FLORA OF WASHINGTON AND VICINITY. 



37 



of the country, or from that of the country at large. To institute com- 

 parisons with other local floras would, of course, carry me much too far 

 for the general purpose of this pajier, but it is both more interesting 

 and more practicable to confront a few of the above results with similar 

 ones drawn from a consideration of a large part of the United States.. 

 For this purpose, as not only most convenient but as least liable to em- 

 brace facts calculated to vitiate the comparisons, I have chosen that 

 portion of the United States situated east of the Mississippi River and: 

 for the most part well covered by Gray's Manual of Botany for the 

 northern jiortion and Chapman's Flora of the Southern States for the 

 southern portion. The plants described in these works are conveniently 

 collected into one series by the second edition of Mann's Catalogue, pub- 

 lished under the supervision of the authorities at Cambridge in 1872.. 

 Many changes have since been made in the names, &c., and a few new 

 species added, but these are not sufficient to affect the general conclu.- 

 sions to be drawn from the following comparative tables. 



Comparison of Species and Varieties. 



The number of species and varieties of vascular plants enumerated 

 in the work above referred to is 4,034, of which the 1,249 of the flora of 

 Washington constitute 31 per cent. The comparison by groups is as 

 follows : 



Series, Classes, and Divisions. 



PolypetalsB 



GamopetaliB 



Total DichlamydejB 



Monochlamydeae (Apetalse). 



Total Dicotyledons 



Monocotyledons (Endogens) 

 GymnospermsB 



Total Phsenogamia 



Cryplogamia 



Total Vascular Plants. . 



Species and va- 

 rieties in the — 



PS 



el 



©02 



1,115 

 1,314 



2,429 

 349 



2,778 

 1,034 



28 



3,840 

 194 



4,034 



356 

 389 



745 

 124 



1,207 

 42 



1,249 



869 [ 31 



331 1 32 



7 25 



31 

 22 



Comparison of Oenera. 



The whole number of genera in the flora of the Eastern United States- 

 is 1,0G5. That of the Flora Columbiana, as already stated, is 527. This 

 is over 49 per cent., a much larger proportion than was shown by a com- 



