Plants of Chesworth Farm wetland

Looking like a type of thistle, the Common Knapweed (Centaurea nigra) is particularly common in the grass either side of the bird screen. The thick dark heads that give the plant its alternative name of “hard-heads” hold the red-purple fertile florets. These flowers open until late in the season (July-Sept) and provide welcome nectar for a range of insects including bees, hoverflies, butterflies and moths. The seeds subsequently provide a nutritious easily accessible food source for many of our farmland birds.

The purple/lilac flowered and highly-scented Water Mint (Mentha aquatica) is a different plant from the Spearmint (M. spicata) you tend to have with your roast lamb. Its scientific name aquatica says it loves to have its roots well and truly in the water. The sturdy stem, sometimes tinged purple-pink, keeps its flowers well above the water surface. The two or three “pom-pom” flower inflorescences encircle the stem and top off the plant with great show from July to September. These strong-smelling flowers seem to attract a wide range of hoverflies as well as a variety of other pollinating insects.

yellow flag iris copy

Yellow Iris

The Yellow Iris or Flag (Iris pseudacorus) is instantly recognisable. Its bold yellow flowers and spear-like leaves tower over most waterside plants. Each flowering stem gives the impression of an extended flowering period between May and July because the three or four flowers appear on the same stem one after the other.

Regularly mistaken for “just another buttercup” the Lesser Spearwort (Ranunculus flammula) is rather overlooked. However, its close association with water and wet areas in general makes it quite special. It particularly likes areas where water levels vary through the seasons. Use its leaves to tell it apart from the other buttercups on the farm, as they are single and “spear-shaped” rather than the more “hand-like” leaves of the Meadow and Creeping Buttercups.

There are only 38 mature native Black Poplar (Populus nigra ssp betulifolia) trees left in Sussex, and in the UK there are only around 10,000 in total. A tree once frequently found associated with farmsteads, waterways and riverbanks and commonly depicted in many of John Constable’s paintings it has declined through the introduction of hybrids from overseas and habitat loss. The draining of wet meadows and floodplains has significantly reduced their ideal habitat to a fraction of what it once was. Once heavily cultivated over the centuries as a utility tree it has many uses, including wagon bases, clothes pegs and clogs. And, because of its fire resistance, brake blocks, matches and roof trusses of kilns.

Poor natural reproduction over the years has reduced numbers, and most of the mature trees are reaching old age and starting to die. However, efforts to propagate the true Sussex Black Poplar by clone cuttings have benefitted its local population, with newly planted trees in Sussex now reaching up to 25 years old. Previously at threat of ‘genetic’ extinction, the dedicated work of the Millennium Seedbank and others means that for the first time in decades, there are now young, genetically unique trees being grown from some of the old parent trees, and its future is safe. The bark of the tree is very distinctive; it becomes almost black with age, deeply fissured and often with massive burrs. The leaves are almost lime-coloured and heart-shaped, the tree often leans and has branches which sweep up at the tips. There are male and female trees. The striking red male catkins appear in March before the leaves break and hang rather like lamb’s tails. The female flowers appear more “greeny-yellow” and produce copious fluffy seeds.

(For more information on the tree in Sussex see further details on the Sussex Wildlife Trust’s website.)

Meadowsweet (Filipendula ulmaris) is a tall, elegant, white-flowered plant often found in damp places and is certainly at home in these fields. And what a wonderful asset! Throughout history it seems to have cured most illnesses, agues, aches and pains, and provided flavouring to mead and beer: it has also divined thieves, emboldened wavering Russian knights, warded areas free of snakes, and kept evil away. Although some of these claims are rather far-fetched, its qualities as a medicinal plant has some proven use as it contains chemicals similar to aspirin.

Another white-flowered waterside plant, Hemlock Water Dropwort (Oenanthe crocata) is found throughout these two fields, relishing the damp conditions. Although it is said by some to be the most poisonous plant in the UK, livestock appear to be unaffected by eating the leaves. This plant has the typical features of the very large group of plants – the umbellifers. These have umbrella-like flower heads, called an umbel, and include Hogweed, Cow Parsley, Hedge Parsley, Pignut and Angelica, all plants found here.

Other important plants (not shown on the interpretation board)

Cutgrass (Leesia oryzoides) is an endangered grass that is almost exclusively found growing naturally wild on the fringes of the River Arun in West Sussex. In these fields it particularly likes areas where cattle have disturbed and “puddled” wet banks and areas close to slow-flowing water. It lives up to its name, having distinctively rough, cutting edges to its grass blades. For more information on this endangered plant visit the UK and Irish plant atlas.

A complete list of around 110 species of plants that have been found in the wetland fields since 2014 is available here.

Illustration by Helen Joubert Design

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