Constant species

Poa annua, Taraxacum officinale agg.

Physiognomy

The Poa annua-Taraxacum officinale agg. community comprises more or less open coarse weedy vegetation in which Poa annua and various dandelions are the sole constants. Plantago major is frequent throughout and Senecio vulgaris, Chamomilla suaveolens, Lolium perenne and Stellaria media are common in various of the sub-communities but otherwise only Sagina procumbens and Bromus sterilis are more than scarce.

Sub-communities

Senecio vulgaris sub-community. Apart from the two community constants and Plantago major, only Senecio vulgaris and S. squalidus are frequent here with Cerastium fontanum, Matricaria maritima, Holcus lanatus and Veronica arvensis occasional.

Cirsium vulgare-C. arvense sub-community. L. perenne and C. suaveolens join Poa annua and Taraxacum officinale agg. as constants in this sub-community and Stellaria media and Trifolium repens are common but more distinctive is the high frequency of the coarse tall herbs Cirsium vulgare, C. arvense, Rumex obtusifolius, R. crispus and Chenopodium album.

Crepis vesicaria-Epilobium adenocaulon sub-community. C. suaveolens and P. major remain as frequent associates here but more distinctively preferential are Crepis vesicaria and Epilobium adenocaulon with Sonchus oleraceus, Poa trivialis, Trifolium dubium, Cardamine hirsuta, Coronopus didymus and Capsella bursa-pastoris occasional.

Habitat

The Poa-Taraxacum community occurs on disturbed, but only lightly trampled, loamy soils along tracksides, pathways, wall-bottoms, pavement edges and road verges, in gardens, farm fields and on waste ground.

Constant species

Cirsium arvense, Urtica dioica.

Physiognomy

The Urtica dioica-Cirsium arvense community typically has a rather open or patchy cover of U. dioica, usually grown tall by mid-summer but not so densely developed as to exclude other associates. Among these companions, large thistles and coarse grasses are the most conspicuous, with Cirsium arvense and C. vulgare both occurring frequently, and often in some abundance, and Dactylis glomerata, Elymus repens, Holcus lanatus and Arrhenatherum elatius very common in various of the sub-communities. Galium aparine is occasional, its shoots sprawling over the taller herbs, and there can be scattered plants of Lamium purpureum, Leucanthemum vulgare, Epilobium hirsutum and Carduus acanthoides.

Sub-communities

Holcus lantus-Poa annua sub-community. Elymus repens and Holcus lanatus with, somewhat less frequently, Poa annua and Agrostis stolonifera give a distinctly grassy look to this vegetation and there is often some Sonchus asper, S. oleraceus, Senecio vulgaris, Daucus carota, Rumex obtusifolius and Echium vulgare. Locally, Pteridium aquilinum can figure. Smaller associates in more open places among this tall and coarse herb cover include Cerastium fontanum, Trifolium repens, T. pratense and Myosotis arvensis and Vicia sativa is an occasional climber.

Rumex obtusifolius-Artemisia vulgaris sub-community. Elymus repens, Dactylis glomerata and Arrhenatherum elatius are frequent here, along with the nettle and thistles, but the most distinctive feature is the common occurrence of Artemisia vulgaris and Heracleum sphondylium with occasional Calystegia sepium, Malva sylvestris and Conium maculatum.

Synonymy

Pteridietum aquilini Goodman & Gillham 1954 p.p.; Endymio-Armerietum maritimae Malloch 1971.

Constant species

Festuca rubra, Hyacinthoides non-scripta, Rumex acetosa, Holcus lanatus.

Rare species

Scilla verna.

Physiognomy

The Festuca-Hyacinthoides community comprises a lush carpet of F. rubra and H. non-scripta with Holcus lanatus (sometimes abundant) and scattered plants of Rumex acetosa. Few other species are uniformly frequent throughout but Daucus carota ssp. gummifer occurs occasionally. Scilla verna and Sedum telephium are distinctive at low frequencies.

Sub-communities

Armeria maritima sub-community: Endymio-Armerietum maritimae, Cochlearia officinalis sub-association Malloch 1971. A. maritima and Silene vulgaris ssp. maritima attain constancy in the grassier sward of this sub-community where H. lanatus and (especially) F. rubra tend to rival H. non-scripta in abundance. Cochlearia officinalis is differential and there are small amounts of other maritime species: C. danica, Beta vulgaris spp. maritima and Spergularia rupicola.

