THE COAST-FLORA OF THE CLACTON . DISTRICT. 
201 
-stable and gives rise to a different vegetaion more resembling 
that of the clayey cliff. 
2. Muddy or clayey soil is in many respects the exact 
counterpart of the sandy soil. The particles are finer and more 
cohesive ; its power of retaining water very great. When 
exposed to prolonged drought, however, it becomes as hard as 
stone, thus rendering absorption of water practically impossible. 
Like the sandy soil it occurs in different heights from the sea- 
level, e.g., in the creeks and muddy flats, then on dams which 
have been erected against the inrush of the tide into the reclaimed 
land, and on the cliff itself. 
Plants growing on sandy soil are called Psammophytes or 
Psammophilous (sand-loving) plants and those preferring 
muddy soil Pelophytes or Pelophilous (nrud-loving) plants. 1 
Salt.— The physical nature of the soil does not, however, 
yield the only fundamental test by which to divide the coast- 
flora. The action of the salt contained in the sea-water is 
another. There are plants that are obviously dependent upon 
being more or less often reached by the tide, and whose soil 
and tissues contain a varying amount of chlorine. These 
are called Halophytes or Halophilous plants. There are Psam¬ 
mophilous and Pelophilous Halophytes. On the other hand 
plants grow on the shore that have no need or predilection for 
salt and might grow inland, if they found convenient soils. Thus 
Salicornia (Marsh Samphire) is a Pelophilous Halophyte, Cakile 
(Sea-rocket) a Psammophilous Halophyte, while Psamma 
arenaria (Sea Marram) is said to be a non-Halophilous Psammo- 
phyte, being able to grow quite well at a great distance from 
the sea, if it can find shifting, deep sand to grow upon. 
The percentage of salt in different places varies according 
to the number of submersions by the tide, the number and 
violence of storm-splashes (on sea-walls and cliffs), the amount 
of fresh water introduced either by atmospheric precipitation 
or by the raising of ground-water and the facility of drainage. 
Obviously a depression at a high level, although reached only 
by an exceptionally high tide, may by evaporation become more 
saline than the parts exposed to the daily scour of the brine. 
It must be kept in mind also that the salinity varies, not only 
i This nomenclature is taken from the recent standard-book of Warming : The (Ecology 
of Plants. 
