73 



(1. Lemna.) 



perpusilla? Torrey. 



Ditches; Cherry Island, near H. Latimer's. Not 

 very common, 

 polyrhiza, L. 



Ditches; New Castle road. Common. 



Order 95.— NAIADACE^E. 115. 



1. Naias, L. (Caulinia, Wttld.) 



flexilis, Rostk. 



Ponds and slow streams. Common. July. 



2. Zannichellia, Mcheli. 



palustris, L. (Horned Pondweed.) 



Ponds and slow streams; ditches near Port Penn. 

 Frequent. Hare elsewhere. June, 



3. POTAMOGETON, Toum. 



hybridus, Miclix. 



Ponds and ditches; Andrews', J. Brown's. Fre- 

 quent. July, 

 pauciflorus, Pursh. 



Slow streams; Brandy wine, &c. Common. May. 

 perfoliatus, L. 



Similar places. Frequent. Aug. 

 crispus, L. 



Ditches; Cherry Island. May. Common. Abundant 

 throughout the lower part of the county. Speci- 

 mens sent to Dr. Gray were identified by him. 

 prseldngus, Wulf. 



Ponds and streams; St. George's (Dr. Michener). 

 lucenSj L. 



Ditches, near "Wilmington (Dr. Michener). Aug. 

 fluitans, Roth. 



Ditches; Cherry Island and elsewhere. Common. 

 Aug. 

 nutans, L. (Snakeweed.) 



Slow streams; Brandywine races. Very common. 

 July. 

 heterophyllus, Schr. 



Shallow streams; Brandywine. Frequent. July. 

 6 



