level and our anthropogenic sea walls. On a visit to Heybridge Basin recently, a walk round
the sea wall south from the marina, at the end of the canal, revealed that not all our salt marsh
plants are giving up as their characteristic zone is pushed up against the sea wall. This wall
has been faced with a sloping facade of concrete blocks, set in pitch, in a rectangular matrix.
Along the pitch junction just above the second row of blocks a dense line of Golden Samphire
Inula crithmoides has established itself, and Lax-flowered Sea Lavender Limonium humile
is also moving up from the very top of the saltings onto the wall, with more plants now on the
wall than on the marsh. Further round the estuary, east from the Osea Island causeway, L.
humile is present in a line along the base of the wall.
This phenomenon obviously needs investigating fully and ideally monitoring over the next
few decades, as these two species in particular are largely confined to our East Anglian
coasts. How about some cash English Nature?
Returning to the canal, although the Great Water-dock Rumex hydrolapathum is still doing
very well in between the boat moorings, large rafts of the aquatic alien Hydrocotyle
ranunculoides are still in evidence, providing in places a moored floating raft for piggyback
colonies of watercress. Like the dreaded Water Hyacinth of tropical waters world wide, the
Hydrocotyle, an alien from N. America, has adapted to cope with rapidly rising water levels
in the rainy season by developing a floating form. It formerly infested the R. Roding but now
seems to have been effectively eliminated. Along the Chelmer-Blackwater canal however it
seems to be a losing battle.
Plenty of salt and now some pepper
Ken Adams 63 Wroths Path, Baldwins Hill, Loughton. IG10 1SH. 020 8508 7863.
Over the last 20 yrs, with the use of the corrosive common salt (NaCl) as a de-icing agent on our
roads instead of the milder CaCl2, to the delight of manufacturers our cars rust away even faster.
Our roadside verges and centre reservations, howevei", have come to resemble the salt deserts of
central Spain. Numerous species of salt tolerant plants have now colonised the verges of most
of our motorways, A class and many B class roads. Up until now the most spectacular being
Danish Scurvy-grass Cochlearia danica, which decorates our otherwise bare verges and splash
zone roadside banks with its carpets of small white flowers in late March and April. In the last
five years however the largest of the pepperworts, Dittander, Lepidium latifolium has suddenly
taken to our verges. Formerly a very local plant of sea walls and waste ground near the coast in
north cast Essex, it has spread out from Colchester north along the A12, and west along A120,
in localised patches, favouring gravel verge/centre reservation in fills, but seemingly also at
home in the cracks between concrete slabs. At the A12/A120 junction it grows on the concrete
bridge parapet. Along the A12 it is abundant on both verges and the centre reservation of the
dual carriageway down into the Stour valley at Dedham, and along the A120 it has made its way
in isolated verge patches to Coggeshall.
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Essex Field Club Newsletter No. 42, September 2003