TORREYA :^Z. 



Vol. 22 BOTaNK^iNo. 



January -February, 1922 gAAU'ttJ*. 



LOCAL FLORA NOTES— ST ATEN ISLAND* 



By Arthur Hollick 



Staten Island, or the Borough of Richmond of Greater New 

 York, has been so thoroughly explored that recorded additions 

 to its flora in recent years have been very few; and the growth 

 of the community during the same time has probably resulted in 

 the total or partial extinction of as many native species as have 

 been added. On the other hand the advance of civilization has 

 brought with it a number of alien species, some of which ha\-e 

 become permanent elements in the local flora. In this connec- 

 tion two restricted areas have enlisted my interest and attracted 

 my special attention during a little longer than the past decade 

 One of these, on and in the vicinity of Todt Hill, is an area 

 that has undergone relatively little change in its natural en- 

 vironment for several generations other than its modifications 

 due to the development of the golf links of the Richmond County 

 Country Club. The other, in the vicinity of Arlington station 

 on the North Shore branch of the Rapid Transit Railroad, has 

 been completely changed from its natural conditions by commer- 

 cial developments. 



The Todt Hill area possesses geological as well as botanical 

 features of interest, and the two are closely interrelated. When 

 the continental glacier of the ice age reached Staten Island in 

 its advance from the northwest it was unable to surmount the 

 highest point immediately north of Todt Hill, and flowed around 

 its flanks to the east and west, leaving unglaciated a small 

 portion of the ridge of serpentinoid rock in the form of a con- 

 spicuous morainal embayment or sinus. This is the Todt Hill 

 area, and is the only area on the serpentinoid ridge in which the 

 sub-surface and most of the surface soil is composed of the dis- 

 integrated underlying rock. It is largely an undisturbed mag- 



* Presented at the meeting of the Torrey Botanical Club, October 26, 192 1. 



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