Barb if you look closely on the map (may be you must change scale) you see the lilies occur in a rather green area which I think indicates dampness. From memory at one of our woody work parties last year south of Oldfields Lane there were rather wet areas which were soaked and had a number of species that you would expect in moist areas, for example your record of Eleocharis Eleocharis acuta (Common Spike-rush)