1902] Rich, — Oak Island and its Flora 93 



the entrance and flourished for several years. Now nearly 

 obliterated. 

 Of the foregoing 54 species and varieties 40 are additions to 



Young's List. The remaining 14 representing changes and segrega- 

 tions made since that date. 



There have also been some subtractions from the flora of the 



island, the following plants and perhaps a few others not having 



been seen by the writer in recent years. 



Orchis spectabilis, L. Probably exterminated by visitors digging up 

 the plants for transplanting into gardens. 



Cnicus horridulus, Pursh. (Cirsium horridulum L.). As this 

 species grows abundantly but a short distance away on the 

 Saugus marshes its reappearance on the Oak Island borders 

 may be confidently predicted. 



Gentiana Andrewsii, Griseb. Not found since. 



Arabis pcrfoliata, Lam. Not found since. 



Phragtnites communis, Trin. Voung notes "three specimens in the 

 northwestern part." Here is an instance of extermination 

 from natural causes. It is a well-established fact that the 

 coast of New England has undergone a gradual subsidence 

 at the rate of about eighteen inches in a century. On the 

 Nahant shore opposite Oak Island stumps of forest trees 

 can still be seen just below the low-water line and on the 

 Revere Beach shore the writer is informed by Mr. John H. 

 Sears, the eminent geologist of Essex County, that masses of 

 the roots of Phragmites, cat-tail flag, cow lily, as well as the 

 remains of numerous forest trees, such as beech, white pine, 

 oak, spruce, hemlock and hop-hornbeam have been found 

 imbedded under the waters of the bay. No other locality for 

 the Phragmites is known within a dozen miles and it is 

 evident that the specimens seen at Oak Island by Mr. Young 

 in 1882 were the last remnants of this giant grass that in 

 former times waved its great plumes in solid phalanx in this 

 vicinity. 



Epiphegus Vtrginiana, Part. The disappearance of this plant may be 

 attributed to the same cause. 

 Some species noted in the List as scarce or seen only in a few 



specimens have greatly increased since that time. Among such are 



Lecrsia Virginia!, Willd., Verbena hastata, L., Pedicularis Canadensis, 



