95^ 



A TEXTBOOK OF THEORETICAL BOTANY 



the middle portion of the leaf. The former are described as pinnatifid 

 or palmatifid and the latter as pinnatisect or palmatisect respectively. 

 These and certain other special types of division in simple leaves are 

 illustrated in Figs. 938 and 939. 



NiJ^ 



B 



D E F 



Fig. 938. — Types of Pinnate division in simple leaves. A, Runcinate ; Taraxacum. 



B, Pinnatifid ; Setiecio vulgaris. C, Pinnatisect ; Papaver. D, Bipinnatifid ; Seuecio 

 jacobaea. E, Bipinnatisect ; Achillea. F, Lyrate ; Lapsana. 



The common forms assumed by compound leaves are shown in Fig. 940. 

 Some of these are complicated by a higher degree of subdivision than simple 

 pinnation, the pinnae being themselves divided into pinnules and these again, 

 sometimes further subdivided, producing bipinnate or tripinnate types. 



Variations in the relative length and breadth of simple leaves are 

 illustrated in Fig. 941. The narrowest leaves, such as those of grasses, with 

 parallel sides, are called linear while other varieties are given in the Figure, 

 together with some of the principal variations in the attachment of leaf and 

 stem, as described above. 



