A GUIDE AND KEY TO AQUATIC PLANTS 139 



COMPOSITAE Composite family 



1. Sclerolepis Cass. 



S. unifiora (Walt.) B. S. P. — Pineland and cypress ponds, Coastal 

 Plain, Florida to Alabama* and north to beyond the limits of our 

 territory. 



2. Eupatorium L. 



1. Flowers purple 1. E. coelestinum. 



1. Flowers white 2. 



2. Leaf-blades narrowed at the base 3. 



2. Leaf-blades broadened at the base 2. E. rotundifolium. 



3. Bracts of the involucre acute or acuminate; leaves re- 3. E. leucolepis. 



motely toothed or nearly entire. 



3. Bracts of the involucre obtusish; leaves sharply toothed_ 4. E. semiserratum. 



1. E. coelestinum L. Mist-flower — Includes all of our area. Marshes 

 and along pond margins often in alluvial situations. 



2. E. roiundifolium L. — The range of this species in all of its varie- 

 ties covers all of our area, but it is commonest on the Coastal Plain. 

 It is often non-aquatic but is occasionally found in swamps. As used 

 here E. roiundijolinm includes also E. verbena ejolium, E. puhesccns, 

 and E. scah^dum of Small's Manual 



3. E. leucolepis (DC.) T. & G.— Ranges over all of our Coastal 

 Plain in acid ponds or bogs. 



4. E. semiserratum DC. — Swamps and ponds in the Coastal Plain, 

 Florida north and west to beyond the limits of our territory. 



3. Mikania Wmd. 



M. scandens (L.) Willd. Hemp-weed — Swamps, mostly alluvial, 

 over all of our territory. 



4. Pluchea Cass. 



1. Plants perennial 2. 



1. Plants annual 3. 



2. Outer bracts of involucre acuminate.* 1. P. foetida. 



2. Outer bracts of involucre obtuse or merely acute. 2. P. imbncata. 



3. Leaves not decurrent on stem making it winged 3. P. petiolata. 



3. Leaves decurrent on stem making it winged 4. P. quitoc. 



1. P.joetida (L.) DC. — Ponds, mostly in the Coastal Plain, Florida 

 north and west to beyond the limits of our territory. 



2. P. imbricata (Kearney) Nash — Swamps and ponds. Coastal 

 Plain, Florida to South Carolina. 



3. P. petiolata Cass. — Most often found in alluvial situations, its 

 range covering all of our territory. 



4. P. quitoc DC. — Naturalized species, known in this country from 

 marshy places in West Florida. 



