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ECOLOGICAL NOTES ON TWO SOUTH YORKS. 
MARSHES. 
H. H. CORBETT, M.R.C.S. 
AMONG the few remaining bits of unreclaimed marsh that are 
still to be seen in the low-lying land to the east and north of 
Doncaster, are Askern Bog or Askern Mather, adjoining 
Sutton Common, and Kilham Marsh, near Cantley. These, 
although similar in many points have yet so much that is 
distinct in their respective plant associations that comparison 
is interesting. 
The bog at Askern is formed by the water from springs 
issuing from the Permian limestone rocks that here rise some- 
what steeply from the level clay-covered ground of Sutton 
Common. The water of the springs is charged with lime, both 
_ in solution and suspension, and this mingling with the clay and 
vegetable humus makes a marly soil. Artificial drainage 
has now rendered the greater portion of the common fit for 
grazing, but a considerable area is still uncultivated. The 
bog is divided longitudinally by a long, narrow and irregularly 
shaped pool. The western portion, between the Askern to 
Doncaster road and the pool, has a sulphur water well near 
the middle. By the gate near the pump keeper’s cottage is 
some cultivated ground which soon yields place to rank marsh 
vegetation consisting of Phragmites communis and Spiraea 
Ulmaria, Following this on the pool side is an alder scrub, 
while nearly all the rest of the marsh, except the margin of the 
pool, is dominated by Juncus obtusiflorus. This rush, usually 
considered rare, grows in such dense profusion that one can 
walk on it dry shod where the surface of the ground is covered 
with water. Sub-dominant in the juncus marsh are :— 
Spiraea Ulmaria, Carex Goodenowi, growing in large patches, 
Molinia cerulea, Galium uliginosum, and Hydrocotyle. 
Crossing the juncus marsh is a broad belt of Glyceria 
aquatica with clumps of Epilobium hirsutum, marking the 
site of an old drain. Each side of the belt is fringed with Ivis 
Pseudacorus. Scattered over the marsh, but less abundant 
than the plants already mentioned are :—Thalictrum flavum, 
Cnicus palustris and Lychnis Flos-cucul1; while many other 
species occur among which are Parnassia palustris, Orchis 
latifolia and Schoenus nigricans. Dividing the juncus marsh 
from the pool margin is a narrow alder scrub with Lysimachia 
vulgaris, Lythrum Ealicaria and Rubus dumetorum as sub- 
dominant. Here below the alders is also a rich profusion of 
Lastraea Thelypteris. Between the alders and the pool is a wide 
water-logged swamp, usually too wet to be investigated, but 
Naturalist, 
