1704 



A TEXTBOOK OF THEORETICAL BOTANY 



Though seldom seen because of their short duration, the flowers of many 

 Cacti are surprisingly large and extremely beautiful (Fig. 1570). The 



Fig. 1570. — Echinopsis tiibiflora. Flower in 

 face view. (See also Fig. iiii.) 



Fig. 1 57 1. — Epiphyllimt (Phyllocactus) 

 ackermanmi. 



great pink or red blossom of Epi- 

 p/iyllum (Phyllocactus) (Fig. 1571) 

 which is so often cultivated in green- 

 houses is a case in point, while many 

 of the tiny species produce flowers as 

 large as the plant. 



The Cactaceae are an American 

 family, the only exceptions being the 

 African species of R/iipsalis. The 

 Prickly Pears [Opiintia) are however 

 extensively naturalized in many 

 places, notably round the Mediter- 

 ranean. Some of the Cacti are quite 

 hardy and range as far as the north 

 of British Columbia. 



Nearly all Cacti are spiny, the 

 spines possibly representing the 

 leaves, which are not developed 

 except in Pereskia, which has woody 

 stems and succulent leaves. 



