Desmoulin's Whorl Snail Vertigo moulinsiana (Dupuy) in Essex
elsewhere. Fields signs indicate that the river is prone to flooding at this site and the sedge beds
may have significant amounts of standing water at times during the winter.
Rushy Mead
This reserve comprises a complex of drains supporting tall Pond-sedge beds, fen-like vegetation,
and large stands of Comfrey Symphytum spp. and Nettle Unica dioica beds. It lies to the east of
the River Stort. Survey work concentrated on the vegetation fringing and within the numerous
internal drainage ditches.
Thorley Flood Pound SSSI
This large site lies between the Stort navigation channel to the east and the London to Cambridge
railway line to the west, close to the old course of the river Stort. It comprises species-rich fen and
sedge beds which, at the time of the survey, were rather dry at the northern end but became
progressively damper towards the south. Reed Canary-grass, Reed Sweet-grass Glyceria maxima,
Meadowsweet Filipendula ulmaria and various rushes are all locally abundant. Centrally on the
eastern boundary is a stand of willow wood over a sparser sedge bed community. The whole site
was divided into 9 sub-units for the purpose of sampling. Survey work extended throughout suitably
damp sedge vegetation, with the larger wet drains being recently dredged and generally devoid of
suitable vegetation, or were too deep to make surveying safe.
Little Hallingbury Marsh SSSI
The majority of this vegetation comprises a mix of Lesser Pond-sedge Carex acutiformis. Water
Horsetail Equisetum fluviatile and Marsh Horsetails E. palustre, Recd Sweet-grass, Branched Bur-
reed Sparganium erectum and a variety of marsh/fenland herbs. Willow scrub is thinly scattered
across the site. It was divided into 5 sub-units, although the extreme eastern end of the site was not
sampled. This relatively small site lacks internal drains and so survey work ranged through the
generally wet fen vegetation.
Sawbridgeworth Marsh SSSI
The eastern side of this comprises species-rich marshy grassland, which slopes down westwards
into extensive stands of Lesser Pond-sedge, Reed Canary-grass and Reed Sweet-grass. Great
Willowherb Epilobium hirsutum, Yellow Flag-iris and Common Reed Phragmites australis are
also locally frequent. Most of the survey work centred on the numerous drainage ditches in the
centre of the site, although some sampling of the open sedge vegetation (recently cut and uncut)
was also undertaken.
Parndon Mill
This site comprises the remnants of a flood plain meadow that has been bisected by the London-
Cambridge railway. It includes a section of old moat, which is fringed with Lesser Pond-sedge.
Most of the site comprises sedge-bed and fen vegetation, although where the ground rises to the
south-east it grades into neutral grassland.
Essex Naturalist (New Series) 21 (2004)
127