Major Plant Communities 
d 
Physiognomy. Tlie well-known xerophytic structure of seaside dune 
plants is observed here. 
Associations. In addition to the associations dominated by the type 
species, the following are often locally prominent: 
Spartina patens 
Oenothera humifusa 
Croton punctatus 
Successional Pelations. Physiographic changes may locally affect 
the formation but on the relatively stable dunes of the southeastward 
facing shore, the formation maintains itself throughout long periods 
of time so that we may here speak of this major community as a physio¬ 
graphic subclimax formation. Eventually, as indicated by the older 
dunes lying back from the sea, this formation is succeeded by the mari¬ 
time Quercus-Juniperus association of the Quercus-Acer-Pinus forma¬ 
tion. 
Fig. 1. Uniola-Cakile formation on Coastal dunes near Wilmington, N. C. 
2. Juncus-Spartina (Juncus roemerianus, Spartina stricta). Salt 
Marsh. 
Distribution. Along the salt-water sound shores and borders of 
brackish river mouths. 
Habitat. The salt marshes; substratum of dark silty material satu¬ 
rated with salt water. 
