SShhrrooppsshhiirree BBoottaanniiccaall SSoocciieettyy NNeewwsslleetttteerr,, AAuuttuummnn 22001155 EEppiilloobbiiuumm mmoonnttaannuumm BBrrooaadd--lleeaavveedd WWiilllloowwhheerrbb sseeeedd ccaappssuullee ooppeenniinngg,, pphhoottoo MM..CCoouussiinnss,, 22001155 1 Shropshire Botanical Society Newsletter No.31 Contents Page Society Matters 3 Plant Records 2015 4 Botanical Change in Shropshire 5 Epilobium (Willowherbs) in Shropshire 9 Galeopsis angustifolia Red Hemp-nettle in Shropshire, just… 15 Ten Targets for Conservation in Shropshire - an Update 16 What is happening at Catherton Common 20 Plant Introductions at Llynclys Quarry 25 The Location of Cwm Floyd 29 List of Members (with renewal dates) 31 Contacts Newsletter Editor: Mags Cousins, email: [email protected] Secretary: Penny Wysome, 2 Christine Ave., Wellington, Telford, TF1 2DX. Tel. 01952 242617, email: [email protected] Membership Secretary: Position vacant Vice-county Recorder: Sarah Whild, 9 Albert Street, Shrewsbury, SY1 2HT. Email: [email protected] Past copies of the newsletter are available as pdfs from the Shropshire Botanical Society website: http://www.bsbi.org.uk/shropshire.html Any opinions expressed in this newsletter are those of the various authors, and are not necessarily those of the Society. Ordnance Survey maps reproduced under licence No. 100040428. Our thanks go to the Shropshire Wildlife Trust and the Field Studies Council for their generous support of our society. Both organisations support the work of the society in recognition of the importance of the contribution we make to understanding Shropshire botany. 2 Society Matters Mags Cousins If you were able to attend the launch of the Flora and Vegetation of Shropshire in March this year, you will know that it was the culmination of many years’ hard work and a great celebration. In this edition of the newsletter Ian Trueman gives an insight into some of the findings of the survey work carried out for producing the Flora, which makes for sobering reading but with some areas for optimism. We also have an update of the top ten targets for conservation in Shropshire, five years after these were first proposed; reports on establishing species at Llynclys Quarry; the status and ecology of the rare Galeopsis angustifolia Red Hemp- nettle in Shropshire; another view of the characterisation of the heathland at Catherton Common and a closer look at the difficult group Epilobium. If you still need to purchase your copy of the Flora and Vegetation of Shropshire or have Christmas presents in mind, please send your order at £35 per book to the Treasurer Sue Townsend email: [email protected], Tel. 07977 574980. You will be able to collect your copies at the Christmas meeting and thereby not incur the £4.40 postage charge, Prior purchase will also help the team plan the number of copies to bring on the day. Very many thanks to Mark Duffell who has stepped down from the role of Membership Secretary as, amongst other things, he is very busy teaching identification classes, as many of you will know from having attended his courses this year! So the committee need help with memberships, the role mostly involves receiving money from members, what's not to like?! For the time being payments can be sent to the Treasurer Sue Townsend, at No 4, Thatched Cottages, Shrawardine, SY4 1AE, see inside back cover for renewal dates of memberships. Winter Meeting, Saturday 12th December 2015, 2–4 pm. Come and join us for a festive social and a topical talk at our usual venue Preston Montford Field Studies Centre, Montford Bridge, Shrewsbury, SY4 1DX. Speaker Dr Jonathan Briggs: "The Mysteries of Mistletoe" Jonathan Briggs studied Botany at the University of Bristol and Industrial Archaeology at the Ironbridge campus of the University of Birmingham. He runs an ecological consultancy based in Gloucestershire with interests in parasitic plants, ecology of historic navigation canals, the ecology and conservation of unusual plant and insect species plus some industrial and landscape archaeology. Spring Meeting 2-4pm, Saturday 9th April 2016, also at our usual venue Preston Montford Field Studies Centre, Montford Bridge, Shrewsbury, SY4 1DX. Our very own Prof Ian Trueman will give a talk on "Changes in the Shropshire Flora since Sinker". 