70 



THE LEAF 



{b) Forms of blade.— Ih^ outline of the blade of the leaf may 

 assume almost any geometrical figure (Fig. 30). When it is 



Fig. 30. — Common Forms of Leaves : i, Linear ; 2, lanceolate ; 

 3, ovate ; 4, elliptical ; 5, cordate ; 6, sagittate ; 7, hastate ; 8, 

 reniform ; 9, spathulate. 



much elongated and narrow as in grasses it is termed a linear leaf. 



It may also be lanceolate as in the narrow-leaved plantain ; ovate 

 egg-shaped); elliptical; reniform or kidney- 

 shaped ; cordate (heart-shaped) ; sagittate 

 (arrow-shaped) ; spathulate (spoon-shaped) as 

 in the daisy ; and hastate (halberd-shaped) as 

 in sheep's sorrel. 



(c) Leaf-margin. — The edge of the leaf-blade 



is sometimes entire as in privet; or variously 



indented with larger or smaller incisions. (Fig. 



31.) Leaves having margins like the edge of 



, , .a saw are serrate; when the small tooth-like 



Fig. 31. — Leaf-margin: ... 



I, Entire ; 2, serrate ; 3, mcisions Stand out at right angles to the edge 



dentate ; 4, crenate. - , , ^ . . , .,1 , , 



of the leaf it is described as dentate ; the term 



