64 



PALMATE VENATION 



[CH. 



In typically palmate venation all the principal ribs 

 behave as primaries and must be regarded as such. 

 These primaries arise, together with the midrib, from 

 one point at the base of the leaf where it joins the 

 petiole, and diverge thence in a radiating manner, as is 

 well seen in the Norway Maple (Fig. 15). 



The following afford good examples of true palmate 

 venation : 



Fig. 23. Leaf of Guelder Rose, Viburnum Opulus, showing palmate- 

 pinnate venation (D). 



Two varieties of the palmate type stand out when we 



