and flattened at the base.  The flowers are 4 in. broad and long, the tube short, green, and bearing reddish scales, which gradually pass into bright yellow petals blotched with red on the outside, the inner ones spreading and forming a shallow cup, in the centre of which are the short yellow stamens and large pistil.  Plants of this species have been grown with stems 20 in. high; but it takes a great number of years for the development of such specimens.  The flowers are produced on the apex of the stem in July.  This species was introduced from Mexico about 1850; it thrives only when grown in a warm greenhouse, where the temperature in summer may be allowed to run up to 90 degs. with sun heat.  For large collections it is one of the most desirable.

[Illustration:  Fig. 39.—­Portion of plant of Echinocactus longihamatus.]

E. Mackieanus (Mackie’s); Bot.  Mag. 3561.—­A small plant, not more than about 5 in. high, and 2 in. broad at the base, widening slightly upwards.  The ridges are broken up into numerous fleshy, rounded, green tubercles, crowned with a tuft of thin brown spines from 1/2 in. to 1 in. long, their bases set in a small pad of yellow wool:  As the stem gets older, it loses its tubercles at the base, which are changed into brown wrinkles.  The flowers are developed on the top of the stem, generally two or three together, egg-shaped and scaly when in bud, 21/2 in. across when expanded; the petals white, tipped with brown; the stigma green, club-shaped.  This curious little Cactus is one of about a dozen species found in the Chilian Andes.  It was introduced in 1837 by the gentleman whose name it bears, and who, at that time, possessed a famous collection of Cacti.  Like the rest of the Chilian kinds, it should be cultivated in a cool greenhouse in full sunshine, where it will produce its flowers in summer.

E. mamillarioides (Mamillaria-like); Bot.  Mag. 3558.—­This is another small, tubercled species, which, like the preceding, is a native of Chili.  Its stem is very irregular in form, owing to the crowding of the tubercles, which look as if they were filled with water.  The spines are small, in tufts of about half a dozen, set in a little cushion of yellowish wool.  In size, the whole plant is like E. Mackieanus, but it blossoms more freely, as many as sixteen flowers having been borne at one time by a plant at Kew.  These were short-tubed, the calyx clothed with green scales, and the petals 2 in. long, recurved at the apex, forming a beautiful cup-like flower of a bright yellow colour, with a band of red down the centre of each petal; the stamens and pistil yellow.  The number of flowers developed on the small stem formed by this plant is quite extraordinary.  It grows and flowers freely in an ordinary greenhouse, and would thrive in a sunny window if kept dry during the winter.