52 



LEAVES. 



[SECTION 7. 



132. In the other case (as in Fig. 74, 129-132), the veins branch off 

 from three, five, seven, or nine ribs, which spread from the top of the leaf- 

 stalk, and run through the blade like the toes of a web-footed bird. Heuce 

 these are said to be Palmateli/ or Digitately veined, or (since the ribs di- 

 verge like rays from a centre) Radiate-veined. 



133. Since the general outline of leaves accords with the frame-work or 

 skeleton, it is plain that feather-veined (or penni-veined) leaves will incline 

 to elongated shapes, or at least to be longer than broad ; while in radiate- 

 veined leaves more rounded forms are to be expected. A glance at the 

 following figures shows this. 



134. 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 



m 



J 



115 116 117 118 119 120 



for all other flattened parts as well, such as petals ; so that they make up a 

 great part of the descriptive language of Botany. It will be a good exer- 

 cise for young students to look up leaves answering to these names and 

 definitions. Beginning with the narrower and proceeding to the broadest 

 forms, a leaf is said to be 



Linear (Fig. 115), 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. 116), or both upwards and downwards. 



Oblong (Fig. 117), when nearly twice or thrice as long as broad. 



Elliptical (Fig. 118) is oblong with a flowing outline, the two ends alike 

 in width. 



Oval is the same as broadly elliptical, or elliptical with the breadth con- 

 siderably more than half the length. 



Ovate (Fig. 119), when the outline is like a section of a hen's egg 

 lengthwise, the broader end downward. 



Orbicular, or Rotund (Fig. 132), circular in outline, or nearly so. 



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

 may be 



Oblanceolate (Fig. 121) when of the lance-shaped form, only more tapering 

 toward the base than in the opposite direction. 



Spatulate (Fig. 122) when more rounded above, but tapering thence to a 

 narrow base, like an old-fashioned spatula. 



Fiq. 115-120. A series of shapes of feather-veined leaves. 



