- 26 - 



Rare and endangered plant list: New Hampshire, although 

 frequent along the Connecticut River. 



alkalinity: mean 50.9 mg/1; range 4.5-123.5 

 pH: mean 7.5; range 5.8-10.2 



11. Potamogeton hillii Morong Fig. 13, Map 13 



Uncommon in highly alkaline ponds and streams of western 

 New England with the exception of being locally abundant at 

 numerous locations in Berkshire County, Massachusetts. Prior to 

 1972 this species was known only from five locations in New 

 England. Extensive field work has shown it to be more abundant. 

 Range extends from Vermont to northwestern Connecticut, west to 

 southern Ontario, northern Michigan, south to Pennsylvania, New 

 York, and eastern Ohio; most abundant in western New England, 

 eastern New York and northern Michigan. 



Rare and endangered plant list: Vermont, Massachusetts 



alkalinity: mean 141.5 mg/1; range 86.0-290.0 mg/1 

 pH: mean 7.5; range 7.2-8.2 



12. Potamogeton foliosus Raf. Fig. 14, Map 14 



Common in alkaline waters of northeastern Maine, 

 Vermont, western Massachusetts and Connecticut; scattered 

 elsewhere. The treatment of this species follows that of Haynes 

 (1974) which does not recognize the narrow-leaved variety 

 macellus as distinct. In New England this species is 

 predominantly narrow-leaved. Range extends throughout North 

 America from Nova Scotia west to central Alaska, south to 

 Jamaica and Guatamala; most abundant in northeastern United 

 States and the Great Lakes States. 



alkalinity: mean 73.5 mg/1; range 14.0-290.0 mg/1 

 pH: mean 7.8; range 6.5-9.8 



13. Potamogeton f riesii Rupr . Fig. 15, Map 15 



Uncommon to rare in alkaline waters of Aroostook County, 

 Maine and western New England. The single eastern Massachusetts 

 population has long been extinct. Range extends from western 

 Newfoundland and Labrador west to central Alaska, south to 

 Pennsylvania, western Nebraska, and Utah; most abundant in the 

 Great Lakes region. 



Rare and endangered plant lists: Massachusetts, Connecticut, 

 Vermont 



alkalinity: mean 71.2 mg/1; range 35.0-123.5 mg/1 

 ph: mean 8.0; range 7.0-9.8 



14. Potamogeton str ictifolius Benn. Fig. 16, Map 16 



Uncommon in alkaline waters of Aroostook County, Maine 

 and numerous locations in western New England. The treatment of 



