46 



Botany 



that of parts of the Norfolk Broads. This primary succession may be 

 summarised as follows: 



(a) Aquatics. There are no large open areas of water in the fen, and 

 nowhere can we see zonations indicating all the early stages of the hydro- 

 sere, like those described by Miss Pallis on the Norfolk Broads. We may 

 indeed judge the lode and ditch flora in the light of the work of Miss 

 Pallis, and find, in appropriate depths of water, various aquatic plants, which 

 are more or less widespread in the rest of England. The abundant forms 

 include: Chara, Elodea canadensis, Myriophyllum spicatum, Hippnris lud^aris, 

 Potamogeton lucens, P. pectinatus, P. perfoliatiis, P. crispiis, P. densiis, Scirpus 

 acicularis, Sparganimn simplex, Oenanthe phellandritim, Hottonia pahtstris, 

 Castaha alba, Nymphaea httea, Sparganium natans, Sagittaria sagittifoha, 

 Butomus timhellatiis, Alisma plantago, A. rannnciiloides. Ranunculus lingua, 

 Polygonum amphibium, etc. 



Cmc 



ril;icd 5ccl^c Utter 



Bust 5tdrft .---""' ' ^ 



dAfUcttocv Inj Cutting. 



Fig. i6. 



Vegetation Successions at Wicken Fen. 



From H. Godwin and F. R. Bharucha, "Studies in the Ecology of Wicken Fen", 

 Joiint. Ecology, xx, 185 (1932). 



[b) Reed-Su'amp [Phragmitetum). The borders of lodes and ponds and 

 the shallower drains throughout the fen show a reed-swamp o£ Phragmites 

 communis well developed, but only at the eastern end, where the fen peat 

 abuts on the gault clay, do Scirpus lacustris, Typha angustifolia, Glyceria 

 aquatica or Phalaris arundinacea occupy similar marginal positions by the 

 water side. 



