772 INTRODUCTION. 



the region with the intention of publishing a report, until within the 

 last two years, it is reasonable to infer that many plants will yet be 

 found that are not included in this report. The author has corres- 

 ponded and held conferences with not only the botanists of the county, 

 but with those of New York city. 



The botanists of New York city are active, industrious collectors, 

 and have absolutely exhausted most of the localities within walking 

 distance of the city; especially such portions of New Jersey, Staten 

 Island and parts of Long Island. The Harlem River, however, seems 

 to have been, to a great extent, the limit to their excursions in this 

 direction; hence, this county is less known to New York botanists 

 than any other region within the same distance of the city. The 

 collecting of information has, therefore, been more formidable than 

 suspected. 



The State of New York has a remarkably large Flora ; but it has a 

 territory extending about 350 miles from north to south, and nearly the 

 same distance from east to west — giving it a wide range of climate and 

 temperature. It has plains along the coast elevated just a little above 

 the sea level, and mountains on the eastern border rising 6,000 feet 

 above the ocean ; it possesses every variety of soil, from the sands of 

 the Sarenac region to the alluvial plains of the western slope and the 

 rich bottom lands of the Head waters of the Susquehanna, and the val- 

 leys of the Mohawk and the Upper Hudson. 



Dr. Torrey, in his report of the Flora of the State, stated that the 

 number of flowering plants would reach 1,450 ; and the Ferns and 

 Lycopodiaceae. sixty. 



There will be great reason, then, for wonder, when it is found that the 

 number of plants growing without cultivation in Westchester County — 

 a territory about fifty miles in extent from north to south, and whose 

 average width from east to west is not half so much — is more than a 

 thousand. 



There are 1,142 flowering plants enumerated in this catalogue, and 

 forty-six ferns and their allies. 

 " The formation of the county is chiefly Gneisic and Limestone rocks. 

 Limestone is sprinkled throughout, but especially along the middle, 

 from north to south. The southern half is divided by two parallel val- 

 leys, which trend north and south — dipping towards the south — and 

 about three miles apart, separated by a ridge of hills. The valley on 

 the Eastern side of the ridge is drained by the Bronx River, and the 

 other (in part) by Saw-Mill River continued by Tibbitt's Brook. This 

 limited territory has no difference of climate and temperature. 



