1 in. to 4 in.  The flowers are 3 in. long, the tube clothed with heart-shaped scales or sepals; the petals are red, with yellowish margins, spreading so as to form a beautiful, large, cup-like flower, with a cluster of deep yellow stamens in the centre.  The flowering period is in the autumn, and the plant is a native of the Lower Colorado and California.  Living plants of it have only recently been introduced into English collections.  At Kew, it is cultivated in a warm greenhouse, where it is in good health.  From accounts of it in its native haunts, it will, however, probably prefer a cool house in winter, and as much sun and warmth as possible in spring and summer; for we are told that during winter it is often subjected to severe frosts and heavy snowfalls, whilst in summer the fierce heat of the sun is such as to burn up all vegetation, except Cactuses and other similar plants.

[Illustration:  Fig. 34.—­Flower and spines of Echinocactus emoryi.]

E. gibbosus (humped).—­A small apple-like plant, not more than 4 in. high, with a depressed top, the lower part being narrowed.  It has sixteen ribs or ridges, composed of rows of thick fleshy tubercles, upon every other of which are six or eight horny spines, 1 in. long.  The flowers are pushed out from the edge of the depression on the top of the stem, and are large; the tube 11/2 in. long.  The petals spread to a width of 3 in., and are arranged in several rows, overlapping each other, becoming smaller towards the centre of the flower, as in an aster; they are pure white, except for a tinge of red on the tips of the outer ones, the stamens being bright yellow.  Two flowers are usually developed on a plant, generally in June.  This species was introduced from Jamaica about 1808, by a nurseryman in Hammersmith; but as no Echinocactuses are wild in the West Indian Islands, it must have been introduced into Jamaica from some of the Central American States, or probably from Mexico.  It may be grafted on to another free-growing kind with advantage, as it does not always keep healthy when on its own roots.  It should be grown in a cool greenhouse, or in the window of a dwelling-room, always, however, in a position where it would get plenty of sunlight.

E. Haynii (Hayne’s); Fig. 35.—­An upright cylindrical-stemmed species, very much like a Mamillaria in the form and position of the tubercles and the numerous greyish hair-like spines arranged in a radiating ring on the top of each tubercle.  The flowers are much longer than in any yet described, the tube being 6 in. in length, clothed with large sepals on the upper portion, and the petals are semi-erect with recurved points, and coloured a brilliant purple-red.  A native of Peru, where it is found at high elevations, growing in crevices of rocks and exposed to full sunlight.  With us it thrives in a warm greenhouse, producing its beautiful flowers in summer.  Introduced about 1850.