166 TRANSACTIONS OF THE [SEss. LXXY. 
the connecting dikes and ditches are very rich in plants, 
such as Siwm latifoliwm, Hottonia, Alisma, Sagittaria, 
Hydrocharis, the great Water Dock (Rumex Hydrolapa- 
thwm), and the rarer Flowering Rush (Butomus umbellatus), 
together with masses of Water-lilies in places, while the 
great enemy of all such species is the Common Reed, which 
is apt to overgrow them periodically and would finally 
smother them if not removed. 
In the ditches of the North we should expect to find 
quite a different set of water-plants. The place of Sagit- 
taria and Hydrocharis is taken by Alisma Plantago, 
Rumex Hydrolapathum is rare and has R. domesticus 
(=aquaticus) for a substitute, Butomus is almost unknown ; 
though Water-lilies and Irises are common enough, and 
in the drier ditches Siwm angustifoliwm represents. S. 
latijoliwm of the Fens. 
The sedge-fen itself furnishes a great variety of plant- 
life. In ancient times, before the mouths of the rivers were 
silted up to the extent of blocking the drainage of the 
country inland, we know that the land was more or less 
afforested, as oaks and other trees are dug up in the heart 
of the Fens, which were rooted in the tenacious soil upon 
which the peat was subsequently deposited. Now Willows 
and seedling Birches are alone in evidence, if we except the 
strips of Poplars planted for shelter in the cultivated land, 
and the various kinds of trees near the villages. As we 
walk up the green droves which intersect -the Fen at 
-Wicken, we have on all sides of us acres of Cladiwm, 
generally flowerless on the comparatively dry portions, but 
flowering freely in the little water-channels and ditches. 
Mixed with this is a large quantity of Calamagrostis 
epigejos and C. lanceolata, which show up more particularly 
where the growth has been lately cut for litter. Here, 
too, the main grass of the Fen, Molinia coerulea, has a 
better chance of shooting up, and our characteristic rush, 
Juncus obtusiflorus, masses itself round every water-hole 
or disused peat-digging. A striking feature of the ditch- 
sides is Carex elata (=stricta), with its peculiar tufted 
growth, while every here and there among the vegetation, 
where the reeds and bushes have not encroached, we find 
the Marsh Pea (Lathyrus palustris), the Fen Violet (Viola 
