ALTAMAHA GRIT REGION OF GEORGIA 75 



find any one species in more than two of these habitats, though 

 some genera {Pinus for instance) are represented in all of them. 



This particular sequence cannot be carried farther in the same 

 direction, so we will now consider a series of habitats which are 

 not so closely related to the preceding, namely, the ponds. These 

 are principally of three kinds, cypress ponds, shallower ponds, 

 and deeper ponds. 



9. Cypress Ponds. 



These ponds, (plate X, fig. 1.) characterized always by a 

 rather dense growth of pond-cypress. Taxodium imbricarium, 

 occur in most of the counties, but are rather scarce in the 

 northernmost ones. They are simply shallow depressions in 

 the otherwise nearly level pine-barrens, varying perhaps from 

 one to a hundred acres in extent. (What originally caused these 

 depressions I cannot say.) In wet weather they may contain 

 two or three feet of water, but they dry up frequently enough 

 to prevent floating aquatics like the Nymphaeacese, Potamogetons, 

 and some Utricularias, from establishing themselves. The 

 cypress by reason of its erect branchlets and minute appressed 

 leaves (quite different from those of its swamp-loving congener) 

 gives little shade, and the cypress ponds are almost as sunny as 

 the adjacent pine-barrens. The bottoms of these ponds are 

 covered by a very thin layer of humus. The frequent desicca- 

 tion and sunning to which they are subjected doubtless limits 

 the accumulation of humus, as in the pine-barrens. The 

 Columbia sand seems to be always present in these ponds, as in 

 every other place where Taxodium imbricarium grows. 



The following are the characteristic species of cypress ponds. 



15 Taxodium imbricarium 2-3 — 



11 Pinus Elliottii 2 — 



2 Nyssa biflora 

 1 Ilex myrtifolia 

 6 Ilex myrtifolia 



6 Hypericum myrtifolium 6-9 yellow 



3 fasciculatum 4-8 yellow 



2 Pieris nitida 3-4 white 



1 Stillingia aquatica 4-7 yellow 



1 Malapoenna geniculata 

 1 Pieris phillyreifolia 2 white 



