PLANTS OF THE SALT-MARSH Al 
found on dry sea-rocks—the Sea Pink (Statice 
Armeria), Scurvy-grass (Cochlearia officinalis), Sea 
Aster (A. Tripolium), and so on; showing that soak- 
ing soil is in no way essential to their growth. (The 
first two reappear among alpine plants on some of 
our higher mountains, pointing again to an analogy 
of conditions not altogether understood.) But the 
salt-marsh formation as a whole is perhaps the most 
distinctive as regards its composition of any of the 
plant-groups of our country. It is dominated by such 
species as the grey leathery-leaved Obione portula- 
coides, the small-leaved, thick-stemmed Sea Pink, the 
Sea Wormwood (Artemisia maritima), which is all 
covered with a silky coat; the pools are fringed with 
Scirpus Tabernemontant, a dwarf greyish copy of the 
Common Bulrush of our lakes, and filled with the 
narrow-leaved Ruppia and Zannichellia; and in the 
muddiest places are little forests of Glasswort, leaf- 
less, very fleshy, the flowers reduced to mere essentials 
and buried in the fleshy stems (Fig. 2, p. 18). 
Again, it is easy to trace the relationship existing 
between plant form and soil conditions in the bog- 
land flora; and these relations, unexpectedly enough, 
turn out to be analogous to those obtaining in the 
case of the salt-marsh. The sodden peat, sour and 
badly aerated, and poor in mineral salts, is poor also 
in the bacteria which feed upon and destroy dead 
vegetable matter, with the consequence that acid 
humus compounds collect in the half-decayed vege- 
table mass; water charged with these substances is as 
unsuitable for plants as is the water of the salt-marsh. 
In spite of the wetness of the peat, water is in this 
case also a desideratum; and the moorland plants, like 