3 Plant Records 2015 Alex Lockton Not many exciting finds to report so far this year, which is what is to be expected when a new Flora comes out. Having said that, however, there is plenty of recording going on. Shropshire Wildlife Trust has been very energetic in surveying Wildlife Sites, which is great for getting lists for under-recorded areas, often with limited public access; and Paul Green has been working for SEDN recording in some of the less well-known South Shropshire Hills. We shall have as many records as ever, and they all contribute towards our aim of getting better coverage at the monad (1 km) scale. The other main source of data at the moment is historical. We have two complete Floras of the county to computerise – one by William Beckwith, compiled before his death in 1892, and one by Richard Benson and William Hamilton, compiled in about 1909. There are about 3,000 pages in these two documents, and each one takes a couple of hours to compile. The job is about 50% completed. When it is done it will give us a historical dataset for this county that appears to be unparalleled elsewhere. New records Malva arborea (L.) Webb & Berthel., Tree-mallow. Spotted by Mark Duffell in the central reservation of the A5 at Churncote, SJ4413, 25th March 2015. This is a first for the county. It is a bit tricky to photograph in situ, so here is a picture of it on Whitstable Beach. Malva arborea Vaccinium x intermedium Vaccinium x intermedium Ruthe (myrtillus x vitis-idaea), Hybrid Bilberry, has been known on the Stiperstones since 1968, when it was first recorded by Charles Sinker, ‘by the ridge path and at Manstone Rock’ (SJ370995). It was later refound by Kate Thorne, but doubt about its identity had been expressed by several people at a Recorders’ Conference, so we have been a bit uncertain about it since then. Now Kate has provided photographs which are confirmed by Clive Stace, ‘without any doubt,’ so we apologise to Kate for calling into question her original identification… It is recorded at SJ381011, SO356968 and SO366982. 4 Botanical Change in Shropshire Ian Trueman The publication of The Flora and Vegetation of Shropshire in 2015 allowed a comparison with the Ecological Flora of the Shropshire Region, published in 1985. This was attempted in the new Flora and I have been asked to distil out some of the main points here. There are some problems in making a direct comparison between the two Floras. We had to entirely omit the 200 ‘very common’ species which were not recorded to tetrad level in the 1985 Flora, also some particularly unevenly recorded microspecies. In the BSBI Atlas, changes in an individual species were assessed against the background of the average change in order to reduce the affect of different recorders. We noted that the size of the comparable databases in the two studies (63,326 tetrad records in 1985 and 64,241 in 2015) was very similar and we used the raw data throughout. It is fashionable to contrast the native flora with the anciently (archaeophyte) and more recently (neophyte) introduced floras. In Shropshire, all three types seem to be increasing in numbers of species as we get to know the flora better. However, a better impression of the overall frequency of the types is given if each species is multiplied by the number of tetrads in which it has been recorded. The total number of tetrad records of native tetrad records has decreased by about 4% between the two Floras, archaeophytes by 12% and neophytes have increased by 60%. Most of the archaeophytes are ancient weeds of cultivation and modern agriculture has largely defeated them. Even so, the archaeophytes Galeopsis angustifolia, Legousia hybrida and Ranunculus arvensis, all thought extinct here by 1985, have been rediscovered since 1985. I think that they will be difficult to eliminate altogether. Neophytes have been ‘invading’ Britain and Ireland since 1500 AD, but modern mobility seems to have increased this process tremendously. The list of neophytes which were rare or absent in Sinker’s Flora and are now common or even abundant is quite startling. The classical invasive aliens Fallopia japonica Japanese Knotweed and Impatiens glandulifera Indian Balsam were both pretty frequent by 1985 but are now joined by many other plants such as Acer platanoides Norway Maple, Buddleja davidii Butterfly-bush, Prunus laurocerasus Cherry Laurel, Cotoneaster species, Lamiastrum galeobdolon subsp. argentatum Variegated Yellow Archangel and Hyacinthoides x massartiana Hybrid Bluebell which were rare or absent or at least unrecorded in the 1985 Flora but are now all very frequently recorded. It is true that the modern botanist is more likely to record such plants than our more fastidious predecessors but most of them are now very familiar in rather disturbed communities, and a few even in more stable and characteristic communities! It is however possible to exaggerate the speed and extent of these trends. The flora is still overwhelmingly native (dropping from 78% to 74% of tetrad records between the two Floras; neophytes still only accounting for 14%) but the trends are clear. Species extinctions from the vice county continue, although not at an obviously accelerating pace, and going down the list of important native and archaeophyte species feared extinct in the last Rare Plants of Shropshire in 2005 it is somewhat heartening to think that Hippuris vulgaris Mare’s-tail, Cardamine impatiens Narrow-leaved Bitter-cress, Hordeum secalinum Meadow Barley, Limosella aquatica Mudwort, Potamogeton lucens Shining Pondweed, and Hymenophyllum wilsonii Wilson’s Filmy-fern have all been seen here since then. Most of the species which have ‘stayed extinct’, such as Carex limosa Bog-sedge, Sparganium natans Least Bur-reed, Baldellia