PHYLLOTAXY 39 



CHAPTER VII 



PHYLLOTAXY 



PHYLLOTAXY is the arrangement of leaves upon the stem. 

 Leaves are arranged upon the stem in one of two ways as 

 illustrated by Fuchsia ( I) and by Begonia ( IV) 



I. Examine a branch of some species of Fuchsia and 

 notice : 



1. The number of leaves at each node. 



2. The relative arrangement of the leaves at two successive 



nodes. 



3. Make a sketch to show these points. 



4. The arrangement of leaves just studied is a good example 



of the opposite or cyclical arrangement. 



II. Look at the branch of Fuchsia from above and 

 notice : 



1. The four vertical ranks of leaves. 



2. Make a diagram to represent this. 



III. Examine a plant of the common Bedstraw or Cleavers 

 (species of Galium) and notice : 



1. The number of leaves (3 to 8 or 10) at each node. 



2. The relative arrangement of the^ leaves at two successive 



nodes. 



