SUCCULENT PLANTS 
149 
A few cactuses, belonging mostly to the genus Opuntia, may be 
grown out-of-doors. They are outlying species from the vast cactus 
region of the south-western United States, occupying 
Cactuses P os iti° ns a t a higher altitude than the great bulk of the 
family, or coming from more northerly localities. At 
Kew they are cultivated in the recesses on the south side of the Palm 
House. These hardy cactuses present no special difficulty in culti- 
vation if a suitable position can be found for them. They should 
be planted in soil with which plenty of rubble has been mixed, the 
chief thing being to secure ample drainage at the root. And they 
should, of course, have the fullest exposure to sunlight. 
