Fig. 251. Genealogical tree of plant life 



This diagram is intended to suggest the common origin of all plant forms, with the 

 constant progressive departure from ancestral types, now in one direction and now in 

 another, like the branching of a tree. Lowei- and higher mean nearer to or farther from 

 the original types. The closer together two forms are on a given branch, the more 

 closely related they are considered (cf. Fig. 252) 