ranunculoides Lesser Water-plantain, Drosera anglica Great Sundew and Drosera intermedia Oblong-leaved Sundew have been of plants long known from a single or a 5 very small numbers of lowland sites and many of these losses reflect the apparently inexorable eutrophication and inappropriate management of lowland, and especially wetland and open water, habitats. Nevertheless, in the Flora we were able to list 88 native species with a long history as members of recognised vegetation which have five or fewer tetrad records since 1985 and many of these vulnerable species have clearly decreased in frequency. One or two, such as Gentianella campestris Field Gentian, may already be extinct here. How long will it be before all these species are found at a single site? Most habitats are represented but open water, wetland and other non-wooded habitats predominate. Most of the 88 species listed are, not unexpectedly, axiophytes. Change in the frequency of axiophyte species is by definition going to be important in nature conservation terms and although a minority of axiophytes (150) show negative percentage changes in tetrad frequency between the two Floras this amounts to 3,055 less tetrads and those showing positive or no change (193) have only added 1,687 tetrads, so the trend in axiophyte richness is downwards. It is also probable that most of the increases are in detection rather than in propagation. Such species are usually lousy colonist, also almost by definition. Nevertheless not all the increases can be easily explained away and in particular big increases in Dactylorhiza praetermissa Southern Marsh-orchid, Empetrum nigrum Crowberry, Filago minima Small Cudweed, Ophrys apifera Bee Orchid, Origanum vulgare Marjoram, Orobanche rapum-genistae Greater Broomrape, and Ranunculus parviflorus Small-flowered Buttercup may have positive ecological explanations. Many relatively common, mostly non-axiophyte species show considerable change in tetrad numbers between the two Flora surveys. Some wetland and open water species such as Senecio aquaticus Marsh Ragwort, Ranunculus sceleratus Celery-leaved Buttercup and Alisma plantago-aquatica Water-plantain have over a hundred tetrads records fewer in the new Flora. Species predominantly associated with other types of predominantly non-wooded vegetation show similar huge losses. Top (or bottom!) scores go to Cruciata laevipes Crosswort which has 263 fewer tetrad records and Linaria vulgaris Common Toadflax with 200 fewer. A total of 39 species have over 100 tetrads fewer and a further 52 have over 50 fewer. This includes Primula veris Cowslip, Betonica officinalis Betony and Knautia arvensis Field Scabious, but also representatives of most habitat types including a few heathland species such as Calluna vulgaris Heather and Vaccinium myrtillus Bilberry. There are also large increases in equivalent numbers of species. Many of these, such as Epilobium obscurum Short-fruited Willowherb and Carex pilulifera Pill Sedge, are probably in part the result of better descriptions in the Floras (and the increased provision of biological recording courses!) but the overwhelming majority are neophytes or natives known to be escaping from garden cultivation. One possible exception from these explanations is Euonymus europaeus Spindle, native in our hedgerows and woodlands, which has 61 extra tetrad records. Much can be learned by attempting to analyse and map the plant data set as a whole. We used two main techniques to achieve this in the change chapter: coincidence mapping and multivariate analysis. We produced coincidence maps of the complete set of axiophyte species for the two floras, distinguishing between tetrads according to the number of axiophytes recorded. These maps show a very similar distribution and numbers in the two surveys, especially in the richer areas. The big changes are in the poorer areas. A much larger number of tetrads (643) have low scores of fewer than 20 axiophytes (541 in the old Flora) and a much smaller number (165) have modest numbers of 20-39 axiophytes in the new Flora (361 in the old Flora). These differences are significant statistically and also, we think, ecologically. The maps show a widespread reduction in tetrads with 20-39 axiophytes where they previously surrounded and linked the rich areas throughout the county, perhaps particularly in the south. 