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TEXTBOOK OF BOTANY 



Annual rings 

 spring wood 

 Summer wooc 



Xylem rays 



Fig. 110. Diagram of a block of oak wood, magnified to show the arrangement 

 of tissues which underhes the patterns on pohshed wood surfaces. Courtesy of 

 World Book Co. 



When the cut passes through several annual rings, as in slab-cut boards, 

 the pattern is most striking. Xylem rays in oaks and some other trees are 

 prominent, and in quarter-sawed boards from such trees the rays appear 

 as the light-colored areas. 



If the annual rings are narrow, the wood is "fine-grained"; if they are 

 wide, "coarse-grained." Some patterns of wood have special names. The 

 "silver grain" of quarter-sawed oak refers to the large wood rays. If the 

 patterns are wavy in appearance, as they sometimes are in birch, cherry, 

 and chestnut, the wood is regarded as "curly grain." The best known is 

 the "bird's-eye grain" of certain maples. This is caused by the presence 

 of numerous partly dormant buds from which minute, embedded lateral 

 stems develop. These small "stems within a stem" are the "eyes" of the 

 wood seen in tangential section. 



The monocot stem. Since the stems of monocots were discussed with 

 those of dicots and conifers, some of the major facts about them may be 

 summarized. The vascular bundles are scattered throughout the stem 

 (Fig. 98) . No cambium, except temporary vestiges, occurs in the bundles. 



