SEAWEEDS AND TFIE WATER-FLORA. 1 85 



The West Coast of Scotland, from the Clyde at 

 Renfrew, southwards gives many examples of the most 

 characteristic seaside vegetations in Britain. Near 

 Dumbarton and Langbank, there are great stretches of 

 estuarine mud where are to be found those plants 

 intended by Nature to turn the alluvial silt into good 

 fertile land. From Ardrossan to Ayr is a sand-dune 

 country, which shows very distinctly the changes by 

 which a stretch of barren and desolate sand hillocks 

 may be reclaimed into ordinary meadow or woodland. 

 However, perhaps the most interesting transitions are 

 to be found on the sides of lochs and ponds, and, 

 occasionally, along slow-moving rivers and canals. In 

 these last cases particularly, it will be found that the 

 green surface due to scattered living plants, continues 

 without interruption through the marsh and under the 

 water, so that, even at a depth of nine or ten feet, plants 

 are actively engaged in utilising the light which filters 

 down to them. 



In Scotland lochsides often show the following 

 regular succession of plants. Where the soil becomes 

 water-logged, the ordinary clovers and grasses of the 

 meadow become intermingled with such forms as 

 Ranunculus flaniniula^ and various sedges. This first 

 fringe of marsh plants is followed by : — (2) Eushes often 

 occupying a very narrow width ; (3) Iris or Flag, 

 usually where the water is less than eighteen inches 

 deep ; (4) Reeds such as Scirpus^ or Equisetum limosum^ 

 generally occupying the water from a depth of two 

 feet to four feet six inches ; (5) Floating leaves of 

 the Yellow and White Water-lily — -the rhizomes of 

 these plants are sometimes at a depth of nine feet 

 six inches ; ^ (6) the Pondweed, Potamogeton nutans ; 



^ These measurements were taken at Bearsden, near Glasgow. 



