PHILOSOPHICAL SOCIETY OF WASHINGTON. 89 



The percentages of the total are as follows : 



Polypetalce 33 29 



Gamopetake 32 31 



Total Dichlamydeae 65 60 



Monochlamydece (Apetalse) 9 10 



Total Dicotyledons 74 70 



Monocotyledons 21 26 



Gymnosperma? (Conifera?) 1 1 



Total Phasnogamia 96 97 



Cryptogamia 4 3 



Large Orders. 



The sixteen largest orders arranged according to the number of 

 species, are as follows : 



~ Species and 



Genera. r . .. 



varieties. 



1. Composite 53 149 



2. Gramineae 43 no 



3. Cyperaceas 10 108 



4 4. Leguminosae 24 57 



5. Rosacea; ; 15 46 



6. Labiatas 23 42 



7. Cruciferae 16 23 



8. Scrophulariaceae 15 32 



9. Filices 16 30 



10. Ranunculaceae 7 27 



11. Ericacea? n 26 



12. Cupuliferas 7' 26 



13. Orchidacere 12 24 



14. Liliacea? 18 24 



15. Polygonacese 3 23 



16. Umbelliferae 17 22 



The whole number of systematic orders represented in our Dis- 

 trict is 116, of which sixteen, or 14 per cent, furnish 55 per cent, 

 of the genera and 62 per cent, of the species. 



