46 



HOW PLANTS GROW. 



129. Parallel-veined leaves, we see, are of two sorts; — 1. those with the veins or 

 nerves all running from the base of the leaf to the point (Fig. 85) ; and, 2. those 

 .where they mostly run from the midrib to the margin, as in Fig. 86. Netted-veined 

 leaves likewise are of two sorts, the Feather-veined and the l^adiate-veined. 



130. Feather-veined (al- 

 so called pinnately veined) 

 leaves are those in which 

 the main veins all spring 

 from the two sides of one 

 rib, viz. the midrib, like the 

 plume of a feather from 

 each side of the shaft. Fig- 

 ures 82, 88-97, 120, 122, 

 &c. represent feather-veined 

 leaves. 



131. Radiate- Veined (al- 

 so called palmately veined) 

 leaves are those which have 

 three or more main ribs ris- 

 ing at once from the place 

 where the footstalk joins the 

 blade, and commonly diverg- 

 ing, like rays from a centre ; the veins branching otf from these. Of this sort are 

 the leaves of the Maple (Fig. 84), Mallow, Currant, Grape- Vine, and less dis- 

 tinctly of the Linden (Fig. 83). Such leaves are generally roundish in shape. It 

 is evident that this kind of veining is adapted to round leaves, and the other kind 

 for those longer than wide. 



132. Shapes of leaves. As to general shape, the following are the names of the 

 principal sorts. (It will be a good exercise for students to look up examples which 

 fit the definitions.) 



Linear ; narrow, several times longer than wide, and of about the same width 

 throughout, as in Fig. 87. 



Lance-shaped or Lanceolate ; narrow, much longer than wide, and tapering up- 

 wards, or both upwards and downwards, as in Fig. 88. 



Oblong ; two or three times longer than broad, as in Fig. 89. 



■allel-veinef' Leaves 



