Consultant Ecologist

Denis J Vickers BSc(Hons), FLS, CBiol, MRSB, MCIEEM

A Brief Account of the Flora Of Phillack Towans (August 1987)

By Denis J Vickers

© Copyright Tony Atkin and licensed for reuse under this Creative Commons Licence

 

Summary:

Over ten days in mid-August 1987 (9th. to the 19th.) a survey of the vascular plants of Phillack Towans was conducted.

The area under study was divided up into three zones to facilitate species recording.  As many vascular plants as possible were recorded in each zone. Overall 114 taxa of plants were listed and placed in taxonomic order.  An indication of their location and relative abundance was given. Casual recording of faunal species, which could be readily identified, was also undertaken.

 

Location:

Phillack Towans, (sand dunes) are located about 1.5 km north-east of the town of Hayle in the county of Cornwall (Ordnance Survey reference SW 57,39). To the north are St. Ives Bay and the Atlantic Ocean. To the west is the River Hayle estuary and to the south some minor tributaries of the River Hayle. Part of the town of Hayle lies on the lower slopes of the dunes sandwiched between their higher reaches and tributaries of the river.

Brief Description:

The area of the Towans has an average elevation of around 50 m but parts rise to over 70 m. Storms from the Atlantic Ocean and heavy trampling by people has caused the ocean-side of the dunes to erode.  However, the Nature Conservancy Council (NCC) have fenced-off these areas and extensive replanting with Marram grass carried out.  The dunes support a great variety of wildlife: Rabbits are abundant; the whole area is riddled with their warrens.  The grazing by these animals obviously plays a great part in the recycling of nutrients - their droppings are everywhere.  Burrowing by rabbits must also lead to a certain degree of destabilisation of the dunes. The damp Atlantic weather, amongst other things, makes it possible for a variety of molluscs to be abundant over the whole area. The influence of these animals on the flora and subsequently, the dune system must be considerable.  Additionally, many, insects occur on the dunes, no real attempt was made to catalogue them.  However, Lepidoptera includes: The Common Blue, Small Tortoiseshell and Peacock butterflies, and Cinnabar and Six-spot Burnet moths. This rich invertebrate fauna in turn supports many species of birds:  Thrushes are common, so are members of the gull family the most familiar being the Great Black-backed, Herring and Black-headed Gulls, but by far the most frequently observed birds are the crows and there allies.  The Carrion Crow, Magpie and Jackdaw are all very common. Rooks are often seen too but not so frequently near to the ocean.  The dunes also support Adder and Grass-snake.  The Common Toad is a very familiar sight, particularly of a night.

The Recording Zones:

To record the flora of the dunes the study area was divided up into three-zones.  These were marked in red on a map of the area (see Google Earth aerial image above) and referred to in the list of vascular plants recorded i.e. zones 1, 2 and 3.  Although there are similarities between all three, each zone exhibited its own characteristics too, ranging from disturbed (urban and agricultural) habitats near Hayle to maritime type habitats:

  • Zone 1 is nearest to town and backs on to the tributaries of the River Hayle and thus has some dwellings within its boundaries. It is a relatively dry area with a flora more characteristic of disturbed ground, which includes a number of garden escapes as well as supporting a number of familiar dune species.
  • Zone 2 is much damper; its plants are more typical of rough grassland on the chalk downs as many species prefer calcareous substrate.  Within the limits of this zone is a small wet depression, surrounded by Salix spp. and Purple Loosestrife.  Within the water is the Canadian Pondweed and a thriving community or water snails.
  • Zone 3 is drier and dominated by maritime and sub-maritime plants the most notable being Marram grass, the pioneer coloniser that binds the loose sand together.

There are no tall trees anywhere on the dunes as no doubt the Atlantic gales and steep unstable slopes prohibit this, however, there are many small shrubs etc., the most common are the Elder, Privet and Bramble (which occurs in all three zones).

 

The Sand:

As previously mentioned, there are many molluscs living on the flora of the dunes, many of these are snails, their shells are rich in calcium carbonate (CaCO3); further, a large number of plants have a preference for a calcareous substrate.  The underlying bedrock is of hard slate low in calcium carbonate.  Most of the CaCO3 originates from the remnants of shells of marine animals and actually composes something like 70% of the sand by weight. The great number of snails living on the dunes must help to keep calcium carbonate circulating in the dune system.  As may be expected the texture and composition of the sand alters from the freshly laid seaward zone through to that stable enough to build upon in zone one:

