Grasses 153 



The land has its assistants, too, a humble host, 

 whose work is done quietly, and chiefly under- 

 ground, but whose combined aid is invaluable. 

 These are the coast-grasses, whose stems bend to 

 the winds, but whose widely-penetrating roots 

 bind the sands in a network of tough fibres, and 

 defy the encroachments of the waves. 



On the Atlantic seaboard, from Canada to Vir- 

 ginia, the coastwise sand-dunes are overgrown with 

 the " marram-grass" or ''sea sand-reed" (Fig. 37). 



Its strong rootstocks often attain a length of 

 twenty feet or more, and become closely inter- 

 woven, forming a netlike mass which is very re- 

 sistant to the force of wind and sea. Further 

 south the "little panic-grass" takes up the good 

 work, and gives permanence to the coast-lines of 

 Florida and the Gulf States. The running mes- 

 quit of Arizona and the alkali-grass of the plains 

 help to hold in place the shifting soils of the 

 great thirst-lands. Several species of mud-bind- 

 ing grasses give solidity to the shores of the 

 great lakes and render the banks of the Missis- 

 sippi and its tributaries more permanent than they 

 would otherwise be. 



The public services of such grasses as these have 

 been acknowledged in high places. During the 



