ACKNOWLEDGEMENTS 



We wish to thank Drs. Robert K. Godfrey and George B. Rossbach 

 for their helpful comments on the manuscript. We are also grateful to 

 the curators of the following herbaria for use of their collections: BRU, 

 CONN, CUW, GH, NHN, KIRI, MASS, MAINE, NASC, NCBS, 

 NHA, NEBC, VT, YU. A special thanks is extended to Pamela Bruns 

 Brayton who prepared the illustrations. Gratitude is expressed to the 

 University of Wisconsin Press for permission to use or redraw several 

 figures from Fassett's Manual of Aquatic Plants. 



This work is a result of research sponsored by the New Hampshire 

 Agricultural Experiment Station. The NHAES reserves the right to 

 reproduce, publish or otherwise use, and to authorize others to use, the 

 work for Government purposes notwithstanding notice of copyright. 



Copyright 1985 by the University of New Hampshire. No part of this work may be 

 reproduced in any manner without permission from the authors and the University of 

 New Hampshire. 



Programs of the New Hampshire Agricultural Experiment Station are open to all 

 persons without regard to race, color, national origin or sex. The University of New 

 Hampshire is an Affirmative Action 'Equal Opportunity Employer. 



