2 WONDERS OF PLANT LIFE 



plants. It is possible to realise how keen must 

 have been the competition for a place when we 

 remember that for each plant which has come to 

 perfection several score will have gone down in 

 the struggle. 



Perhaps some of the most aggressive plants 

 in the capturing of positions are those with sub- 

 terranean stems, which run along under the soil, 

 sending up shoots at intervals. Not a few of the 

 grasses are marvellous instances of how much 

 space a single plant may cover. The maritime 

 grass Psamma arenaria, so common on our coast 

 sand-hills, spreads over a huge area of ground, 

 as may be proved by pulling up one of the tufts. 

 It will be found that the long stem may be traced 

 back for several feet to the parent plant. In a 

 very similar manner does the great Bracken Fern 

 thrust out its rhizomes, or underground stems, in 

 all directions, and in this way occupy the ground 

 to the exclusion of almost everything else. In a 

 very large number of cases, however, the stems 

 are simply procumbent, running along on the 

 surface of the soil. The Speedwells, the Poten- 

 tillas and the Strawberries are in this way able to 

 monopolise the situation. 



In one summer a sturdy specimen will succeed 

 in rooting its leaf joints in dozens of places ; these 



