652 



METASPERMAE OP THE MINNESOTA VALLEY. 



The third column of the table above furnishes the largest 

 percentage figure of any of the tables. The 80.9 per cent, of 

 eastern- ranging monocotyledonous genera indicates sufficiently 

 the eastern preponderance of this taxonomic group, as repre- 

 sented in the valley of the Minnesota. The lower percentage 

 of the Metachlamydeae will be understood better in connection 

 with the following table: 



By a comparison of the two tables preceding it is noted 

 that the differences are widest between the Monocotyledones, and 

 narrowest between the Metachlamydeae. By genera, then, the 

 Monocotyledones are most evenly distributed north and south 

 while the Metachlamydeae are most evenly distributed east and 

 west. The evident importance of this fact, thus determined, lies 

 in the exact parallelism which it maintains with others derived 

 above. The Metachlamydeae, being peculiarly the central and 



