FLORA OF WASHINGTON AND VICINITY. 35 



Large orders. 



The 16 largest orders, arranged according to the number of species,, 

 are as follows : 



Orders. 



Species and 

 varieties. 



1 CompositiB 



2 Gramineaj 



3 I Cyperaceffl 



4 j LeguminoScB 



5 I RosacefB 



6 I LabiatfB 



7 j Cruciferaj 



8 I ScrophulariacesB 



9 ' Filices 



10 Kauunculaceas . . 



11 j Ericaceae 



12 Cupuliferoe 



13 ; Orchidaceas 



14 Liliaccse 



15 : PolygonacesB 



16 I Um'beUiferse 



14» 

 110 

 108 

 57 

 46- 

 42 

 33 

 32 

 30 

 27 

 26 

 26 

 24 

 24 

 23; 

 22 



The whole number of systematic orders represented in our district is 

 116, of which these 16 or 14 per cent, furnish 55 per cent, of the genera 

 and 62 per cent, of the species. 



Large genera. 



The 15 largest genera, arranged according to the number of plants^ 

 are the following : 



Thus 15, or less than 3 per cent, of the genera, furnish 271, or nearly 

 22 per cent, of the species. 



Introduced Species. 



The whole number of introduced plants enumerated in the subjoined 

 catalogue is 193, of which 15 are supposed or known to be indigenous 



