8 
North Carolina Experiment Station 
This formation merges in many places into other formations; its 
boundaries locally are not usually very sharp. So prominently, how¬ 
ever, does it stand out over large areas, that it is believed best to give 
it formational rank. 
There can be little doubt that the xerophytism evinced in the Ilex- 
Myrica formation is homologous to the xerophytism of the northern bog 
plants. Nothing in the way of technical investigation of the soil factors 
operating in them has yet been prosecuted, but one thing is certain, 
viz: that the factor of low temperatures which is so characteristic of 
northern bogs may be ruled out. This leaves the soil toxin theory as 
furnishing the most probable explanation of the physiological dryness 
of this habitat. 
One very striking fact regarding the distribution of Myrica within 
the formation has been observed. This plant disappears where the sand 
disappears from the soil, i. e., in muck and peat soils, Myrica is almost 
certain to be absent. 
Though present in the small openings in this formation, Sphagnum 
never succeeds beyond a very minor role; the climatic growth condi¬ 
tions are too favorable for the development of the shade-producing 
vegetation, hence the inability of Sphagnum to become even a local 
dominant. 
Successional Delations. Space will not permit an analysis of the 
intra-formation successions. 
In upland semi-swamp areas, where the pine association has been 
removed, this community is almost certain to come in and maintain 
itself even in the presence of frequent fires. Pines (especially P. sero- 
tina) will almost always be found scattered through it, but in its maxi¬ 
mum development, these are never dominant. 
Once this formation has assumed a full control of an area, it may 
persist for a sufficiently long period of time to make it a sub-climax. 
The deep shade it produces tends to prevent the pines from appearing in 
it. Under conditions of frequent fire, the community is quickly 
restored from the underground stem structures. If the Campulosus- 
Sarracenia formation adjoins this community, fire will tend to open 
up the Ilex-Myrica complex to the savannah plants so that, provided 
the soil conditions are right, the Ilex-Myrica formation will be suc¬ 
ceeded by the herbaceous savannah community. 
6. Campulosus-Sarracenia (Campulosus aromaticus, Sarracenia 
flava). Savannah Land. 
Distribution. Locally in that part of the lower or eastern half 
of the Coastal Plain lying south of the Hatteras axis. This formation 
occurs only on the practically level Chowan and Pamlico Terraces 
formed in Pleistocene time. 
