THE PLANT GROUPS 145 



f. Drawings. 



(1) Construct outline drawings of sectors of the young 



and old stems of geranium. 



(2) Detail the cork cambium and its products. 



(3) Detail a small portion of the vascular cylinder of a 



section of the older portion of the stem. 



g. Long sections. If long sections of geranium are avail- 



able, study the tissue of the xylem, noting especially 

 the structure of the ducts. Draw spiral and dotted 

 ducts and adjacent tissues. 



SUMMARY 



Summarize the structure of the geranium stem, modifying the 

 summary given for Sal via (p. 108 of text), as you think it should 

 be, to characterize the primary structure and secondary growth 

 of a geranium stem. 



WOODY TYPE (ANATOMY) 



1. Review the work previously done on the structure and 

 growth of trees in Part I of the text (Fig. 55 and 

 discussion). 



a. Comparisons. In what respects is the woody dicotyle- 



don better equipped for conducting water and for stor- 

 ing food than the spruces and pines ? In what respects 

 does it differ from the herbaceous dicotyledon ? 



b. Summarize the distinctive features of the woody dicoty- 



ledon which characterize it as the most highly 

 organized living plant. How is it adapted structur- 

 ally to perform the functions of support, storage, and 

 conduction ? Where are the supporting, storage, and 

 conducting tissues located in trees and shrubs? 

 How do they differ in this respect from herbs like 

 Salvia and geranium ? 



