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on which the flora is practically all native. This is pretty good 
evidence that such areas have not only never been artificially 
deforested, but also never been touched by the plow. Where 
the sod is once broken a very different flora, consisting largely 
of European weeds, comes in, so that areas which have ever been 
cultivated can be distinguished at a glance. The same is true 
to some extent of areas that have been too closely grazed. 
The prairie occupies the central portion of Nassau County, 
about midway between the north and south shores of the island. 
Like the pine-barrens of Suffolk County, a few miles farther 
Fic. 2. Looking westward across the dry valley of Hempstead Brook toward 
ае City, Myrica carolinensis at edge of valley іп right foreground. Sept. 
29, 1909 
east,* it lies entirely south of the latest terminal moraine (the 
Harbor Hill moraine), but partly overlaps or dovetails into the 
older of the two Long Island moraines (the Ronkonkoma mo- 
raine). Originally it extended westward to where Floral Park 
now is, and eastward to Central Park, a distance of about twelve 
miles, and had its greatest breadth from north to south, about 
seven miles, very near its eastern end. North of the straight 
main line of railroad from Floral Park to Hicksville, and also 
* See TORREYA 8: 2. 1008. 
