23 



phytoplankton and the sediments in littoral waters. Univ. of New 

 Hampshire, Water Resource Research Center Res. Rep. No. 35. 

 101 pp. 



Love, A. and D. Love. 1938. The American element in the flora of the 

 British Isles. Bot. Not. 3: 373-388. 



Love, A. and D. Love. 1961. Some notes on Myriophyllum spicatum. 

 Rhodora 63: 139-145. 



Manuel, C. Y. 1973. Morphological variation in Myriophyllum heter- 

 ophyllum. Master's thesis, Washington University, St. Louis. 



Morong, T. 1891. Notes on North American Haloragaceae. Bull. Tor- 

 rey Bot. Club 18: 229-246. 



Morong, T. 1891a. Myriophyllum farwellii. Bull. Torrey Bot. Club 18: 

 146-147. 



Nichols, S. A. 1975. Identification and management of Eurasian 

 watermilfoil in Wisconsin. Wise. Acad. Arts 63: 116-128. 



Patten, B. C. 1954. The status of some American species of Myriophyl- 

 lum as revealed by the discovery of intergrade material between 

 M. exalbescens Fern, and M. spicatum L. in New Jersey. Rhodora 

 56: 213-225. 



Reed, C. F. 1977. History and distribution of Eurasian watermilfoil in 

 United States and Canada. Phytologia 36: 417-436. 



Schmidt, G. L. and W. F. Millington. 1968. Regulation of leaf shape in 

 Proserpinaca palustris. Bull. Torrey Bot. Club 95: 264-286. 



Wallenstein, A. and L. S. Albert. 1963. Plant morphology: its control in 

 Proserpinaca by photoperiod, temperature and gibberellic acid. 

 Science 140: 998-500. 



HIPPURIDACEAE 



Hippuris (Mare*s-tail) 



Emersed or submersed perennial; growing firom rhizomes; leaves 

 whorled, entire, linear-attenuate; flowers sessile, perfect or polygam- 

 ous, axillary in middle and upper leaves; fruit a small, ovoid nut. 



1. Hippuris vulgaris L. Fig. 7, Map 13 



Locally abundant along damp shores or in shallow waters of 

 northern Maine, uncommon in New Hampshire and Vermont. Range 

 extends from Greenland west to Alaska south to Newfoundland, 

 Nova Scotia, northern New England, central New York, Indiana, 

 northern Illinois, Minnesota, Nebraska, and New Mexico. 



