90 



BOTANY: PRINCIPLES AND PROBLEMS 



In certain herbaceous plants the terminal bud produces a 

 flower or flower-cluster, and the growth of the stem in length 

 usually ceases at this point. Such deterininaie growth is not 

 common among wood}^ plants, however, and their stems continue 

 to elongate indefinitely. 



Leaves.- — Leaves are borne throughout the length of the stem 

 in herbaceous plants and on the twigs of the current year's 



I I.,. 41. A.^hiiih. 'I'hi^ Uhiv {SyruKja vubjarci). 



growth in woody forms (Fig. 44). That point on a stem at which 

 a leaf is attached is called a node and the region between two nodes, 

 an internode (Fig. 43). The position of the node also governs the 

 position of the lateral bud, for such a bud normally arises only 

 in the leaf axil, or upper angle between leaf and stem. 



The arrangement of leaves on the stem, or its phyllotaxy, 

 may display many different types. If but one leaf occurs at a 

 node the next one above it arises from the other side of the stem, 

 and the arrangement is thus an alternate one (Fig. 44). These 