Ranunculus ficaria sub-community: Endymio-Armerietum maritimae, Ranunculus ficaria sub-association Malloch 1971. H. non-scripta is much more consistently dominant here though F. rubra, H. lanatus and Dactylis glomerata are all constant contributors to the sward. The most distinctive feature of the vegetation, however, is the constancy in small amounts of R. ficaria and the preferential occurrence of Heracleum sphondylium, Galium verum and Pteridium aquilinum and a variety of species characteristic of scrub and woodland: Brachypodium sylvaticum, Primula vulgaris, Viola riviniana, Hedera helix and Rubus fruticosus agg.

Habitat

The Festuca-Hyacinthoides community is most characteristic of situations where deep, moist and fertile brown soils develop under moderate maritime influence and it is usually found on gentle to moderate north-facing slopes or in deep gullies fairly high on cliffs.

Synonymy

Asteretum and Creek Asteretum Chapman 1934; Aster tripolium var. discoideus nodum Adam 1976; descriptions of Great Aster marsh, Scolt Head, Norfolk.

Constant species

Aster tripolium var. discoideus, Puccinellia maritima, Salicornia agg.

Rare species

Arthrocnemum perenne.

Physiognomy

The association is dominated by the rayless Aster tripolium var. discoideus which is especially distinctive in the late summer–early autumn flowering season when its stems may attain a height of about 1 m; at other times the vegetation is 10–20 cm tall. The stands are generally rather species-poor though there is usually some Salicornia agg., Puccinellia maritima and Suaeda maritima. The substrate surface is frequently dissected by small drainage runnels threading between the A. tripolium rootstocks and locally may be carpeted by free-living fucoids, mainly Fucus vesiculosus ecad caespitosus and Pelvetia canaliculata ecad libera.

Although there is a floristic gradation between lowlevel stands with abundant Salicornia agg. and those at higher levels with abundant Puccinellia maritima, no sensible subdivisions can be made within the association. The floristic disinctions catalogued by Chapman (1934) between a low-marsh Asteretum and a Creek Asteretum are not borne out in the samples.

Habitat

The association occurs as an extensive zone in the low marsh or on creek sides at varying levels in the marsh. At its lower limits, the association seems able to tolerate upwards of 500 submergences/year (Chapman 1960a) with a maximum development around 350 submergences/year (Clapham et al. 1942).

Synonymy

Hippophae rhamnoides scrub Tansley 1911; Hippophaëtum Tansley 1939; Hippophaë communities Pearson & Rogers 1962; Dune scrub Gimingham 1964a p.p.

Constant species

Hippophae rhamnoides.

Rare species

Hippophae rhamnoides.

Physiognomy

Hippophae rhamnoides occurs sparsely and at low cover in a variety of vegetation types of less mobile dune sands, but the Hippophae scrub includes stands where this thorny, deciduous shrub is becoming a consistent and more prominent feature. The density and height of the bushes is, however, very variable. At one extreme, the community includes grassier vegetation where the buckthorn is scattered and of only moderate cover overall, whereas other stands have a very thickly-set mass of suckering stems with a virtually impenetrable canopy of the stiff branches. Exceptionally, the bushes can attain over 3 m in height but 1–2 m is more usual and, in more exposed situations, the cover may be severely windtrimmed.

The extent and character of the associated flora is very much dependent on the degree of Hippophae dominance, and no other species are constant throughout the community. Interestingly, the most frequent dune grass overall is Elymus pycnanthus, but there is quite commonly some Poa pratensis and Holcus lanatus, with more occasional Agrostis stolonifera, Dactylis glomerata and Carex arenaria. The most widely distributed dicotyled on is Senecio jacobaea, with Cirsium arvense, Sonchus arvensis, Epilobium angustifolium and Heracleum sphondylium occurring more rarely but with local abundance. Rubus fruticosus agg. is also fairly frequent and can thicken up in places among and around the buckthorn.

Synonymy

Strand plants association Tansley 1911; Foreshore communities Tansley 1939; Salsola kali-Atriplex glabriuscula Association Tx. 1950; Atriplici-Polygonetum raii Tx. 1950; Cakile maritima-sociatie Boerboom 1960; Sociation à Salsola kali Géhu & Géhu 1969; Sociatie van Honkenya peploides Westhoff & den Held 1969; Honkenietum peploidis Géhu & Géhu 1969.

Constant species

Cakile maritima, Honkenya peploides.

Rare species

Polygonum oxyspermum ssp. raii.

