PHILOSOPHICAL SOCIETY OF WASHINGTON. 



101 



* Including the Betulacese. 



Comparisons have already been made of our local flora with that 

 of Essex county, Massachusetts, which contains so nearly the same 

 number of plants. In examining the percentages in the above 

 table, these distinctions are equally manfest. In both divisions of 

 the Dichlamydece, and also in the Dicotyledons, and the total 

 Phcenogamia, our flora is richer than that of Essex county, while 

 in the Monochlamxjdece, the Monocotyledons, the Gymnosperms, and 

 the Cryptogams, it falls below. In the Compositce, Leguminosce, 

 Labiatce, Or'uciferce, Swophalaricece, Cupuliferce, and a few other 

 orders it is in excess, while in the Graminece, Gyperacece, Rosacece, 

 Filices, &c, the Essex flora leads. 



In the comparison with the flora of the State of Illinois, one is 

 struck by the marked similarity in the position of the groups, not- 