6 We also undertook and mapped a computer analysis of the complete data set - axiophytes and all the rest. This allowed us to divide the tetrads into types according to the species recorded in them and to map the types. Three main floristic zones were distinguished. Most distinct is the zone in which the tetrads are characterised by the significant presence of heathland species. This zone encompasses all our upland areas plus the acid-soiled parts of the Wyre Forest and the mosslands of the north. In the maps there are some small signs of contraction in the area of this zone since the 1985 Flora, especially in the Clun Forest, but the most obvious change is an increase in the most desirable types of tetrad within the zone, characterised by such plants as Eriophorum angustifolium Common Cottongrass and Drosera rotundifolia Round-leaved Sundew. Probably these areas are better recorded now but one big change since the early 1980s has been the amount of the uplands which are now managed for nature conservation. This may already be having a positive effect, for example where the relaxation of grazing pressure in the Long Mynd has revealed more diversity in the mires and grasslands. In the lowlands, the analysis separates two main types of tetrad. It distinguishes most of the landscape north of the River Severn which forms the Shropshire plain from the more dissected landscape with older geology south of the Severn and in the Welsh borders. The zone encompassing the intensively farmed North Shropshire Plain still includes many tetrads rich in the wetland species associated with the meres, rivers and canals of the region. There are signs of contraction in the number of these tetrads with rich wetland especially in the Whitchurch area, possibly mainly due to the loss of small fragments which were so enthusiastically drained and ‘improved’ in the 1970s and 1980s. The zone which comprises most of the south and central lowlands and also the lowland parts of the Welsh borders are largely characterised by the persistence of an ancient woodland flora. The richest grouping distinguished within this landscape zone is mainly associated with the core areas of the Oswestry and Wenlock limestones and this type is not strongly contracting in size. The rest show a strong trend between relatively species-poor tetrads and ones characterised by a wide range of species including Cruciata laevipes and many of the other species shown to be decreasing in our analysis of the individual species data. The complete list of species preferentially associated with this species-rich end of the trend is shown in appendix 4 of the change chapter. A wide range of species from most habitat types are included in this list, including some choice woodland species, but large numbers of the species are from a range of more open habitats, mostly on dry soils. Over half of them are axiophytes. This trend strongly differentiates between the two Floras – these richer tetrads were common in the 1985 Flora and are now quite rare. The maps of the ancient woodland landscape type show the Cruciata laevipes type abundantly surrounding the richest core areas and forming connections between them in the 1985 map, but largely eliminated in the 2015 map in parts of the south. Probably this deleterious trend between the two Floras reflects a general deterioration in diversity in ‘average’ tetrads, but many of the species which are becoming less common are found on road verges, hedgebanks and waysides generally. Cruciata laevipes is even characteristic of such marginal habitats where the vegetation is short and soils are modestly infertile. Many of the other species associated with this trend, such as Lathyrus linifolius Bitter- vetch (see photo below), Linaria vulgaris, Primula veris, Knautia arvensis, can often be found under similar conditions. The implication is that these marginal habitats are losing their diversity due to increases in soil fertility and neglect of management. As a result many develop vegetation dominated by a few tall herbs and grasses such as Anthriscus sylvestis Cow Parsley and Arrhenatherum elatius False Oat-grass, or are invaded by Brambles and tree seedlings, either way completely swamping the pre-existing diversity. We have all seen examples of this happening. 7 The implication of the species trends and the maps of the axiophyte analysis and the multivariate analysis are the same. We may have been modestly successful in protecting our best sites, although the threat remains, but the moderately rich ‘bits in between’, are continuing to deteriorate relentlessly. This process of fragmentation probably makes the richer areas more vulnerable in the long run. The solution proposed (for example by Sir John Lawton in his 2010 report to government) is landscape conservation. The Shropshire Flora data show how far we still have to go to recreate a more coherent, more continuous and hence much more resilient ‘ecological network’ or even just to stop its deterioration. We have to protect and nurture our core areas, but we must also have a mind to all the much more modestly rich linking areas in between our best sites. Apart from their value in landscape coherence, these waysides are where most of the public see botanical diversity and where I and doubtless many others were first struck by the beauty and complexity of our flora. As Charles Sinker said in the 1985 Flora, ‘we must not lightly let them go’. Roadside verge near Hobarris Wood, south Shropshire with Lathyrus linifolius Bitter-vetch, photo M.Cousins, 2015 8 Epilobium (Willowherbs) in Shropshire Mags Cousins The genus Epilobium is certainly not easy, needing careful attention to the full range of characters and ultimately