15 



Rare and endangered plant list: New Hampshire 



alkalinity: 15.0 mg/1 

 pH: 6.8 



5. Sparganium americanum Nutt. Fig. 7, Map 8 



Extremely common throughout New England. Erect (rarely float- 

 ing) plant of shallow water and damp shores. Floating plants, when 

 encountered, usually found in close proximity to erect plants along the 

 shore. Beal (1960) has reported that inflorescence branching and 

 supra-axillary pistillate heads are not infrequent in populations of the 

 Coastal Plain of the Carolinas. We have not observed this in plants of 

 this species in New England. Beal (1960) also notes that the characters 

 by which Clausen (1937) recognized his somewhat robust var. rigidum 

 occur scattered throughout the range of th.e species and the taxon is not 

 worthy of recognition. Range extends from Newfoundland west to 

 Ontario, Wisconsin, Minnesota and North Dakota, south to Florida, 

 Alabama, Oklahoma, and Texas. 



alkalinity: mean 17.7 mg/1; range 0.5-123.5 mg/1 

 pH: mean 6.9; range 5.3-9.8 



6. Sparganium angustifolium Michx. Fig. 8, Map 9 



Abundant in northern New England, widely scattered in southern 

 New England. Plants floating, with leaves 1.5-5 mm wide, often grow- 

 ing in deep water or occasionally slightly erect in shallow water. The 

 few plants from New England previously identified as Sparganium 

 multipedunculatum (Morong) Rydb. are included here since these 

 specimens differ from typical S. angustifolium only in a leaf width up 

 to 6.0 mm wide. All specimens seen were clearly floating in habit, not 

 erect, as is often characteristic for S. multipedunculatum. Sparganium 

 multipedunculatum . which is treated by some authors (Reveal, 1970) 

 as a variety of S. emersum Rehman {-S. simplex Hud.) typically has 

 larger fruiting heads (2.0-3.0 cm in diameter) and longer fruit beaks 

 (3.0-4.0 mm). Therefore, we no longer regard S. multipedunculatum as 

 occurring in the New England region. Range extends from Greenland, 

 Newfoundland, and Labrador west to Alaska, south to northern New 

 Jersey, northern Pennsylvania, Michigan, northern Illinois, Minne- 

 sota, Colorado, Utah, northern New Mexico, northern Arizona, and 

 California. 



alkalinity: mean 26.1 mg/1; range 2.5-103.5 mg/1 

 pH: mean 7.2; range 6.5-9.5 



