FLOWERING PLANTS. 41) 



2. L. minor. Lesser Duckweed. 5-8. 

 Swamps near Willington Bridge. 



3. L. ijihha. Gibbons Duckweed. 6-9. 

 Common. 



4. L. pohjrrhka. Greater Duckweed. 

 Common. 



ORDER LXXVIII.— NAIADES. 



III.— ZANNICHELLIA. 

 1. Z. palustris. Horned Pondweed. 



V.-POTOMAGETON. 

 1. P. natans. Broad Pondweed. 6-8. 

 Old Trent and the Millstream. 



3. P. lucens. Shining Pondweed. 6-8. 

 Old Trent. 



5. P. perfoliatus. Perfoliate Pondweed, 6-8. 

 Millstream. 



6. P. crispiis. Curly Pondweed. 6-7. 

 Millstream. 



7. P. densus. Opposite Pondweed. 7-8. 

 Old Trent. 



9. P. pectinatus. Fennel Pondweed. 7-8. 



ORDER LXXIX.— ALISMACEiE. 



I.— BUTOMUS. 

 1. B. umbellatus. Flowering Rush. 6-7. 

 New Trent, by Bathing-place. 

 5 



