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A TEXTBOOK OF THEORETICAL BOTANY 



Cycas revoluta (The Sago Palm) 



This interesting species has been called " a living fossil " on account of 

 its primitive characteristics. It is native to southern Japan and China, but 

 it is much the most widely cultivated of all Cycads, and specimens may be 

 found in cultivation all over the world. Its natural habitat is in open, sunnv, 

 well-drained situations (Fig. 711). 



Fig. 711. — Cycas revoluta growing on a hillside in southern Japan. 



{F7om a lantern ilide lent by Professor Chamberlain.) 



General Morphology 



When young the stem is almost tuberous, its apex sheathed in brown 

 scales and bearing a cluster of pinnate leaves 3 or 4 ft. long, and of hard, 

 leathery texture. The pinnae are closely set on the rachis and there is no 

 terminal pinna (Fig. 712). 



Growth is very slow, but in course of time the stem builds up a thick, 

 columnar trunk which is normally unbranched, except in certain cultural 

 varieties which produce lateral adventitious buds. The plant lives to an 

 age of several hundred years, and very old specimens with trunks nearly a 

 metre thick are known in the wild state. 



The old stem is sheathed in a hard armour of woody leaf bases, which 

 persist for many years, and as the leaves are formed in a close spiral succession 

 the bases cover the stem surface completely, as in the Male Fern. The 



