GINKGOALES 



193 



The tissue is rather uniform throughout the leaf, there being no 

 well marked palisade in the leaves of the spur shoots. The leaves on 



Fig. 206. — Ginkgo biloha: tracings of leaves from a single tree at the University of 

 Chicago. The leaves in the upper part of the figure are from long shoots; and the ten 

 lower leaves are from spur shoots; one-third natural size. 



the long shoots, especially the larger leaves, have a well-marked 

 palisade. The stomata are on the abaxial surface and are slightly 

 sunken (fig. 210). 



The root. — The root has a diarch cylinder, except when there are 

 three cotyledons, in which case it is triarch. 



