LEA VES. 



kinds of herbs and trees is called phyllotaxis.* When 

 leaves grow two or more together at the same level of 

 the stem, they are in whorls or whorled (Fig. 56). 

 Now if you look again at the leaves upon a common 

 dead nettle you will see that they are arranged in 

 pairs, each pair con- 

 sisting of two oppo- 

 site leaves. Each 

 pair grows so that its 

 two leaves are over 

 the spaces between 

 the two leaves next 

 below it. This 

 arrangement of leaves 

 is called decussate, f 

 You can find exam- 

 ples of it in the 

 privet (Fig. 55), 

 honeysuckle, horse 

 chestnut, and many 

 others. You will learn 

 more about Phyllo- 

 taxis or leaf arrange- 



Fig. 56. Woodruff. (Aspemla odoi-ata}. 



merit when you are showing leaves in whorls, 



older. 



But before we leave the position of the leaves we 



* From the Greek "/////<>," a leaf, and "taxis? order, arrange- 

 ment. 



t From the Latin " decusso" I cut crosswise. 



