Tubercles as in M. longimamma,
but with curving radial spines, like needles, often 2 in. in length,
white or rose-tinted when young, almost black when old. Flowers from the
centre of the stem, 3 in. long, and about the same in width; the petals
regular and spreading, as in the Ox-eye daisy; stamens numerous, short,
forming a disk; colour carmine, almost purple just before fading.
Flowering season, August. Native of Mexico, where it is found in loose,
sand on hillocks, generally about the roots of Acacias. It is one of the
most beautiful of all Mamillarias; but it is, as yet, rare in
collections. It requires the same treatment as M. longimamma, except
that, owing to the woody nature of its rootstock, and its long, tap-like
roots, it should be planted in pans instead of pots, using a compost of
rough loam, mixed with lumps of broken brick or limestone.

[Illustration: FIG. 64. MAMILLARIA MACROMERIS.]

M. macrothele (large-nippled); Bot. Mag. 3634, as M. Lehmanni.--This
belongs to the same group as M. cirrhifera, but is distinguished by its
large mammae, which are four-angled at the base, 3/4 in. long, narrowed to
a point, upon which is a tuft of wool and a cluster of about eight
spines, 1/2 in. long, spreading, reddish-brown in colour, the central one
being almost black, 1 in. long, and pointing downwards. In the axils of
the mammae are tufts of white wool. Flowers on the top of the stern,
erect, spreading, about 11/2 in. across when expanded; the petals
overlapping, and pale yellow; the stamens red at the base, arranged in a
dense cluster,