Il] INDICATOR-PLANTS 33 



And only if the sandy soil is moist and of better quality, 

 owing to a certain proportion of humus, the following, 



Ant/wxanthum odoratum. Arrhenatherum avenaceum. 



Agrostis alba. Arena puhescens. 



Bactylis glonierata. Poa pratensis. 



That the soil contains considerable quantities of 

 common salt — sodium chloride — may be inferred if the 

 foUowinsf grasses occur, 



Fsamma arenaria. Hordeum marithmtm. 



Elymus arenarius. Agropyrum junce^mi, &c. 



The existence of much humus is indicated by such 

 shade grasses as 



Meliea uniflora. Bromus giganteus. 



M. nutans. B. asper. 



Milium effusum. Bracliy podium sylvaticum. 



Whereas soils known as "sour," though containing 

 much vegetable remains, may be suspected if the following- 

 grasses abound on them, 



Aira ccespitosa. Alopecurus geniculatus. 



Nardus stricta. Molinia ccendea ; 



especially if sedges and rushes coexist with them. 



When cuttings are made in forests, such grasses as 

 the following are very apt to appear, and may do harm to 

 young plants, 



Festuca ovina and varieties. Holcus mollis. 



Agrostis alha. Aira Jleoniosa, &c. 



The grasses more especially indicative of particular 

 classes of forest-soils are chiefly the wood-species (see 

 w. 3 