verification from the county recorder and the referee for all but the commonest species. The plasticity of the true species and widespread hybridisation can cause problems in identification. Possibly the worst confusion arises when you think you have a hybrid but you don’t. Just because it is difficult to place a plant in a species does not mean it is a hybrid! Determining a true species means looking at the whole range of proven characters, in the case of Epilobium, especially the hairs. The indumentum (Latin, literally: "garment") is a covering of trichomes (fine "hairs") on a plant and entire keys have been devised for European Epilobium based on trichomes alone. The BSBI Plant Crib for Epilobium (Rich and Jermy 1998) stresses the importance of examining the quality of the indumentum. Looking at the whole range of characters, I have, for Shropshire Epilobium, compiled descriptions and details from keys already available. Others have produced their own keys or tables of characters to help sort out this genus, which are very helpful, such as the one for Hampshire Willowherbs (Rand, 2013) which includes just two that don’t occur in Shropshire. There are 10 species of Epilobium so far recorded in Shropshire and eleven hybrids (see Table 1). There are very few records of the hybrids (for records see SEDN and Lockton and Whild, 2015), mostly made or determined by G D Kitchener who is the BSBI (Botanical Society for Britain and Ireland) county recorder for Kent and referee for Willowherbs. His records were mainly in 2003 and mostly from the same few locations – Eaton Manor and Blists Hill in particular. No doubt there are many more to be found. I have not included hybrids here, again there are excellent accounts and keys, such as the BSBI Plant Crib (1998) and Sell and Murrell (2009). The characters (see Table 2) Epilobium have 4 sepals, 4 petals, 8 stamens, a single style and the stigma may be club shaped or 4 lobed according to which species. Five of Shropshire’s true species have clubbed stigmas and 5 have lobed ones, so if flowers are available this is a helpful character. Epilobium are perennial but this is not always obvious as even young plants can flower and in some species the flowering stems arise from leafy rosettes which were on last year’s stolons but these have long since withered. In this case, the plants only have insubstantial roots as if they were annuals, for example Epilobium palustre, Marsh Willowherb. The means by which the plants overwinter are known as the perennating structures and the presence, length, form and location of buds and rosettes on the stolons are all important characters. The shape of the stem – round or with four angles – is helpful, though in E. roseum two of the angles can be indistinct. 9 Hairiness is very important: the density of the covering; location eg upper or lower stem, leaf surface or veins; hairs spreading or appressed; glandular or not; even the length of the hairs. Leaf shape, the presence of teeth, the length of the leaf stalk if present and how the base of the leaf narrows or not are all important features. Flower size is helpful but variable, and colour too – whilst generally pink the white ones can help to pinpoint a species, eg E. roseum and E. ciliatum have flowers that start white and turn pink upon fertilisation. Species Status in Habitats Shropshire E. brunnescens New Neophyte, local, Prefers damp barish gd, woodland Zealand Willowherb increasing rides, flushes, streams South Shrops E. ciliatum American Neophyte, Waste gd, wetlands Willowherb widespread, increasing E. hirsutum Great Native, widespread, Common all wetlands except the most Willowherb stable acid, also riverbanks, waste gd, arable. E. montanum Broad-leaved Native, widespread, Woods, swamps, grassland Willowherb stable E. obscurum Short-fruited Native, widespread, Wetlands, wet wds, arable, waste gd Willowherb stable E. palustre Marsh Native axiophyte, Swamps and fens Willowherb local, decreasing E. parviflorum Hoary Native, widespread, Damp bare gd, arable fields, swamps, Willowherb stable pond margins, river bks E. roseum Pale Willowherb Native, scattered, Gardens, river bks, waste gd, walls stable E. tetragonum Square- Native, scattered, Wet wds, swamps, arable fields stalked Willowherb stable E. lanceolatum Spear- First record 2014 Likes dry sunny places, roadside in leaved Willowherb Shrewsbury Hybrid Parents Records in Shropshire Epilobium x aggregatum montanum x One record 1962 obscurum Epilobium x dacicum parviflorum x First record 1889 and in fields at Eaton obscurum Manor, 2003 Epilobium x floridulum parviflorum x Three records in 2003, Blists Hill, ciliatum Criftin Quarry and Eaton Manor Epilobium x interjectum montanum x ciliatum 1994 Pant, and 2003 Acton Scott and Church Stretton Epilobium x limosum parviflorum x One record 2003, Blists Hill montanum Epilobium x interjectum tetragonum x Two records 2003, Blists Hill and ciliatum Eaton Manor Epilobium x novae-civitatis hirsutum x ciliatum One record 2003, field margin Eaton 10