13 



3. Petiole terete, not winged (fig. 5D); leaves mostly erect, elevated 

 above the water surface (fig. 5C); inner surface of sepals and fruit 

 green and/or yellow. 

 4. N. advena 



1. Nuphar pumila (Timm) DC. Figs. 5, 7, Map 6 



Widely scattered in quiet waters of northern portions of Maine, 

 New Hampshire, and Vermont; rare elsewhere in New England. This 

 species once occurred more frequently throughout the region, but 

 recent attempts to relocate it in southern New England have been 

 unsuccessful. This taxon has long been treated as N. microphyllum 

 (Pers.) Fern. More recently Beal (1956) has treated this as N lutea 

 subsp. pumila (Timm) Beal which also occurs in northern Europe. 

 Range extends from Newfoundland west to Manitoba, south to Nova 

 Scotia, northern Michigan, northern Wisconsin, and northeastern 

 Minnesota. 

 Rare and endangered plant list: Maine 



alkalinity: mean 36.1 mg/1; range 3.5-103.5 mg/1; (9) 



pH: mean 7.4; range 6.5-9.5; (8) 



2. Nuphar Xrubrodisca Morong Figs. 5, 7, Map 7 



Widely scattered in quiet waters throughout New England, but 

 especially common in the Lake Champlain Valley of Vermont. This 

 taxon is believed to be a fertile hybrid between N pumila and 

 N. variegata. The stigmatic disc of the flower and fruit is usually 

 bright red. Young plants of N. variegata may be mistaken for N. 

 Xrubrodisca. Range extends from Newfoundland west to eastern On- 

 tario, south to Nova Scotia, Connecticut, New Jersey, eastern 

 Pennsylvania, New York, northern Michigan, northern Wisconsin, 

 and eastern Minnesota. 

 Rare and endangered plant list: Vermont 



alkalinity: mean 31.3 mg/1; range 3.5-57.5 mg/1; (8) 

 pH: mean 7.4; 6.7-8.2; (8) 



3. Nuphar variegata Durand Figs. 6, 7, Map 8 



Extremely common in slow moving waters throughout New En- 

 gland. This is one of the most common aquatic species in the region. 

 Beal (1956) treated this taxon as N lutea subsp. variegata (Durand) 

 Beal. Range extends from Newfoundland and Labrador west to 

 Yukon, south to Delaware, northeastern Pennsylvania, northern 

 Ohio, northern Indiana, northern Illinois, South Dakota, Nebraska, 

 and Montana. 



alkalinity: mean 27.7 mg/1; range 2.0-132.5 mg/1; (186) 



pH: mean 7.0; range 5.0-9.8; (181) 



