1718 



A TEXTBOOK OF THEORETICAL BOTANY 



or purple in colour and open only in the brightest sunshine. They are 

 natives of Peru, California, Chile and Australia. Claytonia perfoUata (Fig. 

 1592) (Winter Purslane), a native of North America, is now naturalized in 

 parts of Britain. It is botanically interesting because of its perfoliate leaves. 



Fig. 1592. — Claytonia perfoliata. Flowers. 



F"inally the genus Lezvisia contains a number of species which are 

 cultivated as rock-garden plants. They are natives of North-eastern America 

 and are calcifuge plants, needing a sandy soil and protection from excessive 

 rain. 



The Aizoaceae, or as they are sometimes called the Ficoidaceae, are 

 mostly low-growing succulent herbs, found mainly in South Africa and the 

 Mediterranean, while a few are native to South America, the West Indies 

 and Australia. They are found chiefly on sandy seashores and in desert 

 places. The best-known genus is Mesemhryanthemum with about 350 

 species, of South African origin (Fig. 1593). They are mostly succulent 



Fig. 1593. — Mesemhryanthemunt spectahile. 

 Flower. 



