A GUIDE AND KEY TO AQUATIC PLANTS 117 



5. A^. Jlumatile (Harper) Standley — Coastal Plain, West Florida 

 to Alabama and North Carolina. Usually occurs in connection with 

 streams or rivers, but may be found in perfectly still water. 



6. A^. chartaceum (Miller & Standley) Standley — Ponds near the 

 Gulf from Florida to Mississippi. 



7. N. advena Ait. Cow-lily — Most widely distributed and most 

 frequent species of the genus. Range covers all of our States and is 

 often found in alluvial situations. Nymphaea macrophylla Small 

 is included in this consideration of A^. advena. 



2. Nymphaea L. 



1. Flowers white 1. N. odorata. 



1. Flowers blue or yellow 2. 



2. Flowers blue 2. N. elegans. 



2. Flowers yellow 3. N.flava. 



1. A^. odorata Ait. White Water-lily — Distributed over all of our 

 territoiy and very frequent. Shows an extremely wide acidity 

 tolerance, being found in tlie most acid and the most alkaline waters 

 alike. This and the two following species are listed under Castalia 

 by Small's Manual. 



2. N. elegans Hook. Blue Water-lily — Big Cypress Swamp, 

 Florida, but may be introduced at other pdLnts. 



3. N. jlava Leitner. Yellow Water-lily — Known only from lakes, 

 ponds, and slow streams on the peninsula of Florida. 



3. Cabomba Aubl. 



C. caroliniana A. Gray. Fanwort — Mat-forming species, distrib- 

 uted over most of our territory, but not frequent in most portions. 

 Perhaps most often found in alluvial aquatic areas. 



4. Brasenia Schreb. 



B. schreberi Gmel. Water-shield — Well distributed in a variety 

 of aquatic situations, its range covering all of our territory. Col- 

 lected from alluvial marshes and swamps, as well as from very acid 

 limesink ponds. Some investigators have found a negative correla- 

 tion with Anopheles quadrimaculatus. 



5. Nelumbo Adams. 



A^. lutea (Willd.) Pers. Lotus, Water-chinquapin — Well distributed 

 over the Coastal Plain, collected or noted in a variety of situations by 

 the writers. Grows in acid limesinks, alluvial marshes, and other 

 aquatic areas where it is not indigenous (for instance, borrow pits and 

 artesian impoundments). In the Tennessee Valley it is often found 



