The fens are home to the nationally rare crested buckler fern.
He constructed "Morton's Dyke" across the fens from Wisbech to Peterborough, repaired the episcopal palace at Hatfield and the school of canon law and St Mary's Church at Oxford.
He also defended the rights of the commoners of Ely threatened by the "adventurers" who had drained the Great Level, and he was nicknamed afterwards by a royalist newspaper "Lord of the Fens."
Obviously no more than this is possible until physiologists are able to state much more precisely than at present what is the influence of common salt on the plants of salt-marshes, of the action of calcium carbonate on plants of calcareous soils, and of the action of humous compounds on plants of fens and peat moors.
Bog Xerophytes live in the peaty soil of fens and moors which are physically wet, but which are said to be physiologically dry.