44 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



Potamogeton gemmiparus Robbins (producing buds). 



Rare. Union, shallow water of Mashapaug Pond (Bis- 

 sell). July — Aug. 



Potamogeton foliosus Raf. (leafy). 

 Potamogeton pauciiiorus Pursh. 



Rare or local. Ponds and slow streams : Voluntown (Har- 

 ger), Southington (Andrews & Bissell), Newtown (Eames), 

 New Milford (C. K. Averill), Sharon and Salisbury (Bis- 

 sell). July — Aug. 



Potamogeton hybridus Michx. (mongrel). 

 Potamogeton diversifolins Raf. 



Occasional. In ponds. July — Aug. 



The var. multi-denticulatus (Morong) Asch. & Graeb- 

 ner (with many fine teeth) has been found at Groton (T. 

 Morong), Griswold (Harger), Milford and Stratford 

 (Eames). 



Potamogeton dimorphus Raf. (of two forms). 

 Potamogeton Spirillus Tuckerm. 



Frequent. Ponds and streams. June — Aug. 

 Floating leaves often wanting. 



Potamogeton pectinatus L. (comb-like). 



Rare or local. Ponds, streams and ditches : Hartford (D. 

 C. Eaton), East Windsor and Salisbury (Bissell), Oxford 

 (Harger), Stratford, New Milford and Kent (Eames). July 

 — Sept. 



Potamogeton Robbinsii Oakes. 



Occasional or local. Ponds, ditches and slow streams. 

 July — Aug. 



This species very rarely forms fruit. 



RUPPIA L. Ditch Grass. 

 Ruppia maritima L. (of the sea-coast). 

 Ditch Grass. 



Frequent in shallow water of pools, creeks and ditches 

 about salt or brackish marshes along the coast. July — Oct. 



ZANNICHELLIA L. Horned Pondweed. 

 Zannichellia palustris L. (of marshes). 

 Horned Pondweed. 



