PELOPHILOUS FORMATION OF LEFT BANK OF SEVERN ESTUARY. 17 
Cochlearia anglica, L., grows at about the level of this zone 
on the sides of streams where it is sheltered from the wind, 
but in the exposed zones the occasional plants met with are always 
in the next higher zone. 
This zone is very characteristic when well developed, and may 
be of considerable width, but at its outer and inner margins it is 
often not true to type. At the outer margin, when this is the 
best drained portion of the zone owing to a sharp fall between 
this zone and the Salicornia zone or mud below, it is very often 
lined with a fringe containing the characteristic plants of the 
Festuca zone above. At the inner margin there is often a curious 
blending of the two other zones, the Salicornia and the Festuca. 
The Salicornia patches obtain a footing where the fall of water 
from the zone above has scoured out the zone to a depth of two 
or three inches below its usual surface. The Festuca association 
patches represent patches of the actual upper zone fallen off from 
above, and not yet converted into the association typical of the 
lower level, a process that may take two or three years to accomplish. 
(III.) Above the Sclerochloa zone, and usually separated from 
it by a fall of two or three feet, though sometimes by five or six, 
there is present a more densely populated zone containing a 
greater number of species owing probably to the less stringently 
saline conditions. This zone varies in regard to its dominant 
plant, but may be termed the Festuca zone after its most common 
dominant, a low growth of the species Festuca rubra, L. But 
occasionally the grass is almost entirely driven out by dense 
patches of other plants, more commonly by tufts of very short 
specimens of Juncus Gerardi, Loiseleur. These two plants are 
the usual dominants of the zone, but in places where a steep fall 
to the next zone has enabled it to drain particularly well, or where 
its height takes it a little further than usual out of reach of the 
tides, then other plants may attain to a partial dominance ; thus 
above Aust, in a particularly well-drained patch which seems 
really to belong- to this zone, the plants occurring as co-dominants 
in addition to Festuca and Juncus are — 
Hordeum nodosum, L. 
Triticum pungens, Persoon. 
Triglochin maritimtim, L. 
The following plants are also usually common in this zone — 
Plantago maritima, L. 
Plantago Coronopus, L. 
Alsine marginata, Reichenbach. 
Glaux maritima, L. 
While very rarely the following have also been found — 
Statice Armeria, L. , few specimens. 
Cochlearia a?ig r lica, L., few specimens— great 
quantities on sheltered banks (see p. n). 
Bttpleurum. tenuissimum , L., one specimen — near 
New Passage. 
