III. A SPECIALIZED PLANT (e.g., The Bean Seedling} 1 



A . The plant as a whole: 



1. Examine the seedling given you and note that it is 



composed of an axis with appendages; the axis, of 

 root and shoot; the root, of a primary root with 

 branches (secondary roots); and the shoot, of a 

 main stem, bearing leaves. Has the main stem 

 branches? Is this true of all plants? What is the 

 difference between a stem and a branch? 



2. Describe fully the location of the leaves and their 



attitude on the stem. Do they occur on both the 

 main stem and its branches? The places on the 

 stem where leaves grow are nodes. The spaces 

 between the nodes are called internodes. 

 .3. Compare the size of the upper with that of the lower 

 angle made by the leaves with the stem. This 

 upper angle is called the leaf -axil (Latin axilla, 

 armpit). 



4. Do you find any structures in the leaf-axils? If so, 

 describe them. What are they? 



5. With what do the tips of the main stem and branches 



terminate? 



6. Describe any other outgrowths of stem or branches. 



7. Make a drawing of the plant as large as your draw- 



ing paper will permit, showing all parts referred to 

 above. 



1 This study may or may not be omitted, depending upon the previous 

 preparation of the students, and the time available. 



16 



