STEMS 



CHAPTER IV 



STEMS 



I. Take a piece of Sunflower stem, several inches long, 

 examine and notice : 



1. The regular succession of nodes and internodes. (For 



definitions turn back to IV, 6, under Seedlings, 

 p. 12.) 



2. The consistency of the stem (in this case not very 



woody) . 



3. How long does the Sunflower stem live? 



4. The Sunflower is an herb and its stem is said to be her- 



baceous. Why? i / J^\JtA^^ 



5. Make a sketch of this piece of stem. VW- 



II. Examine a thin section of the Sunflower stem, cut 

 transversely. (These sections are best, if prepared by the 

 teacher and examined under the lens of the dissecting 

 microscope, or under the lower power of a compound 

 microscope.) Notice : 



1. The central softer portion, the pith, made up of larger 



or smaller polygonal spaces, the cells. 



2. The ring of rather irregularly shaped bodies surrounding 



the pith, the woody or vascular bundles. 



3. The outer bark or cortex, including everything outside of 



the vascular bundles, except 



