Climate of Middle Illinois. 



71 



A number of local floras and such of larger districts of the same geo- 

 graphical latitude or longitude are given in the following table, but it 

 must be remarked that all mere varieties and all introduced species are 

 excluded, and that the figures mean the number of the entire states, even 

 if they, like New York state, Ohio, Illinois, and Wisconsin, belong to dif- 

 ferent natural floral districts: 



The comparatively large number of species in Illinois is readily 

 explained by the wide extension of this state in a south-north . direction 

 over 5° of latitude. The number of species in * Michigan, Wisconsin, 

 Arkansas, and particularly in Colorado may really show greater figures, 

 as those states are apparently not so thoroughly explored in all parts. 



Generally the eight or ten largest orders make up half of the whole 

 number of vascular species of a floral district. The following tables will 

 show the per mille of species for each of the largest orders: 



Ohio. 



Compositfe 122 



Cyperacese 95 



Gramineee 65 



LeguminosiB 40 



Eosacese 36 



OrcbidaceEB 32 



Filices 30 



Ranunculacese 29 



Labiatse 28 



Liliaceae 28 



Massachusetts. 



Cyperacese 116 



Compositse 108 



Gramineee 73 



Kosacese 38 



Ericaceae 33 



Pilices 32 



Legurainosse 26 



Orchidacse 26 



Scrophulariacese 24 



Labiatse 22 



New ' YorJt. 



Cyperacefe 113 



Compositse 104 



Graminese 79 



Eosacese 36 



Leguminosse 34 



Ericacese 30 



Filices 30 



Orchidacese 29 



Scrophulariacese ... 25 



LabiatsB 25 



505 



505 



* * Michigan means here the lower peninsula, and the flora is taken from the 

 first Eeport of Geological Survey of Michigan, 1861. The flora of "W.isconsin after 

 Lapham's Catalogue in Transactions of the Wisconsin State Agricultural Society, 

 1863, with two additions by Hale. The flora of Arkansas is after, Lesquereux' 

 Catalogue in Arkansas Geological Survey ^1860). The flora of Colorado is after 

 Porter and Coulter (1874). 



