Reconquest of the Water 



or of Equisetum limosum or of Poa (Glyceria) fluitans, 

 but the commonest and best example of the reed 

 association is Phragmites communis. It is a hardy 

 and common plant, for it grows in New Zealand, 

 America (except the Amazon valley), Mesopotamia, the 

 far north of Europe, and Siberia, in East Turkestan, 

 and in China, as well as all over temperate Europe. 



Its prostrate stems, growing to 40 or 50 feet and 

 giving off hundreds of grasping root-fibres, lie in the 

 water. The foliage and flowering stems, of which one 

 springs up at every 5 or 6 inches of the rhizome, are 

 upright, and even in this country may be 12 feet high. 

 But at Niederlausitz bei Luckau, Friih records a speci- 

 men 33 feet high.'' 



The harshly rustling leaves have a short flexible joint 

 just where they join the sheath, and the plume of 

 purplish white flowers is lifted high above the thicket. 

 These close set battalions of Phragmites stems are the 

 real land-formers, for the submerged main stem is always 

 growing out into the water and so occupying more of 

 the lake. 



But two distinct processes are also at work. In the 

 reed thicket there is a continual accumulation of dead 

 leaves and stalks, of drifted silt from the lake, and also 

 an enormous growth of algae and diatoms. Every 

 season sees layers of fine mud and dead leaves deposited 

 in the reed zone, which gradually becomes shallower, or 

 rather fills up with half liquid mud. 



On the landward side of the reeds, marsh plants 

 creep in between the Phragmites stems and here and 

 there succeed in establishing themselves. The process 

 varies almost with every particular loch, and the 

 number of marsh plants which may be found in 

 such a place is very great indeed. Perhaps the most 

 striking are Lythrum salicaria, spearwort (Ranun- 



131 



