54 



Elementary Work in Botany. 



EXERCISE 31. 



The Forms of Leaf-Margins, Apexes, and Bases. 



Again classify all your leaves according to form. Such 

 forms as triangular, wedge-shaped (cuneate), sword-shaped^ 

 fiddle-shaped, fan-shaped do not need to be defined here. 



Fig. 44. a. lanceolate, b. Oblarceolate. c. SpaMilate. d. Ovate, e. Cordate. /. Reniform. 

 g. Cimeter-shaped. fi. Halberd-shaped, i. IJared at base. 



With the help of Fig. 45 name the margins of your leaves. 

 Observe that a serrate margin becomes crenate if the teeth 

 are rounded. If they are but slightly rounded then call 

 the margin crenate-serrate. Margins may have large teeth 

 which are themselves toothed. Thus we have doubly serrate, 

 doubly dentate, etc. The words coarsely and finely are used 

 to express conditions varying from the type. Note the 

 apexes. When about as sharp as in the leaf at h, Fig. 44, 

 they are acute. In the same Fig. a, e, and^ are acuminate, 

 c and d are obtuse. When the end seems as if it were cut 

 off square it is truncate. A shallow notch in the end of an 

 obtuse leaf makes it emarginate. A cuspidate leaf ends in 

 a short rigid point (a, Fig. 43). A mere prolongation of 



