FIG. 47.—ECHINOCACTUS UNCINATUS
[E. viridescens] (greenish).—Stem 1 ft. high and 9 in. across, young plants being broader than high; the sides split up into about twenty ridges, which are again divided into knotty tubercles or waves. The spines are remarkable for their size and strength, those on large plants being 4 in. long by ½ in. broad at the base, gradually narrowing to a stiff point; there are four central spines of this size, the others, of which there are about a dozen, being shorter and thinner, and arranged stellately. The flowers, which are rarely produced, are poor in comparison with the majority of the flowers of this genus. As the name denotes, their colour is yellowish-green; and they are about 1½ in. wide and high. There are often as many as a dozen flowers expanded together on a stem of this plant when wild, and they are arranged in a circle around the growing point. The interest in this species, however, centres in its spines rather than its flowers. It is a native of the dry hills of California, extending sometimes down to the sea-beach. There is a plant of it at Kew 6 in. high and about fifteen years old; it has not been known to flower there. Mr. Peacock also possesses a large plant of it.
[E. Visnaga.] (visnaga means a toothpick among the Mexican settlers); Fig. 48.—Of the most remarkable features of this truly wonderful Cactus we have already spoken earlier in this Chapter. In 1846, Sir W. J. Hooker described, in the Illustrated London News, a large plant of it, which had been successfully introduced alive to Kew, and which, a year or so later, flowered, and was figured in the Botantical Magazine (4559). Its height was 9 ft., and it measured 9½ ft. in circumference; its weight a ton. Afterwards, it exhibited symptoms of internal injury. The inside became a putrid mass, and the crust, or shell, fell in by its own weight. The shape of the stem is elliptical, with numerous ridges and stout brown spines arranged in tufts along their edges. The flowers are freely produced from the woolly apex; the tube is scaly and brown, and the petals are arranged like a saucer about the cluster of orange-coloured stamens. The colour of the petals is bright yellow, and the width of the flower is nearly 3 in. This plant is a native of Mexico, and is usually cultivated in a tropical temperature, but it would probably thrive in a warm greenhouse. It flowers in summer. As we have stated, large specimens do not live long in this country; and as the flowers are only borne by such, the plant, except only for its stems, is not to be recommended for ordinary collections.
FIG. 48.—ECHINOCACTUS VISNAGA
[E. Williamsii] (Williams's); Bot. Mag. 4296.—A very distinct dwarf species, often called the "Dumpling Cactus," from the puffed-out, tumid appearance of its stems, which frequently branch at the base, so as to form a tuft of several heads; these are turbinate, 3 in. or 4 in. high, and 2 in. across the top, where the smooth, pale green flesh is divided into about half-a-dozen rounded tubercles, pressed closely together, and suggesting a number of small green potatoes joined by their bases. Each tubercle bears several tufts of short hairs. The flowers proceed from the young tubercles near the centre of the crown, their bases being enveloped in pale brown wool, the petals spreading out daisy-like to the width of 1 in., with a short disk of stamens in the middle; they are white, tinged with rose, and are developed in the summer months. Native of the rocky hills of Mexico, whence it was introduced in 1845. The stems of this plant are its most distinctive feature. It thrives on a shelf in a warm greenhouse, if kept perfectly dry in winter, and it should be potted in a compost consisting of broken brick two-thirds, loam one-third.
[E. Wislizeni] (Wislizen's); Fig. 49.—A large-stemmed kind, second only in size to E. Visnaga. Young plants have depressed stems, those in older specimens being cylinder-shaped. A specimen at Kew is 8 in. high by 18 in. in diameter, with twenty-one ridges, which are regular and sharp-edged, and bear bunches of spines at regular intervals, the outer and shorter ones being spreading and white, whilst from the middle of each tuft arise four longer and stouter spines, three of them 2 in. long, and one 3 in., with the point hooked, and as strong as if made of steel. The flowers, which are developed only on large plants, are greenish-yellow, about 2 in. long and wide, and expand during summer and autumn. The juice of the stems is said to serve as a substitute for water when the latter is scarce, and instances have been known among the white trappers where the lives of men have been saved by this plant. A novel use the stems are put to by the Indians is that of boilers, a purpose which they are said to answer well. The fleshy inside is scooped out, and the tough skin, with its iron-like spine protection, is then filled with vegetables and water and placed on the fire. As there is a plentiful supply of plants, the Indians do not trouble to carry this "boiler" about with them, but make a fresh one at every stage of their journeyings.
FIG. 49.—SPINES AND FLOWERS OF ECHINOCACTUS WISLIZENII