SAND DUNES AND SALT MARSHES 



vegetation of the third zone. The thatch is 

 a sturdy grass, a wonderfully strong but pli- 

 ant fringer of the creeks. It grows from two 

 to five or even six feet high, and bears great 

 waving plrunes of simple straw-colored flow- 

 ers and seeds. One always sinks into soft 

 mud when struggling through it, for it is a 

 great builder-up of the marshes and holds the 

 fine detritus among its stalks and roots. The 

 thatch is prized for bedding and for mulch, 

 but most of that which is cut is carried off 

 by the tides before it is harvested, and that 

 which escapes the scythe is broken off by the 

 ice and lines the edges of the marsh in great 

 windrows,— not a spear is left standing after 

 the winter. As a mulch for trees or shrubs 

 it has no equal, for it is of course entirely free 

 from weed seeds, and with the spring it dis- 

 integrates and loosens and enriches the soil. 



The third zone is that of the salt-grass or 

 marsh hay proper. This constitutes the 

 firmer part of the marsh, reached only once 

 or twice a month by the tides, where one may 

 walk fairly dry shod if he instinctively and 

 from long practice knows how to avoid em- 

 bryo creeks, concealed ditches and treacher- 

 ous sloughs,— the good old name used by Bun- 



192 



