750 



METASPERMAE OF THE MINNESOTA VALLEY. 



Passing next to the habitat elements a similar table of range 

 statistics may be considered. 



From the above table it is seen immediately that the aquatic 

 plants are more general in their continental distribution than 

 the marsh and swamp plants and these in turn more generally 

 distributed than the drier- soil plants. The aquatics, however, 

 are strongly eastern, presenting indeed their total number in 

 this range; the marsh and swamp plants are only less eastern 

 while the easternness of the drier-soil plants is the least of the 

 three. The marsh-plants lead in northernness while the drier- 

 soil plants excel in southernness. In westernness the ratios are 

 similar to those of easternness, owing to the differences of 

 general distribution. Comparing each element with the total 

 flora we may note first the aquatics. 



The aquatic element exceeds the total flora in all four ele- 

 ments of range. This indicates, in an accurate and instructive 

 manner, the widely distributed character of aquatic plants. 

 The southern per cent, of aquatic Metachlamydeae is, however, 

 less than the southern per cent, of all Metachlamydeae, while 

 the northern per cent, is considerably greater. Again there is 



