Genus Statue as represented at Blakeney Point . /. 241 
it. 1 2 The underground parts of S. binervosa consist of a short stout stem, 
which branches profusely at the apex, and which below passes over into 
a long, stout root of wire-like consistency. The plant has a rosette habit, 
and shows no signs of any rejuvenation by budding. 
A slightly different habitat, in which S. binervosa often occurs abun- 
dantly, is the shingle low, a depression left between closely juxtaposed 
banks ; it occurs especially at the convergence of laterals near their junction 
with the Main bank, and being accessible to the highest tides and at the same 
time secluded and tranquil, a covering of mud of greater or less thickness 
becomes deposited over the shingle. The lower part of such shingle lows is 
the main habitat of 6'. bellidifolia , while on the higher margins 5. binervosa 
occurs. The lows are frequently very muddy, but in some parts, where the 
tide rarely floods the low, and where, owing to the near presence of dunes, 
abundance of sand is available, the lows may be distinctly sandy. Finally, 
if the tide is cut off entirely, the binervosa zone may gradually spread centri- 
petally amongst the Suae da hummocks. Accumulation of sand, however, 
soon results in the extermination of the Statice and its replacement by the 
dune flora. 
Speaking generally, though the flanks of the lateral banks form the 
main habitat of the plant, yet the most luxuriant specimens are those 
from the crest. Here, since the fixity of the shingle is increased, the 
rate of accretion of the soil is accelerated, and the growth of S. biner- 
vosa is favoured, until, with the establishment of other plants, the factor 
of competition comes into play and the binervosa zone is driven lower down 
the flanks, and only relict plants are able to survive on the crest. In this 
connexion Salisbury gives some interesting data as to the average height 
and general vigour both of S. binervosa and also of the somewhat parallel 
case of Plant ago Coronopus. For example, the average height of crest 
plants of S', binervosa is 8*5" as compared with 4*1 8 /r for plants from the 
flanks. The explanation given by Salisbury is as follows : 2 e under the 
rigorous conditions of the sloping flanks, the Statice abounds through the 
absence of its less hardy competitors, but with the accretion of soil the 
limiting factor for these latter is removed and only the more robust of 
the Statices survive the ensuing struggle : these from their perennial char- 
acter may remain for a considerable number of years, and by virtue of the 
2" of soil in which they grow, they will be better nourished and therefore 
larger than those of the flanks which are rooted in bare or nearly bare 
shingle.’ 
Relict plants of S . binervosa also occur near the base of a lateral where 
they become buried by the advancing shingle fans of the Main bank. Such 
1 Oliver, F. W., and Salisbury, E. J. : Vegetation and Mobile Ground as illustrated by Suaeda 
fructicosa on Shingle. Journ. of Ecol., vol. i, 1913, p. 249. 
2 Loc. cit., reprint, p. 38. 
