CACTUSES AND OTHER SUCCULENTS 



113 



others for other succulents ; while not a few have struck out a 

 distinct line for themselves. Most of the species have 

 beautiful flowers, and require greenhouse treatment. 



Opuntia (Prickly Pear). — A genus of cactuses with 



S. californicuin. 



S. aracluioideiun. 

 Fig. 49. — Sempervivums. 



branched and jointed stems, some prostrate and others more 

 or less erect. Two or three of them, such as O. missouriensis 

 and O. Rafinesqidi^ are natives of North America, and in the 

 South of England are sometimes grown in the open air 

 throughout the year ; but they require a warm and sheltered 

 corner, and their hardiness depends on their being kept dry in 



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