32 PHARMACEUTICAL BOTANY 



Parallel Venation is typical of the Monocotyledons, as Palms, 

 Lilies, Grasses, etc. 



Reticulate or Netted Veins characterize the Dicotyledons, as 

 the Poplar or Oak. 



Pinni-veined or Feather-veined leaves consist of a mid-vein 

 with lateral veinlets extending from mid-vein to margin at frequent 

 intervals and in a regular manner. Ex. : Calla. 



Palmately Veined leaves consist of a number of veins of nearly 

 the same size, radiating from petiole to margin. Ex. : Maple leaf. 



The Forms of Leaves. — Simple leaves are those having a single 

 blade, either sessile or petiolate. 



Compound leaves are divided into two or more distinct subdivi- 

 sions called leaflets, which may be either sessile or petiolate. 



Simple leaves and the separate blades of compound leaves are de- 

 scribed as to general outline, apex, base, marginal indentations, surface 

 and texture. 



(a) General Outline (form viewed as a whole without regard to 

 indentations of margin). Dependent upon kind of venation. 



When the lower veins are longer and larger than the others, the leaf 

 is Ovate, or Egg-shaped. Parallel-veined leaves are usually linear, 

 long and narrow of nearly equal breadth throughout, or lanceolate, like 

 the linear with the exception that the broadest part is a little below the 

 centre. 



Elliptical, somewhat longer than wide, with rounded ends and 

 sides. Ex.: Leaf of Pear. 



Oblong, when longer than broad, margins parallel. Ex. : Matico. 



Oblique, margin longer on one side than the other, as the Hamamelis 

 and Elm. 



Orbicular, circular in shape. Ex.: Nasturtium. 



Peltate, or shield-shaped, having the petiole inserted at the 

 centre of the lamina. Ex.: the Nasturtium, Podophyllum. 



FiLiPORM, or thread-like, very long and narrow, as Asparagus 

 leaves. 



Ovate, broadly elliptical. Ex.: Digitalis. Obovate, reversely 

 ovate. 



Oblanceolate, reversely lanceolate. Ex. : Chimaphila. 



Cuneate, shaped like a wedge with the point backward. 



Spatulate, like a spatula, with narrow base and broad rounded 

 apex. Ex.: Uva Ursi. 