Physiognomy

The Honkenya peploides-Cakile maritima community occurs as patchy strips of strandline vegetation in which Honkenya peploides, Cakile maritima and various Atriplex spp. are the most consistent elements. Honkenya is a perennial and low clumps of its succulent, creeping shoots can be a conspicuous feature here all the year round, being firmly anchored in the sandy gravel substrate, able to accumulate a little wind-blown sand and tolerant of the very occasional, brief inundations by seawater that come with extreme high tides and winter storms. Other characteristic species are more ephemeral, but they too can become abundant in summer, especially where organic detritus has been deposited along the tidal limit or incorporated beneath a shallow covering of beach material, and they may give a distinctive appearance to particular stretches of the community. Among these annuals, Cakile is very frequent and sometimes plentiful and there is usually one or other, or a mixture, of the common Atriplex spp. of strandline habitats, quite often in locally dense populations which have sometimes been treated as the basis of separate vegetation types (e.g. Birse 1980).

Synonymy

Epilobium hirsutum-Filipendula ulmaria community Wheeler 1980 p.p.

Constant species

Epilobium hirsutum, Urtica dioica.

Physiognomy

The Epilobium hirsutum community comprises often species-poor tall-herb vegetation in which E. hirsutum is a constant and generally very abundant feature. It is usually accompanied by Urtica dioica, overall a subordinate element in the cover but locally abundant in a patchy canopy of the two species that is often over 1 m tall. No other plants are frequent throughout but Filipendula ulmaria, Arrhenatherum elatius and Cirsium arvense are common in various of the sub-communities and occasional are Carex acutiformis, Phalaris arundinacea, Deschampsia cespitosa, Galium aparine and Rumex crispus. Patches of Calliergon cuspidatum and Brachythecium rutabulum are sometimes to be seen over the soil and stools.

Sub-communities

Juncus effusus-Ranunculus repens sub-community. E. hirsutum is overwhelmingly dominant here with only occasional and usually not very abundant U. dioica. Ranunculus repens is frequent, creeping among the willow-herb stools, and tussocks of Juncus effusus can be prominent. Occasionally, there is some Cardamine flexuosa, Angelica sylvestris, Mentha aquatica, Holcus lanatus, Poa trivialis and Deschampsia cespitosa.

Phragmites australis-Iris pseudacorus sub-community. E. hirsutum remains dominant in this sub-community but it is typically accompanied by patches of U. dioica and Phragmites, with scattered individuals of Iris pseudacorus, Filipendula ulmaria, Eupatorium cannabinum, Lythrum salicaria, Lycopus europaeus, Lysimachia vulgaris and sprawling Solanum dulcamara, Calystegia sepium and Galium palustre. More locally, Glyceria maxima, Carex riparia or C. paniculata can occur with some abundance.

Synonymy

Includes Trifolium occidentale-Herniaria ciliolata-Catapodium marinum and Trifolium occidentale-Scilla autumnalis-Jasione montana noda Coombe 1961; Sagino-Catapodietum marinae R. Tx. & Westhoff 1963; Thero-Sedetum anglici Malloch 1971; Sedion anglici communities Proctor 1975.

Constant species

Armeria maritima, Plantago coronopus, Festuca rubra, Cerastium diffusum ssp. diffusum, Sedum spp. (S. anglicum and S. acre).

Rare species

Allium schoenoprasum, Astragalus danicus, Brassica oleracea, Centaurium capitatum, Genista pilosa, Herniaria ciliolata, Lotus hispidus, Mibora minima, Minuartia verna, Ononis reclinata, Ornithopus pinnatus, Poa bulbosa, P. infirma, Polycarpon tetraphyllum, Romulea columnae, Scilla autumnalis, S. verna, Senecio integrifolius ssp. maritimus, Trifolium occidental, T. suffocatum.

Physiognomy

The Armeria-Cerastium community has a very short open turf in which cushions of A. maritima, tussocks of rather poorly-growing F. rubra, P. coronopus or Sedum spp. may dominate. Sprawling plants of C. diffusum ssp. diffusum occur throughout and the annual grasses Desmazeria marina and Bromus hordeaceus ssp. ferronii are frequent. Numerous winter annuals flourish on the patches of bare ground and many of these are national rarities. Trifolium spp. of restricted distribution are also characteristic of some sub-communities. Bryophytes occur at low frequencies throughout but in some sub-communities they and lichens may attain up to 20% cover.

