94 



THE LEAF 



Acute, ending in an acute angle or not prolonged point; Fig. 102. 



Obtuse, with a blunt or rounded apex; as in Fig. 103, etc. 



Truncate, with the end as if cut off square ; as in Fig. 104. 



Retuse, with rounded summit slightly indented, forming a very 

 shallow notch, as in Fig. 105. 



Emarginate, or Notched, indented at the end more decidedly ; as in 

 Fig. 106. 



Obcordate, that is, inversely heart-shaped, where an obovate leaf is 

 more deeply notched at the end (Fig. 107), as in White Clover and 

 Wood-sorrel ; so as to resemble a cordate leaf inverted. 



101 102 



101-109. Forms of the apex of leaves: 101, acuminate; 102, acute; 103, ob- 

 tuse ; 104, truncate ; 105, retuse; 106, emarginate ; 107, obcordate ; 108, 

 cuspidate, 109, mucronate. 



Cuspidate, tipped with a sharp and rigid point ; as in Fig. 108. 



Mucronate, abruptly tipped with a small and short point, like a 

 mere projection of the midrib ; as in Fig. 109. 



Aristafe, Awn-pointed, and Bristle-pointed, are terms used when this 

 mucronate point is extended into a longer bristle-form or slender 

 appendage. 



The first six of these terms can be applied to the lower as w^ell as 

 to the upper end of a leaf or other organ. The others belong to the 

 apex only. 



170. As to degree and nature of division, there is first of all the 

 difference between 



Simple leaves, those in which ^e blade is of one piece, however 

 much it may be cut up, and " ^^ 



Compound leaves, those in which the blade consists of two or more 

 separate pieces, upon a common leafstalk or support. Yet between 

 these two kinds every intermediate gradation is to be met with. 



171. As to particular outlines of simple leaves (and the same 

 applies to their separate parts), they are 



Entire, when their general outline is completely filled out, so that 

 the margin is an even line, without teeth or notches. 



Serrate, or Saw-toothed, W'hen the margin is cut into sharp teeth, like 

 those of a ripsaw^ that is, pointing forwards; as in Fig. 110. 



Dentate, or Toothed, when such teeth point outwards, instead of 

 forwards; as in Fig. 111. 



Crenate, or Scalloped, when the teeth are broad and rounded ; as in 

 Fig. 112. 



