1912-13.] BOTANICAL SOCIETY OF EDINBURGH 181 



At places round the outer margin of the reed-swamp 

 occur a few plants of Ranunculus Flam/mula, Linn... 

 Calth'i palustris, Linn.. Cardamine pratensis, Linn., 0. 

 hvrsuta,IJum., Viola palustris, Linn., Myt sotis Sc 

 Linn.. J uncus effasus, Linn.. Ca/rex Goodenowii, Gay. and 

 Glyceria fluitans, Br. The tree- beside the pond are 

 BetuL.i alba, Linn.. Alnua rotund [folia. Mill.. Sal 

 purpurea, Linn.. S. phylicifolia (Linn.i. Sin., and some 

 Conifers. Around the roots of these trees and on the 

 ground near them are Polytrichum commune, Linn., 

 Gatharinea undulota. W. et M. .and H • ium squar- 



rosum, B. et $.. while on the side of the pond from which 

 trees are absent is a considerable quantity of Sphagnum 

 aeutifolium, Ehrhart. A marked feature of the associa- 

 tions is the absence of Phragmites communis, Trim 

 Phragin not always, however, a companion of 



Stratiotes in native associations. Fleroff (3) describes the 

 vegetation of some shallow lakes and marshes in the 

 Wladimir district of Central Russia, where St 

 abundant. Near the village of Polubarskoje N 



» dated in the open water with Lemna minor. On the 

 edge of this open water there are. here and there, plants 

 of Oicuta virosa, Can 'lis, Curt., and 0. striata, Good. 



Phragmites settles down after a hrni foundation has been 

 made by these plants. As plants of Phragmites die. an 

 Alder marsh gradually rises on their remains. At other 

 places on the lake, instead of Ph. ragm ites there appear thick 

 masses of Typha latifolia. And with Typha are associated 

 Oieuta virosa, Carices and Alders and Birch shrubs. 



From this it appears that Phragmites communis and 

 Typha latifolia are interchangeable companions of Strat 



a. however, is constantly associated with it on these 

 Russian lakes. 



On the Norfolk Broads, according to Miss Pallia (4), 

 Stratiotes is regularly associated with Ranunculus 

 cirevi Sibth., and MyriophyUum turn, Linn., or 



M. verticittatum, Linn. Typha a/ngustifolia, Linn., and 

 Phragmites communis are dominant in the reed-swamp, 

 both open and closed, while Gicuta virosa is present 

 in the closed reed-swamp, on the free water side, on the 

 Broads of the River Ant. 



TBANS. BOT. 50C. EDI>\ VOL. XXVI. 13 



