92 



THE LEAF 



TERMS USED IN THE DESCRIPTION OF LEAVES 



[Inserted for reference use by classes making the determination of 

 plants a part of their course.] 



167. Forms of leaves as to general outline. — It is necessary to 

 give names to the principal shapes, and to define them rather precisely, 

 since they afford easy marks for distinguishing species. The same 

 terms are used for all other flattened parts as well, such as petals ; so 

 that they make up a great part of the descriptive language of Botany. 

 Beginning with the narrower and proceeding to the broadest forms, a 

 leaf is said to be 



Linear (Fig. 83), when narrow, several times longer than wide, and 

 of the same breadth throughout. 



Lanceolate, or Lance-Shaped, when conspicuously longer than wide, 

 and tapering upwards (Fig. 84), or both upwards and downwards. 



Oblong (Fig. 85), when nearly twice or thrice as long as broad and 

 of uniform breadth. 



Elliptical (Fig. 86), when similar to oblong but with continuously 

 rounding sides. 



Oval, when broadly elliptical, or elliptical with the breadth con- 

 siderabl}^ more than half the length. 



Ovate (Fig. 87), when the outline is like a section of a hen's egg 

 lengthwise, the broader end toward the stem. 



S3 84 



83-88. A series of shapes of feathered- veined leaves : 83, linear ; 84, 

 lanceolate ; 85, obloug ; 86, elliptical ; 87, ovate ; 88, cordate. 



Orbicular, or Rotund (Fig. 97), circular in outline, or nearly so. 



A leaf which tapers toward the base instead of toward the apex 

 may be 



Oblanceolate (Fig. 89), when of the lance-shaped form, only more 

 tapering toward the base than in the opposite direction. 



Spatulate (Fig. 90), when more rounded above, but tapering thence 

 to a narrow base, like an old-fashioned spatula. 



Obovate (Fig. 91), when inversely ovate, that is, ovate with the nar- 

 rower end toward the stem. 



Cuneate,ov Cuneifoi^m, that is. Wedge-shaped (Fig. 92), broad above 

 and tapering by nearly straight lines to an acute angle at the base. 



