Margin and Apex of Leaves 



77 



Sometimes the teeth are themselves divided, and we get 

 bicrenate, duplico-dentate, and biserrate margins. 



If the margin of the leaf be covered with numerous hairs 

 (fig. 114), it is ciliate. If there be alternate concavities and 

 convexities larger than crenated indentations, the margin is 

 sinuate (fig. 115). 



When the teeth are very long and sharp, the margin is spiny 

 (fig. 116), and when the margin is very irregular, as in the 

 garden Endive and curled Dock, it is crisped. 



Fig. 114.— Ciliate leaf 

 of the Beech. 



Fig. IIS. — Sinuate 

 leaf of f he Oak. 



Fig. ii6.— Spiny leaf 

 of the Holly. 



3. Incision. — We apply this term if the margin be more 

 deeply indented than in the instances already described. If 

 the indentations reach to midway between the margin and the 

 midrib or petiole, we speak of them as fissures, and the por- 

 tions of leaf between them as lobes, and the leaf is said to be 

 bt-, tri-, etc., -fid. If the divisions go nearly to the base, or 

 midrib, they are partitions, and the leaf is bi-, tri-, &c., -partite. 

 If quite down to the midrib or base segments, the leaf is bi-, 

 tri-, &c., -sected. (For further remarks on this point see under 

 the head of Outline.) 



4. Apex. — If the apex of the leaf be rounded (fig. 115), i 

 is obtuse or blunt. If it be sharp pointed (fig. no), it is acute, 

 and if it gradually tapers to a point (fig. 117), it is acuminate. 

 When there is a rounded head, and a broad shallow notch in 

 it, the apex is retuse, and when the notch is more triangular 



