mes open very early in the morning and fade in the
afternoon, so that they may be enjoyed during the day-time. The flower
tube is 6 in. long, curved upwards, and clothed with rose-tinted scales,
which become gradually larger towards the top, where they widen out into
a whorl of greenish-yellow sepals, above which are the white petals
forming a broad shallow cup, 8 in. across, with a cluster of yellow
stamens in the centre. The stems are three-angled, light green, and bear
clusters of short stiff spines along the angles at intervals of 2 in.
Flowers in autumn. Mexico (?), 1835.

C. nycticalus (flowering at night); Fig. 15.--Stems four to six-angled,
2 in. wide, dark green, bearing little tufts of hair and thin white
spines along the angles, and a profusion of aerial roots. Flowers as
large as those of C. grandiflorus; tube covered with tufts of white
hairs; sepals or outer whorl of segments bright orange, the inner pure
white, and arranged like a cup. They open at about seven o'clock in the
evening, and fade at seven on the following morning. This plant may
still be met with in some old-fashioned gardens, but only rarely as
compared with its popularity a generation ago, when it was to be found
in almost every collection of stove plants. At that time, the flowering
of this Cactus was looked upon as an event, and it was customary for the
owner to invite his friends to meet and watch the development of the
flowers, and enjoy to the full their almost over-powering but delicious
fragrance. So bright are the colours of the flowers, that a sort of
luminosity seems to surround them when at their best. Flowers in autumn.
Mexico, 1834.

[Illustration: FIG. 15.--CEREUS NYCTICALUS.]

C. triangularis (three-angled); Bot. Mag. 1884.--This plant is easily
recognised because of its stout triangular stems, which increase at a
rapid rate and bear roots freely; by means of these roots they cling to
almost any substance with which they come in contact. There are large
examples of it in the Kew collection, where it bears numerous flowers
annually, which open in the evening and close at about eight o'clock
next morning. The flowers measure 1 ft. in length by about the same in
width of cup, and are composed of a whorl of long narrow green sepals,
with pale brown points, a cluster of pure white petals, bright yellow
stamens, and a large club-like stigma; they appear in autumn. Mexico.
This species was cultivated at Hampton Court in 1690.

C