i 



354 BOTANICAL GAZETTE [may 



especially in Florida, has been investigated and reported by Harper 

 (6), whose descriptive classification of habitats and extensive lists 

 of peat-forming plants present a summary of the plant associations 

 of the various sorts of swamps, marshes, bogs, ponds, lakes, and 

 streams. 



The water of these pre-erosion depressions, with their (usually) 

 sandy basins, is characteristically dark-colored, appearing blackish 



matter 



or less acid reaction. 



Lakes, ponds, and streams 



The vegetation of the ponds and of the slowly moving waters of 

 the sluggish little streams is not decidedly different, differences 

 depending rather on the depth of water and on the amount of 

 movement. In shallow, permanent water the aquatics are arranged 

 in the usual zonation, from those submerged or floating to those 

 rooted in the muck or sand of the bottoms and to the amphibious 

 plants of the margins. 



Lists of aquatics for the ponds and lakes include among the 

 submerged and floating forms Potamogeton spp., Ceratophyl- 

 lum denier sum L., Myriophyllum heter o phyllum Michx., Lemna 

 valdiviana Philippi, Castalia odorata Woodv. and Wood (and the 

 variety C. odorata gigantea Fernald), Nymphaea advena Ait., 

 Brasenia Schreiberi GmeL, Nelumbo lutea Pers., Nymphoides aqua- 

 ticum Fernald, Utricularia inflata Walt., U. biflora Lam., and U. 

 purpurea Walt. 



In marginal zones, Panicum hemitomum Schult., P. condensum 

 Nash, Dalichium arundinaceum Britt., Eriocaulon decangidare L., 

 E. compressum Lam., Mayaca Aubleti Michx., and Bacopa caro- 

 liniana Robinson usually grow in shallow water ; while the common 

 strand plants are Fuirena squarrosa Michx., Hemicarpha micran- 

 tha Britt., Rkynchospora corniculata Gray, Syngonanthus flavidulus 

 Ruhland, Drosera brevifolia Pursh, Hypericum virginicum L., H. 

 gentianoides BSP., Hydrocotyle umbellata L., Bartonia spp., Diodia 

 virginiana L., D. tetragona Walt., Spermacoce parviflora Gray, 

 Houstonia angustifolia Michx., Lobelia gland Hlosa Walt., and 

 Pluchea foetida DC. The cypresses (Taxodium distichum Rich, or 