Sub-communities

Desmazeria marina sub-community: Sagino-Catapodietum marinae R. Tx. & Westhoff 1963 p.p. In this, the most species-poor of the sub-communities, A. maritima and either F. rubra or D. marina tend to co-dominate with scattered plants of C. diffusum ssp. diffusum, B. hordeaceus ssp. ferronii and Spergularia rupicola.

Synonymy

Agropyretum pungentis Perraton 1953; includes Agropyron pungens-Juncus maritimus nodum Adam 1976.

Constant species

Elymus pycnanthus.

Physiognomy

The association is invariably dominated by the stiff clumps of Elymus pycnanthus and this may be the sole species. Usually, however, there are a few associates though these are somewhat varied and individual stands may be rendered distinctive by the abundance of (a) particular species. Sometimes there is a patchy or extensive understorey of Halimione portulacoides, Artemisia maritima and/or Puccinellia maritima. In other cases, Atriplex prostrata and/or Festuca rubra may be conspicuous. Juncus maritimus is sometimes abundant though stands with this species are not worthy of distinction as a subcommunity (cf. Adam 1976, 1977). Other stands have a prominent umbelliferous element with Conium maculatum, Foeniculum vulgare and Smyrnium olusatrum and, more locally, Petroselinum segetum and Sison amomum.

Habitat

The Atriplici-Elymetum is an upper-marsh community occurring on a variety of substrates including organicallyenriched clay, sand (where Festuca rubra is often abundant) and shingle. Substrates are generally well-drained and there is often considerable free calcium carbonate derived from inwashed shell fragments. The pH is generally above 7.0. The association also occurs on older, partly decayed drift litter, where Atriplex prostrata flourishes, but in many stands there is little litter except at the seaward edge.

The association may be confined to a narrow strip around the tidal limit or form extensive stands in the upper marsh; occasionally it forms mosaics with other communities.

Synonymy

Plantago sward Praeger 1911, Tansley, 1939, Asprey 1946, Poore & Robertson 1949, McVean 1961 p.p.; Plantaginetum coronopi Gillham 1953 p.p.; Plantago maritima nodum Malloch 1971; Habitat Group IV Goldsmith 1975 p.p.

Constant species

Festuca rubra, Plantago coronopus, P. lanceolata, P. maritima, Agrostis stolonifera.

Rare species

Astragalus danicus, Oxytropis halleri, Primula scotica, Scilla verna, Trifolium occidentale.

Physiognomy

The Festuca-Plantago maritime grassland has a closed, very short and tight sward which is generally dominated by F. rubra and Plantago spp., especially P. maritima, with some Agrostis stolonifera and a variety of diminutive herbaceous associates of which Euphrasia spp. (usually grazed beyond recognition to the species), Lotus corniculatus, Leontodon autumnalis, Cerastium fontanum and Scilla verna are the most frequent throughout. Bryophytes make a small contribution to the sward with occasional records for Hypnum cupressiforme and Mnium hornum.

Sub-communities

Armeria maritima sub-community: Plantago sward auct. angl. p.p. A. maritima is an additional constant in the rather species-poor sward of this sub-community, though it is only rarely abundant. Holcus lanatus, Cochlearia officinalis, Poa subcaerulea (especially in the north), Silene vulgaris ssp. maritima, Leontodon taraxacoides and Cerastium diffusum ssp. diffusum are preferential or differential at low frequency. Oxytropis halleri, Primula scotica and Trifolium occidentale occur occasionally within their ranges of distribution.

Carex panicea sub-community. Euphrasia spp., Lotus corniculatus and Leontodon autumnalis attain constancy in this more species-rich and rather variable sward but the really distinctive feature is the constancy and occasional abundance of Carex panicea.

In Britain, three species of eel-grass, Zostera marina, Z. angustifolia and Z. noltii, form distinctive stands in the sub-littoral and eu-littoral zones of sand and mud flats. Very few samples of this vegetation were taken and the following account relies heavily on published and unpublished material relating in particular to The Solent (C. R. & J. M. Tubbs), the Thames estuary and Essex (Wyer & Waters 1975; Charman 1975, 1977b, 1979), north Norfolk (Ranwell & Downing 1959, Charman & Macey 1978), Lindisfarne (D. O'Connor), the Moray Firth (Rae 1979), and the west coast of Scotland (A. Currie). There are two difficulties in making use of existing information. First, Z. angustifolia is not consistently distinguished from narrow-leaved forms of Z. marina: this partly reflects the long-standing discussion on the taxonomic status of plants variously described as Z. marina var. angustifolia, Z. hornemanniana or Z. angustifolia. Second, eu-littoral stands have often been described simply as ‘Zostera’ irrespective of whether they comprise Z. angustifolia, Z. noltii or both these species. This has been particularly true of accounts of the grazing of Zostera spp. by wildfowl and a separate note on this important aspect of the conservation value of the vegetation has therefore been appended.