  • The sand of Zone 1 contains a sizeable proportion of fine grains, but additionally, more coarse material too.  Nevertheless, the average grain size is about the same as that of Zone 2 at 0.3 mm.  It has around 8% by volume clay and about 2.5% organic matter.  In this zone common salt, sodium chloride (NaCl) content is approximately 0.018%;
  • Zone 2 sand is of more uniform composition than that of Zone 1 and comprises a greater proportion of finer grains than Zone 3. The average grain diameter is around 0.3 mm.  This sand also contains (by volume) around 2.5% clay and about 4% organics.  The NaCl content, as may be expected, is a little higher than above at 0.02%;
  • In Zone 3 the sand is relatively course, with most of the grains about the same size (around 0.4 mm diameter). It contains very little clay or organic matter. It also has a small percentage of NaCl derived from sea-spray etc. of around 0.03% (as expected, higher than the previous two zones) and is, no doubt, variable depending on wind, waves and precipitation.

© Copyright Eryka Hurst and licensed for reuse under this Creative Commons Licence

The Plant List:

In the following plant list location is shown in zones, an indication of apparent abundance is given for each species in each zone. ‘xxx’ is abundant or locally dominant, 'xx" is frequent or locally common, ‘x’ is occasional or rare.  A blank space indicates that the plant in question has not been observed in that zone and not particularly that it is absent.  It must be remembered that these observations were made in mid to late summer - some particularly early-flowering species could have been overlooked.  The Flora of the British Isles, 2nd edition 1962, by Clapham, Tutin and Warburg and the Excursion Flora, 3rd edition 1981, by the same authors (both Cambridge Press) were consulted on the plant nomenclature (there has been considerable revision of plant classification and nomenclature since these publications).

