STUDY 14. 
AN EQUISETUM, £. Arvense ; Common Horsetail. 
A. The Vegetative Portion. (An erect branching form.) 
1. 
_ 
ee 
8. 
Identify nodes and internodes of the main axis and 
its branches. 
Are there leaves? If so, what is their form and 
arrangement ? 
Are all of the internodes of the same length? If 
not, why? Are the internodes smooth or rough 
(m.)? Why? 
Study longitudinal and transverse sections to dis- 
cover whether the stem is solid or hollow and 
where. 
How do the internodes join each other? 
Are the walls solid or hollow? 
Make drawings: (a) two or more internodes des- 
ignating all structures; (6) a longitudinal section 
through a node showing the leaf attachments and 
the union of internodes; (¢) a transverse section 
of an internode designating its parts. 
What is the form and origin of the roots? (Draw.) 
B. The Reproductive Portion. (Sporophyte.) (Speci- 
men without branches. ) 
1. How does it differ in color and structure from the 
vegetative portion? 
2. The distal spindle-shaped fruiting spike (strobilus) 
consists of spore-bearing “modified leaf structures,” 
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