THEIR STRUCTURE AND FORMS. 



95 



two elements of the structure are correlated. Descriptive terms 

 applied to leaves are equally applicable to all expanded organs 

 or parts, and indeed to all outlines. Some leading forms are 

 here enumerated ; and all are defined in the Glossary. 



181. As to general Circumscription, proceeding from narrower 

 to broader shapes, and then to those with either narrowed or 

 notched base, leaf-blades are 



Linear, when narrow, several times longer than wide, and of 

 about the same breadth throughout. (Fig. 167.) 



Lanceolate, or Lance-shaped, when several times longer than 

 wide, and tapering upwards (Fig. 153, 168), or tapering both 

 upward and downward. 



Oblong, when nearly twice or thrice as long as broad. (Fig. 169.) 



Elliptical, oblong with a flowing outline, the two ends alike 

 in width. (Fig. 170.) 



Oval, the same as broadly elliptical, or elliptical with the 

 breadth considerably more than half the length. 



Ovate, when the outline is like a section of a hen's-egg length- 

 wise, the broader end being downward. (Fig. 171, 155.) 



Orbicular, or Rotund, circu- 

 lar in outline, or nearly so. 

 (Fig. 160.) 



Obovate, inversely ovate, or 

 ovate with the narrower end 

 toward the base, the broader 

 upward. (Fig. 175, 145.) 



Cuneate, or Cuneiform, that is, Wedge-shaped, broad above arid 

 tapering by straight lines to an acute base. (Fig. 176, 148.) 



Spatulate, rounded above, long and narrow below, like a 

 spatula. (Fig. 174, 147.) 



Oblanceolate, inverted lance-shaped, i. e. such a lanceolate 

 leaf as that of Fig. 168, but with the more tapering end at base, 

 as in Fig. 173. To those who restrict the term lanceolate to the 

 sense of a narrow leaf tapering equally in both directions, the 



FIG. 167-176. Outlines of various simple leaves. 