      Zones  
    1 2 3
PTERIDOPHYTA        
Equisetaceae        
COMMON HORSETAIL Equisetum arvense   x  
Hypolepidaceae        
BRACKEN Pteridium aquilinum xxx x  
Polypodiaceae        
HART’S-TONGUE Phyllitis scolopendrium xx    
ANGIOSPERMS: DICOTYLEDONS        
Ranunculaceae        
TRAVELLOR'S-JOY Clematis vitalba   x xx
CEEEPING BUTTERCUP Ranunculus repens xx x  
Papaveraceae        
CORN POPPY Papavar rhoeas x    
Fumariaceae        
FUMITORY Fumaria officinallis x    
Cruciferae        
WILD CABBAGE Brassica oleracea x    
CHARLOCK Sinapsis arvensis xx x  
Resedaceae        
WELD Reseda luteola xx x  
Caryophyllaceae        
BLADDER CAMPION Silene vulgaris   x  
RED CAMPION S. dioica   xx x
WHITE CAMPION S. alba xxx xx x
Chenopodiaceae        
FAT HEN Chenopodium album x    
SEA BEET Beta vulgaris maritima   x  
Malvaceae        
COMMON MALLOW Malva sylvesrtris x    
Geraniaceae        
HERB ROBERT Geranium robertianum x    
COMMON STORK'S-BILL Erodium cicutarium   xx x
Aceraceae        
SYCAMORE Acer pseudoplatanus x    
Papilionaceae        
GORSE Ulex europaeus xx x  
RESTHARROW Uronis repens x xxx xx
BLACK MEDICK Medicago lupulina x xx x
RED CLOVER Trifolium pratense x x  
WHITE CLOVER T. repens x xx x
COMMON BIRD’S-FOOT TREFOIL Lotus corniculatus x xx xx
KIDNEY VETCH Anthyllis vulneraria   x xx
Rosaceae        
BRAMBLE Rubus fruticosus agg. xxx xxx xxx
SILVERWEED Potentilla anserina x xx x
CREEPING CINQUEFOIL P.reptans xx x  
Crassulaceae        
WALL BEPPER Sedum acre   x  
Elaeagnaceae        
SEA BUCKTHORN Hippophae rhamnoides   xx x
Lythraceae        
PURPLE LOOSETRIFE Lythrum salicaria   x  
Onagraceae        
GREAT WILLOWHERB Epilobium hirsutum x    
AMERICAN WILLOWHERB E.adenocaulon x    
ROSEBAY Chamaenerion angustifolium x    
EVENING PRIMROSE Oenothera erythrosepala x xxx x
Araliaceae        
IVY Hedera helix xx x  
Umbeliferae        
COW PARSLEY Anthriscus sylvestris x    
FOOL’S-WATERCRESS Apium nodiflorum x    
ROCK SAMPHIRE Crithmum maritimum     x
FENNEL Foeniculum vulgare xx    
HOGWEED Heracleum sphondylium xx x  
WILD CARROT Daucus carota xx xxx xxx
Euphorbiaceae        
SUN SPURGE Euphorbia helioscopia x    
SEA SPURGE E. paralias     x
Polygonaceae        
JAPANESE KNOTWEED Polygonum cuspidatum x    
CURLED DOCK Rumex crispus x x x
ARGENTINE DOCK R. frutescens   x  
Urticaceae        
STINGING NETTLE Urtica dioica x    
Salicaceae        
PUSSY WILLOW Salix caprea x    
GREY WILLOW S. cinerea xx    
Plumbaginaceae        
THRIFT Armeria maritima x xx  
Primulaceae        
SCARLET PIMPERNEL Anagallis arvensis xx x  
Buddlejaceae        
BUDDLEIA Buddleja davadii x x  
Oleaceae        
PRIVET Ligustrum vulgare xx xx x
Boraginaceae        
COMFREY Symphytum officinalis   x  
VIPERS-BUGLOSS Echium vulgare xxx xx  
Convolvulaceae        
BINDWEED Convolvulus arvense xx xx x
BELLBINE Calystegia sepium sepium xxx xx x
BELLBINE C. sepium sylvatica x x  
SEA BINDWEED C. soldanella     x
Solanaceae        
BITTERSWEET Solanum dulcamara xx xx xx
Scrophulariaceae        
BUXBAUM’S SPEEDWELL Veronica persica x    
YELLOW RATTLE Rhinanthus minor   x  
EYEBRIGHT Euphrasia officinalis xx xxx xx
Acanthaceae        
BEAR’S-BREECH Acanthus mollis   x  
Verbenaceae        
VERVIAN Verbena officinalis x    
Labiatae        
WATER MINT Mentha aquatica   xx  
APPLE MINT M. rotundifolia x    
WILD THYME Thymus praecox x xxx xx
BLACK HOREHOUND Ballota nigra x    
WHITE DEAD-NETTLE Lamium album x    
PLANTAGINACEAE        
RAT’S-TAIL PLANTAIN Plantago major x    
RIBWORT PLANTAIN P. lanceolata x xxx xx
SEA PLANTAIN P. maritima     x
BUCKSHORN PLAIITAIN P. coronopus xx xxx xx
Campanulaceae        
CANTERBURY BELL Campanula media x    
Rubiaceae        
LADY’S-BEDSTRAW Galium verum xxx xxx xx
GOOSEGRASS G.aparine x    
Caprifoliaceae        
ELDER Sambucus nigra xx xx xx
HONEYSUCKLE Lonicera periclymenum     x
Compositae        
COMMON RAGWORT Senecio jacebaea xx xxx x
COMMON FLEABANE Pulicaria dysenterica xx x  
DAISY Bellis perennis x xx x
HEMP AGRIMONY Eupatorium cannabinum x x  
PINEAPPLE WEED Matricaria matricarioides x    
YARROW Achillea  millefolium x x  
CARLINE THISTLE Carlina vulgaris   x xx
MUGWORT Artemisia vulgaris x x  
SPEAR THISTLE Cirsium vulgare x xx x
CREEPING THISTLE Cirsium arvense xx xx x
MILK THISTLE Silybum marianum   x  
GREATER KNAPWEED Centaurea scabiosa xx x  
HARDHEADS C. nigra xx x  
NIPPLEWORT Lapsana communis x    
AUTUMNAL HAWKBIT Leotondon autumnalis x xx x
LESSER HAWKIBIT L. taraxacoides x x xx
PRICKLY SOW-THISTLE Sonchus asper   x x
ROUGH HAWKSBEARD Crepis biennis     x
DANDELION Taraxacum offcinale agg.   x  
ANGIOSPERMS: MONOCOTYLEDONS        
Hydrocharitaceae .        
CANADIAN PONDWEED Elodea canadensis   xx  
Iridaceae        
MONTBRETIA Tritonia x crocosmiflora xx x  
Orchidaceae        
PYRAMIDAL ORCHID Anacamptis pyramaidalis   x x
Cyperaceae        
SAND SEDGE Carex arenaria   x xx
Gramineae        
RED FESCUE Festuca rubra xxx xx xx
FERN GRASS Desmazeria rigida   xx  
ANNUAL MEADOW-GRASS Poa annua xx xxx x
COCK’S-FOOT Dactylis glomerata xx x  
UPRIGHT BROME Bromus erectus x xx x
SAND COUCH Elymus farctus   x xx
OATGRASS Arrhenatherum elatius x    
YORKSHIRE FOG HoIcus Ianatus xxx xx x
MARRAM GRASS Ammophilia arenaria   xx xxx
REED Phragmites australis x    

© Copyright Sheila Russell and licensed for reuse under this Creative Commons Licence.

Further information:

 

Cornwall Wildlife Trust: Upton Towans Nature Reserve

Natural England: Gwithian to Mexico Towans SSSI - Citation

Save Our Sand, Hayle, St Ives Bay Save our Sand