A GUIDE AND KEY TO THE AQUATIC PLANTS 

 OF THE SOUTHEASTERN UNITED STATES 



INTRODUCTION 



The purpose of this compilation is to enable workers in the field, with 

 little knowledge of botany, to identify at least generically those fresh 

 water plants with which mosquito breeding is associated. It is hoped 

 that the keys and short notes with their accompanying illustrations will 

 obviate the use of the difficult and cumbersome manuals which are at 

 present the principal source of knowledge concerning the Southeastern 

 aquatic plants, and will enable the worker to make more accurate and 

 adequate evaluations of the area in which he is working. 



The area considered in this guide, which in the text is often referred 

 to as "our territory" or "our range," includes the States of Tennessee, 

 North and South Carolina, Mississippi, Alabama, Georgia, and Florida. 

 States adjacent to these may be assumed to have similar aquatic floras, 

 but the range was thus limited because the above States are those with 

 which the authors are best acquainted. On the frontispiece map the 

 primary physiogi'aphic regions of these States are shown in outline. 



A difficulty in preparing a list of the kind presented here is determin- 

 ing which plants to include. The principal criterion used has been the 

 possibility or likelihood of the plant's being associated with mosquito 

 breeding. Even this breaks down, for in times of very high waters dry 

 land plants like the common cocklebur may shelter larvae. Possibly 

 some of these plants, purposely omitted from the list, should have been 

 included, and undoubtedly there are unintentional omissions of plants 

 that can be found associated with mosquito production; but it is be- 

 lieved that on the whole the situations met within the Southeastern 

 States are covered. 



GLOSSARY 



In as large measure as possible the authors have utilized in the 

 keys parts of the aquatic plant most familiar to the general worker 

 and have used terminology not requiring a great knowledge of plant 

 morphology. But for the sake of exactness it was found necessary to 

 use some of the precise botanical terms. All of these, and some of 

 the better known designations, are included in the illustrated glossary 

 below. 



Note. — Work was done at the Office of Malaria Investigations, Memphis, Tenn. 



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