of the group with angular
tubercles and comparatively small flowers. It has a stem about 6 in.
high, cylindrical, the tubercles arranged spirally, their bases
compressed, four or five-angled, and with a tuft of white wool in their
axils. The areoles or tufts on the tops of the mammae are large, and the
spines are about seven in number, 1/2 in. long, and of a tawny-yellow
colour. The flowers are produced near the top of the stem; they are
about 1/2 in. long, and rose-red in colour. Native country, Mexico. It
requires the same treatment as M. cirrhifera.

M. Ottonis (Ottoni's); Fig. 66.--A very distinct and pretty plant is
cultivated under the name at Kew; but there are, apparently, two
different species under the same name--the one being spiny and large in
the stem; the other, which is here shown, having a small, compressed
stem, 3 in. across, numerous compressed tubercles, and short, hair-like
spines. The flowers, which are large for the size of the plant, are
white, and are developed in May and June. Native country, Mexico;
introduced in 1834. It requires similar treatment to M. micromeris.

[Illustration: FIG. 66. MAMILLARIA OTTONIS.]

M. pectinata (comb-like); Fig. 67.--Stems globose, from 2 in. to 3 in. in
diameter; the rootstock woody; the tubercles arranged in about thirteen
spiral rows, swollen at the base, and bearing each a star-like tuft of
about twenty-four stiff, brown, radial spines, without a central one;
the length varies from 1/2 in. to 1 in., and they are comb-like in their
regular arrangement. When not in flower, this species bears a close
resemblance to small plants of Cereus pectinatus. Flowers terminal,
solitary, large, their width quite 3 in. when fully expanded; sepals
reddish-green; petals rich sulphur-yellow; filaments reddish, very
numerous; the flowers open at noon, and close after about two hours,
even although the sun be shining full upon them. Flowering season, June
to August. Native country, Mexico, on slopes of limestone hills.
Although long since known to botanists, this pretty species has only
lately found its way into English gardens. It is attractive even when
not in flower. It requires warm greenhouse treatment, with exposure to
full sunshine; during late autumn it should have plenty of air to ripen
the new growth made whilst flowering. In winter it should have a dry
position near the glass.

[Illustration: FIG. 67. MAMILLARIA PECTINATA.]

M. phellosperma (corky-seeded).--A pret