Chapter VIII. 

 ECHINOCACTUS. 



MANY of the plants included in the genus Echinocactus are 

 very similar to species of Cereus, there being nothing by which 

 to distinguish them from each other when not in flower. 



Echinocactus was first used for E. tenuispimis when it was 

 introduced into English gardens in 1825. It is not nearly so 

 hedgehog-like as imriy that have been discovered since. Some of 

 them have stout . pine 7 ; 4 inches long, and hooked, whilst in others 

 the spines are long and needle-like, or short and fine as the prickles 

 on a thistle. The stems vary in size and form, being globose, or 

 compressed, or ovate, a few only being cylindrical, attaining a 

 height of from 5 to 10 feet. They are un branched ; the ridges vary 

 in number frcm about five to fifty, in some firm and prominent, 

 in others reduce I to mere undulations, whilst in a few they are 

 separated into numerous little tubercles or mamma?. They nearly 

 all have spines clustered along the ridges. (Generally the flowers are 

 developed from near the centre of the top of the stem, never on the 

 side as in Cereus ; they are about as long as wide, and the ovary is 

 covered with scales or modified sepals. The fruit when ripe is 

 covered with the persistent calyx scales.- The flowers open only 

 under the influence of bright sunlight, closing soon after it leaves 

 them. 



About 200 species have been described from Texas, California, 

 Peru, Brazil, Chili, and particularly Mexico, whence most of the 

 garden kinds have been introduced. The conditions under which 

 they grow naturally vary in regard to temperature and soil ; but 

 they are found in greatest numbers and in most robust health where 

 the soil is loose or sandy, and even where there is no soil at all, the 

 roots finding nourishment in the clefts or crevices of the rocks. As 

 a rule the temperature is high during summer, and falls considerably 

 in winter, some growing even where frost and snow occur ; the 

 majority of them require stove treatment. 



Few of the species of Echinocactus known to botanists are 

 represented in garden collections, though not one would be con- 

 sidered unworthy. Their flowers are large and bright coloured ; 

 and there is charm in the curious, grotesque, and often beautifully 

 symmetrical shape of their stems. E. Visnaga (Fig. 20) may be 

 taken as an example of this. This is indeed one of the most 



