ym PREFACE. 



almost every year, to the Flora of that country. So in the immediate vicinity of New- 

 York, which has probably been more diligently searched than any other region of the same 

 extent in the United States, frequent accessions are made to our list of species, and doubt- 

 less many others remain to be detected. A considerable number of plants are extremely 

 local ; others disappear, or become extremely scarce for a number of seasons ; and some 

 wither away shortly after perfecting their flowers and fruit, so that many species may for 

 a long time escape detection. The parts of the State that have been least explored botani- 

 cally are the counties which lie on the borders of Pennsylvania, and the region which has 

 been appropriately called the northern wilderness, included in our Fourth District. Portions 

 of Long Island, also, are far from being exhausted. At the end of the work will be found 

 a list of such plants as we expect will be added to our Flora by future observers, with the 

 parts of the State where they will probably be found. 



It is with pleasure that I make acknowledgments to the numerous botanical friends who 

 have kindly assisted me by contributing specimens of plants, or information, for this work. 

 The most efiicient aid has been rendered by Peter D. Knieskern, M. D., late of Oriskany ; 

 Prof. A. Gray, now of Harvard University ; H. P. Sartwell, M. D. of Penn Yan ; and 

 J. Carey, Esq. of New- York ; especially in exploring the western and some of the northern 

 counties. I am also indebted to Mr. Carey for much judicious criticism respecting many 

 obscure plants. Professors Emmons and Hall, of the Geological Department of the 

 Survey, supplied me with some rare plants from their respective districts. Dr. Bradley, 

 of Greece, gave me valuable information respecting the botany of Monroe and Oneida 

 counties. From Professor C. Dewey, I have received friendly assistance in obtaining a 

 knowledge of the plants around Rochester. He has also supplied me with authentic 

 specimens of many species of Carex, described by him in Silliman's Journal. Mr. George 

 Vasey, of Oriskany, has sent me some rare plants of Oneida County and other parts of the 

 State. Matthew Stevenson, M. D., kindly allowed me to select what I wished from his 

 herbarium, and in former years freely gave me the results of his numerous herborizations 

 in Washington county, where he resided a long time. To John Wright, M. D., of Troy, 

 I am indebted for plants collected in the neighborhood of that city ; and to Allen Wass, 

 M. D., for a list of the plants of Stephentown, Rensselaer County, with their times of 

 flowering and fructification. Edward Tuckerman, Esq., and Jonathan Pearson, M. D., 

 gave me information respecting several rare plants which they found in the neighborhood 

 of Schenectady. Charles Benner, Esq., has given me the results of his botanical excur- 

 sions among the Catskill Mountains. To Prof. Bailey, of West Point, I am under many 

 obligations for remarks on plants of the Highlands, as well as for specimens, besides assis- 

 tance in some difiicult microscopical investigations. Mr. M. B. Halsted, a zealous young 

 botanist of Newburgh, communicated to me many rare plants of Orange County. Mr. O. 

 R. Willis, and Prof. F. C. Schaffer, have supplied me with specimens illustrating the 

 botany of Long Island. Dr. S. B. Mead, now of Illinois, has kindly sent me remarks on 

 some rare plants collected by him in Westchester County. In exploring the vicinity of 

 New-York, much assistance has been given to me by J. Carey, Esq., and Mr. R. J. 



