[Illustration:  Fig. 44.—­Echinocactus scopa.]

E. scopa cristata. (crested variety); Fig. 45.—­This curious monstrosity owes its origin to fasciation similar to what occurs in the Celosias or Cockscombs, in some Echeverias, &c.  These monster varieties of Cactuses do not flower, but they are nevertheless interesting, and worth growing on account of their curious shapes.  The plant shown in Fig. 45 is grafted on the stem of a Cereus, and it is remarkable that a portion of the crest of the Echinocactus will, if grafted on to another plant, develop the abnormal form of its parent, proving that the variation, whatever its cause, has become fixed.

[Illustration:  Fig. 45.—­Echinocactus scopa cristata.]

E. Simpsoni (Simpson’s).—­One of the smallest plants in the genus, and one of the prettiest.  It produces tufts of irregularly-formed stems about 4 in. high, and composed of numerous rounded tubercles over 1/2 in. wide, bearing on the top of each a tuft of about twelve spines 1/2 in. long.  The flowers are borne from the apex of the young tubercles, and are 1 in. wide and long, cup-shaped; petals pale purple, the stamens yellow.  Native of Mexico and Colorado, where it is found at elevations of 8000 ft. to 10,000 ft., in great abundance, forming large patches on gravelly morains, where the climate during the summer is dry, whilst in winter a thick covering of snow protects the plants from severe frosts.  In England, this species is said to have withstood 32 degs. of frost without being injured.  It has been grown out of doors in a garden at Northampton, where it passed several winters planted in a raised border at the foot of a south wall with a natural coping of ivy.  In New York, where the frosts of winter are severer than in England, it is cultivated out of doors.  In this country it is apt to be injured by excessive moisture and fogs; but by protecting it with a handlight from November to March or April, this is overcome.  If grown in pots, it should be kept in a position where it can enjoy all the sunlight possible.

E. sinuatus (undulated).—­Stem about 8 in. wide and long; globose, bearing fourteen to sixteen ridges, the edges of which are wavy or undulated, the prominent points crowned with tufts of thin, flexuous, yellow spines, the longest 11/2 in., and hooked, the shorter 3/4 in., and straight.  The stem of E. longihamatus is very similar to this.  Flowers developed on the top of the stem; tube short, scaly, green; petals yellow, spreading, and forming a cup 3 in. across, which is greenish outside.  A native of Mexico, where it flowers in April.  A recently-introduced kind, not yet flowered in this country.  It is described as being a distinct, large-flowered, handsome species.

E. tenuispinus (thin-spined); Bot.  Mag. 3963.—­Stem globular, depressed, with ridges and spines similar to those of E. Ottonis; indeed, by some these two are considered forms of the same species.  In the number and size of the flowers, their colour and form, and the time of flowering, there is no difference between them.  Native of Mexico (and Brazil ?).