THE COMPOUND LEAF. 



Undulate. 



Aristate or awn-pointed, like mucronate but with a longer and more 

 or less bristle-shape point. 



Cuspidate, when the point is sharp and rigid. 



Truncate, when an extremity is so blunt as to seem cut squarely off. 

 Retuse, when slightly notched. Emarginate, when more decidedly 

 notched. Cordate or heart-shaped, when deeply emarginate at the base. 

 Obcordate, when deeply emarginate at the apex. 



36. While the bases of opposite sides of a leaf usually develop about 

 uniformly it is not always the case, and such leaves are spoken of as 

 oblique or inequilateral at base. They are quite characteristic of the 

 Elms, and Fig. 15 shows some of these 



leaves, but there the obliquity is not so 

 marked as is often the case. 



37. The Margin of the Leaf, as 



shown in Fig. 16 is 



Entire, when of even continuous out- 

 line without projections or indentations. 



Serrate, when furnished with small and 

 sharp teeth, pointing towards the apex, 

 like the teeth of a saw. 



Dentate, when the teeth are small and 

 point outward from the center of the leaf 

 instead of forward. 



Incised or jagged, when the teeth are 

 long, sharp and irregular. 



Crenate, similar to dentate, but with 

 broad and rounded teeth. 



Undulate, wavy or repand, when slightly 

 scalloped with wavy outline. 



Sinuate, same as undulate, but with 

 deeper indentations, which here and in 

 the following classes are called sinuses. 



Lobed, when the sinuses are more or 

 less rounded and deeper, but entering not 

 more than half way to the midrib or base 

 of the leaf. The term "lobed" is often 

 applied in a general way, regardless of 

 the depth or form of the sinuses, when 

 the leaf is cut into a definite number of 

 lobes, and it is said to be tivo-lobed, five- 

 lobed, many-lobed, etc., as the case may be. 



Cleft, same as lobcd, but with usually 

 narrow and pointed sinuses entering half 

 way to the midrib or base. 



Parted, when the incisions enter nearly to the midrib or base. 



Divided, when they reach the midrib or base; and this leads us to the 

 consideration of 



38. The Compound Leaf a leaf consisting of several blades, with 

 a common petiole or main leaf-stalk (Figs. 17 and 18), and in this cliffer- 



Fig. 16. Forms of Margins of Leaves. 



Parted. 



Divided. 



FIG. 



