MORPHOLOGY, GENETICS AND BREEDING 43 



cotyledonary lateral, subtended by reduced foliar scales known as 

 cataphylls. These are found as the first two foliar organs of all lateral 

 axes. The cataphyllar internodes are usually short and on the lower 

 branches are frequently covered with soil during cultivation. 



In Virginia type peanuts the first reproductive branch generally ap- 

 pears in the axil of the first foliage leaf on one of the cotyledonary laterals. 

 No reproductive branches occur directly on the main stem in Virginia. 

 A reproductive branch may occur in the axil of the second cataphyll but 

 none has been reported or observed in the axil of the first cataphyll. The 

 first reproductive branches in Spanish and Valencia types occur at the 

 first cataphyllar nodes on the cotyledonary leiterals. Later reproductive 

 branches also occur on the main stem. 



VEGETATIVE STRUCTURE OF THE MATURE PLANT 



A detailed anatomy of the mature peanut plant has not been written. 

 The general morphology, habit of growth, branching habit, and general 

 appearance of the plant have been described with varying degrees,' of 

 thoroughness. Much of this description is to be found in the taxonomic 

 treatments of the genus and its relatives. Although we are not primarily 

 concerned here with the systematics of peanuts, we find the published 

 descriptive accounts of the species one of our best sources of general 

 morphological information. 



Root 



Hoehne (34) has described the genus as perennial. The root systems 

 of all the wild species develop much-branched, woody structures and all, 

 including our cultivated form, last more than one year. In A. hypogaea 

 the root system may penetrate to a depth o f 3 to 4 feet in cultivated 

 fields (Yarbrough 76). In some wild species the root systems become 

 tuberous and fleshy (figure 11). This characteristic is not confined to A. 

 tuber osa but is also found in A. marginata (34). When grown in the 

 United States, wild species received from South America show variable 

 development of the tuberous habit, but even in forms generally not 

 thought to possess tubers this character is somewhat apparent. Of the 

 species seen by the authors, only in A. hypogaea do the roots appear to 

 be entirely non-tuberous. At present '^c (Jo not know whether or not 

 this character would develop in specimens of A. hypogaea grown for sev- 

 eral years. Hoehne (34) considered the tubers to be food storage organs 

 which assist in carrying the plants pv^r unfavorable periods of the year, 



