19 



extends from Massachusetts and Rhode Island south to southern New 

 Jersey. CaroHna plants called S. teres by Beal (1960) are identified by 

 Godfrey and Adams (1964) as S. isoetiformis. 



Rare and endangered plant lists: Massachusetts, New England 



alkalinity: mean 5.5 mg/1; range 4.0-7.0 mg/1 

 pH: mean 5.2; range 4.5-5.9 



4. Sagittaria graminea Michx. Fig. 8, Map 9 



Common in freshwater ponds and lakes throughout New Eng- 

 land; uncommon in tidal waters. The taxon is more abundant in the 

 acid waters of eastern New England. Sagittaria graminea has a 

 number of recognized varieties in the United States, but only the 

 typical variety is found in New England. This treatment includes S. 

 eatonii J. G. Smith of tidal areas. A single'record of this species fruiting 

 in New England is known. This species of Sagittaria produces the 

 greatest number of sterile rosettes in our area. Range extends from 

 Newfoundland and southern Labrador west to Ontario and Minne- 

 sota, south to Florida, Illinois, Missouri, and Texas; Cuba. 



alkalinity: mean 18.7 mg/1; range 3.0-111.5 mg/1 

 pH: mean 7.0; range 6.4-8.4 



5. Sagittaria rigida Pursh Fig. 9, Map 10 



Common in the Champlain Valley of Vermont, widely scattered 

 and uncommon elsewhere in New England. The plant has a tendency 

 to be found in more alkaline waters; occasionally found in tidal waters. 

 The leaf blades are quite variable, ranging from slender lanceolate leaf 

 to broad oval leaf, and occasionally becoming somewhat sagittate 

 with the development of small basal lobes. A submerged form with 

 bladeless slender phyllodia is sometimes found. Range extends from 

 Quebec and Maine west to Ontario and Minnesota, south to Virginia, 

 Kentucky, Tennessee, Missouri, and Nebraska. 



alkalinity: mean 31.3 mg/1; range 10.0-57.5 mg/1 

 pH: mean 7.4; range 6.5-8.9 



6. Sagittaria latifolia Willd. Fig. 10, 11, Map 11 



Extremely common throughout New England in acid and alkaline 

 waters. The erect leaves are extremely variable, ranging from narrow 

 leaves without a blade to narrowly sagittate to broadly sagittate 

 leaves. Several dubious varieties and forms have been named based on 

 leaf shapes, but leaves delineating these names may all occur on the 

 same plant. It is the most common Sagittaria in New England and the 

 northeast. Range extends from New Brunswick west to British 