Synonymy

Suaeda maritima nodum Adam 1976; Salicornietum auct. p.p.

Constant species

Suaeda maritima is a variable taxon within which a number of distinct forms have been recognised. These are sometimes treated as varieties (e.g. Chapman 1947, Clapham et al. 1962) or as species. Ball (1964) has a single sub-species S. maritima maritima to include all British material. This is the only constant taxon of the community.

Physiognomy

This is a species-poor community, generally open, though always dominated by Suaeda maritima the density of which is normally high. There is sometimes a little annual Salicornia, Puccinellia maritima, Spartina anglica, Halimione portulacoides and Aster tripolium var. discoideus. An algal mat is quite common and Chapman (1947) lists seven different algal assemblages associated with abundant Suaeda maritima.

Sub-communities

Variation within the community is continuous, though the predominance in particular stands of different forms of Suaeda maritima has been used by some (e.g. Géhu 1975) to assign such stands to different communities. However, diagnosis is often difficult and there seem to be few consistent ecological differences between the taxa.

Habitat

Suaeda maritima is an annual and it is tolerant of a wide range of soil types subject to various submersion regimes: Chapman (1947) reported it dominant on Norfolk marshes with between 290 and 430 submergences/year.

Synonymy

Agropyretum juncei Moss 1906, Tansley 1911, 1939; Agropyretum boreo-atlanticum (Warming 1909) Br.-Bl. & De Leeuw 1936; Elymo-Agropyretum junceiforme Tx. 1955; Agropyron junceiforme stands Gimingham 1964a; Elymo-Agropyretum boreo-atlanticum Tx. (1937) 1967; Sociation à Agropyron junceiforme Géhu & Géhu 1969.

Constant species

Elymus farctus ssp. boreali-atlanticus.

Rare species

Euphorbia paralias.

Physiognomy

The Elymus farctus community comprises generally open, though often locally dense, vegetation in stretches of wind-blown sand, in which the dominant is the perennial grass long familiar as Agropyron junceiforme, but now known as Elymus farctus ssp. boreali-atlanticus. It is a rhizomatous plant, growing in the early stages after colonisation as small rosettes of shoots, often appressed to the surface, but then spreading outwards by means of its long and wiry underground stems and putting up vertical sympodial branches which by repeated tillering can keep pace with rapid though quite modest accumulation of sand (Nicholson 1952). Young colonies of the grass often have little more than small, low domes of sand around them but, where accretion progresses, distinct dunes, sometimes 1 m or more high, can develop. The grass shoots grow 20–60 cm tall and may be closely massed where the plants are especially vigorous, the glaucous foliage contrasting sharply with the bright yellow of the mobile sand.

Synonymy

Juncus gerardii-Carex extensa Association Birks 1973 p.p.

Constant species

Blysmus rufus, Agrostis stolonifera, Glaux maritima, Juncus gerardii, Triglochin maritima.

Rare species

Blysmus rufus.

Physiognomy

The Blysmetum rufi is a species-poor association, generally dominated by Blysmus rufus but often with abundant Agrostis stolonifera, Glaux maritima and Juncus gerardii. Triglochin maritima, Festuca rubra, Plantago maritima and Carex extensa are all frequent but rarely present in quantity. Some stands may have an extensive algal mat and certain bryophytes may be abundant: Amblystegium riparium, A. serpens, Calliergon cuspidatum, Campylium stellatum, C. polygamum, Drepanocladus aduncus and Cratoneuron filicinum. Cover may be somewhat open, especially on gravelly or rocky substrates, and stands are usually small (10–20 m2), though at a number of Scottish sites the association covers hundreds of square metres.

Habitat

The association occurs on a variety of substrates but sites are often either poorly-drained or subject to flushing by brackish or fresh-water. The characteristic situation is in small depressions in the upper marsh. In some cases, the Blysmetum may develop in old upper-marsh pans, especially where these have a shingle base, and it is sometimes present along path edges (Gillner 1960, Tyler 1969b, Beeftink 1977a). In west Scotland, small stands are widespread within rocky flushes in the saltmarsh/mire transition on raised beaches and also among coastal rocks (Gillham 1957b, Birks 1973, Adam et al. (1977).