334 



PLANT MORPHOLOGY 



Fig. 283. 

 D.C. 



A large tree of Ginkgo biloba on the grounds of the White House, Washington, 



tribution (Fig. 258). The most important Mesozoic genera were Baiera 

 and Ginkgo itself, both represented by many species. 



Sporophyte. Ginkgo is a tree with the general habit of a conifer (Fig. 

 283). It is excurrent when young, becoming round-topped in old age. 

 Under favorable conditions, it may reach a height of 30 m. There are 

 two kinds of branches: long branches of unlimited growth bearing scat- 



