105 



Potamogeton. Oakesianus, Bobbins. 



Foster's pond, Beverly, 1873 (J. E.) ; Sluice pond, Lynn (Edwin 



Faxon). 

 Potamogeton Claytonil, Tuckerman. 



Ponds and brooks. Common. 

 Potamogeton Spirillus, Tuckerman. 



Old mill brook, Boxford ; Merrimac river at Lawrence, Georgetown. 



There Is a variety, with no floating leaves, in Chebacco pond. 

 Potamogeton hybrldus, Mickz. 



Common in stagnant water. 

 Potamogeton loncMtes, Tuckerman. 



Ipswich river. Merrimac river at Lawrence. 

 Potamogeton pnlcher, Tuckei-man. 



Chebacco pond ; Ipswich river ; Beaver pond, Beverly ; Crane pond, 



West Newbury. 

 Potamogeton amplifolius, Tuckerman. 



Wenhara pond, Ipswich river, ponds in Andover and Haverhill ; fine 



fruit Aug. 19 (1879'), Crane pond, West Newbury, river Parker, etc. 

 Potamogeton gramineus, L. 



Wenham, and Pleasant ponds, Wenham. Quite abundant and vari- 

 able. 

 Var. heterophyllus. Fries. 



Georgetown (J. H. Sears), Sluice pond (C. E. Faxon). 

 Potamogeton lucens, L. 



" Breed's pond, Lynn" (Tracy). Recent search has failed to verify 



this determination ; and specimens, which at first were supposed to 



be this species, proved to be imperfectly developed forms of P. 



amplifolius. 

 Var. minor, Nolte. 



Pleasant pond, Wenham (J. R., etc.). Scarce. This will probably 



prove a good species, and as it is the same as the European P. 



Zizii, M. & K., it will be given under that name. 

 Potamogeton prselongus, Wulfen. 



Wenham and Pleasant ponds, Wenham. 

 Potamogeton perfollatus, L. 



Ponds and streams. Frequent. 

 Potamogeton zosterssfolius, Schumacher, Potamogeton com- 



pressus, L. (Gray's Manual). 



River Parker, West Newbury (J. R.) ; Lynnfleld (Edwin Faxon). 



Rare. 

 Potamogeton obtusifollus, Mertens & Koch. 



Pleasant pond, Wenham, Aug., 1875 (J. R.), 1880 (C. E. Faxon). 

 Potamogeton pauciflorus, Pursh. 



Wenham pond; Flax pond, Lynn (Tracy), Boxford. 



