ECHINOCACTUS. 51 



Several flowers are sometimes developed together in summer. 

 Mexico, 1840. Requires a warm greenhouse all the year round, and 

 plenty of sunshine. It does well when grafted on a short stem of 

 Cereus Napoleonis. (Fig. 21.) 



E. cornigerus. 



This extremely remarkable plant has the stoutest spines 

 of all Cacti. The broad tongue-like central spine in each cluster 

 is as strong as iron ; as also are the three erect horn -like yellow 

 spines. The stem is ball-shaped, grey-green, divided into from 

 fourteen to twenty-one stout wavy ribs, upon which the spine tufts 

 occur at intervals of about 2 inches. The flowers are small, with 

 narrow purple petals and brown-red sepals. Requires stove treat- 

 ment. Mexico and Guatemala. It has been called Melocactus 

 latixpinus and Echinocactus latispinus. 



E. corynodes. 



Stem about the size of an average Ribston Pippin Apple, 

 with about a dozen and a half [prominent sharp ridges, and 

 bunches of stout yellow spines. Flowers, in a cluster on the top of 

 the stem, forming a crown of bright yellow petals, studded with 

 scarlet eye-like stigmas. Each flower is 2 inches in diameter. Mexico, 

 1837. Also known as E. rosaceus and E. Sellowianus. The whole 

 plant, though small, is, when in flower, most charming. 



E. Cummiiigii. 



Stem globose, 3 inches in diameter, the spiral ridges divided 

 into tubercles, each bearing a cluster of yellow hair-like spines. 

 Flowers numerous, 1 inch long and wide, bright marigold yellow, 

 as many as half a dozen opening together in bright sunlight in 

 .July. One of the hardiest, thriving in a frost-proof house or frame. 

 In summer it likes plenty of moisture and sunshine. Bolivia. 



E. durangensis. 



Stem ovate- cylindrical, 3 inches to 10 inches high, with 

 about twenty ribs, bearing tufts of yellowish and brown stout 

 spines from 1 to 2 inches long, the lowest ones the stoutest and 

 hooked, the central angled. Flowers, brownish-red. May be only 

 a form of E. cylindraceus. Mexico. 



E. Echidne. 



Stem 12 inches by 8 inches, with about a dozen ridges, disposed 

 spirally, and bearing tufts of rigid, broad spines, 1 inch or 

 more long, spreading, so as to interlace and form a close network 

 all round the stem. It may be mentioned here that an American 

 naturalist has suggested that the purpose of spines on the stems of 

 Cactuses is not so much to defend the plants from animals so as 

 to afford protection from the scorching rays of the sun, which 

 would otherwise cause them to blister and shrivel. The nature of 



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