PREFACE. 



In 1830 was printed in Washington Flora Columbince. Prodro- 

 mes, a catalogue of all the plants hitherto collected in the District. 



It was compiled by John A. Brereton, M. D., U. S. A., and was a 

 record of the diligent and successful explorations of the " Botanic 

 Club," consisting of Wm. Mechlin, Wm. Rich, Alex. Mc Williams, 

 M. D., Jas. W. Robbins, M. D., and the compiler, during the five 

 years preceeding. That catalogue is now out of print. 



It was, therefore, two years ago, voted by the "Potomac-Side 

 Naturalists' Club," the lineal descendent of the older organization, 

 that Dr. Geo. Vasey, Prof. J. W. Chickering, Dr. E. Foreman, Prof. 

 Wm. H. Seaman, and Mr. L. F. Ward be appointed a cummittee to 

 prepare a new catalogue of the Flora of the District. 



This present catalogue is the record of the botanical explorations of 

 the club, during the past three or four years. 



Doubtless many additions will be made in the future, but it has been 

 judged best, as a means of giving definiteness to further exploration, as 

 of facilitating exchanges, to issue this catalogue at this time. 



Washington. D. C, 1876. — 6. — 1. 



