POND VEGETATION. 



NORMAN WALKER. 



University of Leeds, 



The aquatic and marsh plant associations described in the 

 following notes were examined in a group of ponds which are 

 situated above the Bramhope railway tunnel, about half a mile 

 south of Bramhope, near Leeds. They lie about 500 feet 

 above sea level, and owe their origin to surface drainage into 

 large shallow excavations made 66 years ago by the removal 



Fig. I. — A shallow muddy pond showing- veg-etation zones. j = Junciis coinmicnis. 

 0= CE7ia>ithe' fstiilosa, e~Eleocharis palitsti-is. s — Spargaiiiiim ramosiim. p=: 

 Potamogeton iiatans. c = Carex vtclgaris. ^ = G!yceria fluitans. The dotted h'nes 

 represent depth zones. The north bank is steep ; the others slope gently to the 

 water's edge. The diagram was made in the wet summer of 1904. During the dry 

 summer of the present year {1905), the level of the water has sunk eight inches and the 

 Sparganitctn extends across the entire pond. 



of clay for the purposes of the tunnel building. The group is 

 distributed over about a quarter of a square mile and includes 

 eig'ht ponds, varying in depth from one to four feet. The 

 largest pond measures 210 x 78 feet and the smallest 54 x 41 feet. 

 In none of the ponds is there either inlet or outlet. 



u 



