774 INTRODUCTION. 



By including hardy trees and shrubs which have been introduced, and 

 are growing in planted grounds, the list would be very much enlarged- 



EXPLANATIONS. 



The arrangement of this catalogne corresponds with that of the 

 latest edition of Gray's Manual of the Northern United States, and 

 the orders are numbered to agree with the numbers of the same orders 

 in the Manual. 



The words " Nat. Eu." mean the same as they do in the Manual, viz : 

 that the plants after whose names they appear, have been introduced 

 from Europe and are growing and propagating themselves freely without 

 cultivation, and are fully established. " Adv. Eu." indicate that plants 

 after whose names they are written, are from Europe ; that they are 

 growing without cultivation, but are not propagating themselves Avith 

 such freedom and constancy as to be considered fully established 



AIDS AND SOURCES OF INFORMATION. 



In the collecting of the material for this report, I have received valu- 

 able information and assistance from the Botanists of the county and 

 New York city. One of the most valuable sources of information has 

 been the Bulletin of the Torrey Botanical Club. 



But my thanks are especially due to Prof. Alphonso Wood, Ph.D., of 

 West Farms, Prof. W. H. Leggett, editors of the Bulletin of the Torrey 

 Botanical Club, and Curator P. V. Le Roy. To Miss P. A. Mecabe of 

 Scarsdale, Mr. Chas. C. Hexama of New Castle, Dr. G. J. Fisher of 

 Sing Sing, and E. P. Bicknell of Yonkers. 



