178 MORPHOLOGY AND LIFE HISTORY 



C. The Shoot: 



1. General. 



(a) Note its division into a main, thickened under- 

 ground part (rhizome) , bearing numerous roots, 

 and a long slender aerial branch. 



2. The Rhizome. 



(a) Describe its attitude (horizontal or erect), and 

 its general appearance. Compare Trillium 

 with the fern in this respect. 



(b) Are there branches, besides the aerial branch? 



(c) Note the thin membranous scales near the 

 apical end. Record their number and position. 

 Carefully remove them with the scalpel. What 

 purpose may they serve? What is their 

 homology? Make a drawing of one (X i). 



(d) Observe the nodes and internodes. What 

 do the nodes represent? Note the remnants of 

 the old scales at each node. Compare the 

 lengths of the internodes. What is the mean- 

 ing of this? 



(e) Describe any other scars on the rhizome. Are 

 they on nodes or internodes? What do they 

 represent? 



(/) State, with reasons for your opinion, the age 

 of your specimen. 



3. The Aerial Branch. 



(a) Describe its general appearance, shape, length 

 (compare several different specimens), color- 

 ation (color-pattern), and presence or absence 

 of branches. 



(b) At which end of the rhizome is it borne? Is 

 it a terminal or a lateral outgrowth? Is it an 

 axillary organ (i.e., borne in the axil of a leaf), 

 or not? On a node or an internode? 



