438 BOTANICAL GAZETTE [ DECEMBER 
ScIRPUS ATROVIRENS Muhl.  Kill-cow (sometimes three- 
square’). In the wettest places, and sometimes abundant, 
replacing the watergrass. 
Of minor importance in this association is 7riglochin maritima L., which 
occurs scattered amongst the broadleaf and watergrass, and appears as much 
at home as upon the Staticetum. Also there occur, in a subordinate réle, 
Thalictrum polygamum Muhl., in occasional patches; “fzlobtum lineare 
Muhl., abundant in places; Lysimachia stricta L.|L. terrestris (L.) B. S. P.], 
abundant; /ris versicolor L.; Campanula aparinoides Pursh; Scutellaria 
galericulata L., and many others of lesser importance. 
The power of the chief members to endure their wet situations 
is sufficiently explained by their capacity for air-storage, and 
their ability to stand some salt by their power of root resistance. 
Of these members at least three, Carex maritima, the broadleaf, 
and the Triglochin, are more or less halophilous, and it is at first 
surprising to find them thriving so well in this situation. It is 
very likely, however, that this position is more salt than it seems, 
for it must receive much of the drainage from the higher marsh 
(to which, as we have seen, much salt is being raised from below 
by evaporation), and this may be the case particularly in the low 
places where Carex maritima abounds. This can only be deter- 
mined by analysis of the soil water in that situation. It may be 
possible, too, that a capacity to endure salt does not carry with 
it any lessened capacity to endure its absence, an important 
point still to be determined. 
The broadleaf is the overwhelmingly dominant member of 
this association, no other approaching it in importance, and it 
often occurs for great areas practically pure. The Cicuta, raising 
most of its foliage above that of the broadleaf, is far the most 
prominent secondary member, but its exact relations with the 
broadleaf, whether of competition, mutual tolerance or mutual 
advantage, remain to be determined. The marginal member 
toward the Phleumetum is the broadleaf itself, as it is toward 
Staticetum. In the former case it meets the Agrostis, and in the 
latter appears upon the matured salt marsh, and no doubt in the 
original unreclaimed condition of the marshes it occupied the 
great areas between the Staticetum and the bogs. The marginal 
member toward the bog is sometimes the broadleaf and some~ 
