38 SOUTH AFRICAN FLOWERING PLANTS. 



and end in sharp spines, as in the Kei-apple tree, and 

 of the tree shown on Fig. 19. 



But besides this hardening effect of drought and 

 heat, many plants have adopted a plan of storing up 

 the water when the rain falls. Thus the very common 

 plants known as Mcsemlrian'themum have thick, fleshy 



Fig. 19.— Spines of Celas'trus 

 bux'fo'lius, L. 



Fio. 20. — Stapc'lia. Stem and 

 flowers. 



leaves, full of water, and protected by a thick skin ; 

 one species, called the "Ice-plant," is covered with 

 little bladder-like projections on the leaves, each of 

 which is like a miniature bottle of water without a neck. 

 Many of the Crassula family are similarly provided ; 

 while others, as the fleshy EitphorUas and Stapelias, 

 store up water in their stems (Fig. 20). Hence all 



