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NAJADACEAE 



Najas (Naiad) 



Submersed annuals of fresh and sometimes saline water; 

 leaves sub-opposite or appearing whorled; serrate or spinulose 

 along the edges; fruit borne in the axils of the leaves; 

 submerged. 



Key to Species 



1. Leaf bases tapered (figs. 39B,C, 40D) . 



2. Leaves acute or rounded, not sharp-pointed (figs. 

 39B,C); style 0.5 mm or less in length (fig. 39D) ; 

 seed dull, with 15-18 rows of areolae (fig. 39E) . 

 N^ guadalupensis 



2. Leaves tapered to a sharp point (fig. 40D) ; style 1.0 

 mm or more in length (fig. 40B) ; seed shiny, with 

 30-40 rows of areolae (fig. 40C) . 

 N_j^ flexilis 



1. Leaf bases lobed (Figs. 41B, 42B,C). 



3. Leaf blades, usually less than 0.3 mm wide (fig. 4lB) ; 

 leaf margins not conspicuously toothed to the unaided 

 eye (fig. 41B) ; fruit with approximately 24 rows of 

 areolae (fig. 41D) . 

 N^ gracillima 



3. Leaf blades 0.3-0.5 mm wide (figs. 42B,C); leaf 

 margins often conspicuously toothed to the unaided eye 

 (figs. 42B,C) ; fruit with 12-18 rows of areolae (fig. 

 42D) 

 N. minor 



1. Najas guadalupensis (Spreng.) Magnus Fig. 39, Map 39 



Rare but locally abundant in alkaline, acid or brackish 

 waters at eleven widely scattered localities in New England. 

 Range extends from southwestern Quebec and Maine west to 

 Michigan, South Dakota, Idaho, and Oregon, south throughout the 

 United States and Mexico. 



Rare and endangered plant lists: Massachusetts, Vermont 



alkalinity: mean 25.7 mg/1; range 19.5-41.5 mg/1 



pH: mean 7.4; range 7.2-7.5 



chloride: mean 413.5 mg/1; range 10.9-1201.2 mg/1 



2. Najas flexilis (Willd.) Rostk. and Schmidt Fig. 40, Map 40 



Extremely common throughout New England. Range extends 

 from Newfoundland west to Minnesota, Alberta and British 



