THE BOOK OF NATURE STUDY 



2. The Cotton Grass or Eriophorum association, with the 

 Cotton Grass dominant. 



Both these have already been fully 

 treated in connection with the vegeta- 

 tion of moorlands (Vol. IV.) 



3. The Juncus Sphagnum associa- 

 tion. This is found at an altitude of 

 nearly 2000 feet. The Sphagnum 

 and the Hair Moss (Polytrichum) form 

 a dense undergrowth, sometimes a 

 foot in height, whilst the Common 

 Rush (Juncus communis) and some- 

 times other species form a thick 

 overgrowth. In this association the 

 Rushes and the Mosses are equally 

 dominant ; it is not developed on 

 thick peat, but rather in soil which 

 contains plenty of humus material 

 and water which is not stagnant but 

 slowly moving. The sub-dominant 

 plants are : Lesser Spearwort, Ling, 

 Red Rattle, Sheep's Sorrel, some 

 Carices, Bedstraws, and Grasses. 

 Sometimes the insectivorous plants, 

 Sundew and Butterwort, occur ; it 

 depends, in part at any rate, on how 

 water-logged the ground is. 



The vegetation of the Fen coun- 

 try affords considerable material 

 for observations of all kinds. In 

 no part of England has the influence 

 of man been greater. Hardly any of 

 the original fen remains untouched; 

 only at Wicken is it possible to 

 see the flora that used to cover 

 the whole district. Nearly all the 



FIG. 12. Lesser Spearwort Fen country has been drained and 

 (Ranunculus Fiammuia}. reduced to cultivation, each field, be 



