Potamogeton POTAMOGETONACEAE Potamogeton 



POTAMOGETONACEAE (Pond weed Family) 



Potamogeton L. Pondweed. 

 P. natans L. 



Infrequent in ponds and slow streams. Frt. July to Sept. 



P. epihydrus Raf. var. Nuttallii Fernald. 



Frequent in streams and ponds of the Piedmont and Coastal 

 Plain. Frt. July to Sept. 



P. americanus C. &. S. (P. nodosus Poir. See Rhodora 45, 125. 

 1943.) 

 Frequent in streams, chiefly in the Piedmont. Frt. Aug., Sept. 



P. pulcher Tuckerman. 



In ponds and ditches; frequent north of the Virginia line. Frt. 

 late June, July. 



P. Richardsonii (Bennett) Rydb. {P. perfoliatus L. var. Richard- 

 sonii (Fieb.) Graebn.) 

 Infrequent; ponds and river shores, Cecil and Sussex Counties. 

 Frt. Aug., Sept. 



^ P. bupleuroides Fernald. (P. perfoliatus var. bupleuroides (Fer- 

 nald) Farwell.) 

 Infrequent; in fresh and brackish streams, chiefly of the Coastal 

 Plain. Frt. July to Sept. 



P. crispus L. 



Infrequent; in Brandy wine and Red Clay Creeks (NC); the last 

 known collection made in 1880. 



P. Berchtoldi Fieber var. colpophilus (Fernald) Fernald. (P. 

 pusillus L. var. colpophilus Fernald. See Rhodora 42, 

 246. 1940.) 

 Rare: Snow Hill (Wo), Shreve & Jones, 1087 (U). 



Var. tenuissimus (Mertens & Koch) Fernald. 



Rare: Drummonds Pond, s. w. of Parksley (Ac), R. R. Tat- 

 nall, 2654, 3 June 1935 (T) ; "Newark road under Del. R. R.," 

 E. Tatnallm. 1896 (D). 



Var. lacunatus (Hagstrom) Fernald. 



Rare: stagnant pool along Big Elk Creek (Ce), Pennell, 26 

 July 1913 (A). 



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