A GUIDE AND KEY TO AQUATIC PLANTS 119 



MAGNOLIACEAE Magnolia family 



1. Magnolia L. 



M. virginiajia L. — This tree (sometimes shrub) is found over all of 

 our Coastal Plain and seems to prefer acid soils. 



CRUCIFERAE Mustard family 



1. Rorippa Scop. 



R. sessilijiora (Nutt.) Hitchc. Water-cress — Various provinces, 

 Florida north and west to beyond the limits of om* territory. The 

 senior writer has collected it from ponds in the Mississippi Valley in 

 Tennessee and Mississippi. This species is listed under Radicula by 

 Small. 



2. Neobeckia Greene 



A^. aquatica (A. Eaton) Britton. Lake-cress — Said to range over 

 most of our territory but noted by the WTiters only in the western 

 portion. 



3. Nasturtium R. Brown 



N. officinale R. Brown. Water-cress — Very variable species, rang- 

 ing over all of our territory from Georgia north and west, particularly 

 in springy places. Tliis species is called Sisymbrium Nasturtium- 

 Aquaticum L. by Small. 



CRASSULACEAE Orpine family 

 1. Penthorum [Gronov.] L. 



P. sedoides L. Ditch Stonecrop — Swamps and ponds usually in 

 association with streams, over all of our territory. 



ITEACEAE Virginia willow family 



1. Itea [Gronov.] L. 



/. mrginica L. Virginia Willow — Ranges over most of our Coastal 

 Plain and is occasionally foimd in the Piedmont, most often in asso- 

 ciation with creeks or small streams. 



ROSACEAE Rose famUy 

 1. Rosa [Tourn.] L. 



R. palustris Marsh. Swamp Rose^ — Swamps and ponds over ahnost 

 all of our territory. 



