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The Essex Naturalist
Reed hover at Old Hall Marshes Nature Reserve
The Colchester Natural History Society is currently engaged in recording the
natural history of the RSPB reserve at Old Hall Marshes, Tollesbury and I, as
Botanical Recorder, am covering the flora. During 1998 I had two visits (28th
August & 17th September) to the reedbed compartment. This includes a mosaic
of grassland, an old decoy pond and many dykes, some of natural origin, and
some man-made. In four places within these dykes the vegetation has formed
floating platforms (hovers) and it was these that were visited.
The basic components are lesser reedmace Typha angustifolia L. and common
reed Phragmites australis (Cav.) Trin. ex Steud., amongst which can be found
such plants as grey clubrush Schoenoplectus tabernaemontani (C.C. Gmel.) Palla,
water dock Rumex hydrolapathum Huds., broad buckler fern, Dryopteris dilatata
(Hoffm.) A. Gray, gipsywort Lycopus europaeus L. and woody nightshade
Solanum dulcamara L.. However, this habitat also proved to be a new location for
some scarce Essex species. These include the following:
Marsh Willowherb Epilobium palustre L. In total, 17 plants were found in three
areas of hover. Jermyn (1974, Flora of Essex.) gives 11 sites for the county, the
closest of which was Layer de la Haye and Gibson (1862, Flora of Essex.) listed
Tiptree Heath. Since 1980 it has been recorded from a bog in Epping Forest and
at Backwarden, Danbury. Also present at this latter site was Sphagnum fimbriatum
as it was in another bog in Epping Forest where marsh Willowherb had been
recorded in 1975.
Sphagnum fimbriatum Wils, and S. squarrosum Crome were found in one area
of hover. The former was scarce, being present in small quantity, whilst the
latter was frequent with several large (2ft.) diameter and several smaller patches.
Whilst S. fimbriatum is the commoner of the two species in the county both are
restricted due to lack of suitable habitat and have less than 20 records each
dated 1980 or later. These records are mainly from bogs in Epping Forest,
woodland ponds or gravel workings. The record for S. fimbriatum is a new ten-
kilometre square record for Essex but S. squarrosum had previously been
recorded at Pods Wood, Tiptree, in 1860.
In all areas of hover heavily galled woody nightshade was noticed and Jerry
Bowdrey has identified the gall-causer as Eriophyes cladophthirus (Nalepa) - a gall
mite. This is the second record, the mite previously having been found in a
similar habitat, in a brackish marsh at Aveley.
Acknowledgements
I would like to thank Tim Pyner for identifying the Sphagnum and Dr Ken
Adams for the information on the county status of the above species.
- TERRI Tarpey, 33 Bristol Road, Colchester, Essex CO1 2YU.