PREFACE. 



The indulgent reception given to my Catalogue of the Phcenoga- 

 mous plants growing in the vicinity of the Borough of West-Ches- 

 ter, very naturally encouraged me to attempt a more complete Flora 

 of the whole County. The industry and kindness of botanical 

 friends, in exploring different sections of the County, and furnishing 

 me with their collections, aided me greatly in the attempt ; and I now 

 submit to the lovers of botanical pursuits the result, such as it is, of 

 my investigations. 



There are many and obvious reasons why a work like this — prose- 

 cuted in the seclusion of a village residence — should be imperfect, and 

 behind the improvements of the age: yet I feel that I have abundant 

 cause to be grateful for the liberal and friendly assistance afforded me, 

 whenever practicable, by a number of distinguished Botanists. 



It may be in some measure perceived, by the annunciations in the 

 course of the work, how numerous are my obligations, for specimens, 

 and a knowledge of localities, to my friends in the County ; and I 

 gladly embrace this occasion to reiterate my acknowledgments for 

 their kind attentions, and for the interest they have been pleased to 

 manifest in the undertak ; ng. 



To Dr. Chvrles Pickering, of Philadelphia, I am most especially 

 and deeply indebted, for the obliging promptitude and patience with 

 which he aided me in my references to the valuable Herbariums under 

 his charge, in that city ; and my thanks are also due to the venerable 

 Librarian of the Philosophical Society, for the facilities afforded in 

 consulting the Muhlenberg' an Herbarium, in possession of that Insti- 

 tution. 



Since the return of Mr. Nuttall, from his Western expedition, I 

 have had the benefit of his opinions, and suggestions, in relation to a 

 number of our more difficult plants. 



With Prof. Tourist, of New York, I have enjoyed the privilege of a 

 botanical correspondence for some twelve years past ; and those who 

 are acquainted with the eminent attainments of that gentleman will not 

 need to be told, that it must be my own fault if I have not profited 

 largely by the intercourse. His judicious remarks, and his frank and 

 liberal communications, have ever been to me a source of agreeable in- 

 terest and instruction. 



To the kindness of Dr. A. Gn at, of the same city, I am also indebt- 

 ed for the use of several important works which at the time were not 

 elsewhere to be obtained, in the U. States. 



From my estimable Correspondents, Prof. C. W. Short, of Ken- 

 tucky, and the Rev. M. A. Curtis, of North Carolina, I have received 

 numerous specimens of Western and Southern plants, which have been 

 exceedingly useful, on comparison, in enabling me to determine some 

 of our doubtful species. 



