[E. myriostigma.] (many-dotted); Fig. 40.—In the form of the stem of this species we have a good illustration of how widely a plant may differ from others of the same genus in certain of its characters, for the spines are almost totally suppressed, and the ridges are regular, deep, and smooth. There are usually five or six ridges, a transverse section of the stem revealing a form exactly like the common star-fish (Astrophyton), a resemblance to which the name Astrophytum, sometimes applied to this plant, owed its origin. The form of the stem is well represented in the Figure. The white dots shown on the bark, and which look like scales, are composed of very fine interwoven hairs, which, under a microscope, are very pretty objects. This species was introduced from Mexico along with the large plant of E. Visnaga described at the beginning of this chapter, and was first flowered at Kew, in July, 1845. Stems 1 ft. in length were received, along with shorter ones; but only the small ones were established. The flowers are daisy-like, 1½ in. across, and are straw-coloured, the petals being tipped with black. It thrives under warm greenhouse treatment. When without its flowers, it looks more like a piece of chiselled stone than a living plant.
FIG. 40.—ECHINOCACTUS MYRIOSTIGMA
[E. obvallatus] (fortified); Fig. 41.—The form of stem in this species is shown in the Figure. It grows very slowly plants 4 in. through taking about ten years to reach that size from seeds. The spines are stout, all deflexed, and arranged along the edges of the numerous ribs into which the stem is divided. The flowers are developed from the centre of the plant, and are surrounded by the erect spines, which crown the, as yet, undeveloped tubercles. Two or three flowers are produced at about the same time, each one being composed of a short, spiny tube, and a whorl of erect petals, which are pointed, purple-coloured, paler at the margin, the stamens being yellow. Native of Mexico. It requires a stove temperature, and flowers in summer.
FIG. 41.—ECHINOCACTUS OBVALLATUS
[E. Ottonis] (Otto's); Bot. Mag. 3107.—A dwarf kind, with a balloon-shaped stem, rarely exceeding 4 in. in height, and divided into a dozen wide ridges with sharp, regular edges, along which are clusters of small, brown spines, set in little tufts of wool, and looking like an array of spiders. The flowers are borne on the tops of the ridges, and are pale yellow in colour, with a band of red hair-like spines surrounding the calyx just below the petals, which are narrow, spreading, and look not unlike the flowers of the yellow Marguerite; the stigma is bright red. The symmetrical form of the stem, with its rows of spider-like spines, renders this plant attractive, even when without its bright and pretty flowers. It thrives only in a warm stove. Introduced from Brazil in 1831, flowering in the month of July. As it produces young plants about its base, it may be easily propagated by removing them and planting them in soil; or they may be grafted as advised for other of the small, globose-stemmed kinds.
[E. pectiniferus] (comb-bearing); Bot. Mag. 4190.—One of the most striking of the plants of this genus, owing to the character of its stem, and the large size and beauty of its flowers. The former resembles a pear with the thin end downwards; its height is from 4 in. to 6 in., and it has about twenty ridges, which are sharply defined and bear along their angles little cushions of white wool ½ in. apart, with a radiating cluster of brown spines springing from each. The arrangement of the spines in rows is not unlike the teeth of a comb. The flowers are borne near the top of the stem, and consist of a green, fleshy tube, clothed with spines and little tufts of white wool; the sepals form a row beneath the petals, and are yellowish, tinged with purple; petals 2 in. long, broad, with the upper margins toothed and the tip acute, their colour being bright rose, tinged with greenish-white at the base; stamens yellow; stigma large, green. The form of the flowers is that of a cup, nearly 3 in. across. Introduced from Mexico in 1845. Flowering season, April and May. It requires warm-house treatment.
[E. polycephalus] (many-headed); Fig. 42.—Stem globose when young, becoming cylindrical with age; number of ribs varying from twelve to twenty, sharply defined, and bearing, at intervals of 1 in., clusters of stout, reddish spines, somewhat flattened on the upper side, and marked with raised rings, or, as it is termed, annulated, the central ones attaining a length of over 3 in. on old plants, and sometimes curved. The flowers are enveloped at the base in a dense mass of white wool, which hides the tube, its spines only showing through; petals narrow, 1 in. long, spreading like a saucer, and coloured bright yellow; stamens numerous, yellow, as also is the large rayed stigma. California and Colorado, on stony and gravelly hills. Flowers in spring; introduced to Kew in 1886. This new plant is remarkable in that it is often found wild with as many as twenty to thirty stems or heads springing from the same base, and even young plants show early a disposition to develop several heads. The largest stems are from 1½ ft. to 2½ ft. high, and have a somewhat forbidding appearance, owing to the size and strength of their numerous spines. For its cultivation, a warm-house temperature appears most suitable; it bears a close resemblance to E. texensis.
