Dorset Flora Group

Resources

Events Programme 2010

Green winged orchid - Orchis morio
Green winged orchid
Orchis morio
Photo: Mark Heighes

All meetings begin at 10.30am and end about 4pm unless stated otherwise. Details of the planned sedge identification course and the group’s first fungi foray will be circulated later. All meetings in 2010 are joint with the Dorset Natural History and Archaeology Society. All are welcome; our leaders will be pleased to help inexperienced wildflower enthusiasts with identification skills. Numbers on some trips are limited; if you plan to attend please contact the leader. Please include a telephone number in case of overbooking and weather problems. If you require a written confirmation please enclose S.A.E. We ask that members do not bring their dogs to the meetings.

Queen’s Copse:
Saturday 24th April. Leader: Peter Hatherley.
Meet opposite Holt Wood SU033058. We aim to see Small-leaved Lime and Spurge Laurel in this Forestry Commission wood and hope to re-find an earlier record of Carex strigosa, thin spiked wood-sedge.

Stoborough Heath (Stocks Wood):
Saturday 15th May
Meet on Grange Road in a lay-by south of the railway bridge SY919847. At this meeting we aim to visit Dorset’s best site for Viola lactea, Pale Heath Violet, which is considered nationally threatened. This is part of the BSBI’s national threatened plant recording scheme. We will then ask members to visit a number of other sites on the Dorset heaths to search for this plant.

Dorset Wildflower Week:
Saturday 29th May – Sunday 6th June.
The full events programme is listed below.

Beacon Hill:
Saturday 12th June. Leaders: Robin Walls and Jon Crewe.
An introduction to identifying Common grasses. Booking essential through Dorset Environmental Records Centre 01305 225081. There is a charge of £10 (Non members £20). Cheques payable to DERC please.

Batcombe Down:
Saturday 26th June. Leaders: Robin Walls and John Newbould.
Meet in the car park on the side of Gore Hill, ST636039. This SSSI site has an interesting mix of chalk downland, scrub and acid chalk heath, formerly much more extensive in this area. We will be searching for Herminium monorchis, musk orchid, in its only Dorset site, but expect other interesting aspects of the flora to be found as the day progresses.

Godlingston Heath - Bog Orchid survey:
Wednesday 7th - Friday 9th July and Monday 12th - Thurrsday 15th July. Leader: Ted Pratt.
Meet at Dean Hill mini car park SZ017819. This is a joint venture between the National Trust and the Flora Group; it will take place over a number of days, weather permitting. Experience has shown that we need about eight people each day, so booking is essential. Book for as many days as you can commit - to Ted on 01929 427299. We hope to confirm the status of this site as one of the finest locations for Bog Orchid in the country. Wellingtons essential. Walking stick helpful. Please say if you can bring a GPS navigator -we need as many as possible.

Wild Plants of the Dorset Chalk, Lyscombe Farm:
Saturday 17th July at 12 noon. Leaders: Sean Cooch and Jonathan Cox , Natural England.
Chalk grassland, small woods, butterflies and fine views. Meet at the entrance to the track that leads to Lyscombe Farm from Drake’s Lane, between Cheselbourne and Piddletrenthide, grid ref. ST732004. There is an open area where cars may be parked. Bring footwear suitable for rough ground and steep slopes, and a packed lunch if required. Ticks may occur at this site. Please book beforehand with Natural England (01300 060 4812).

Wareham Common:
Saturday 14th August 10.30 – 12. 45. Leader: Ted Pratt.
This is a training meeting where beginners and improvers can get some help with Wetland plants. Meet outside Wareham hospital, SY918874 and please bring Wellingtons.

Marsh Gentians at Holt Heath:
Saturday 28th August. Leader: Robin Walls.
The group will attempt to re-survey known sites for Marsh Gentian on this National Nature Reserve. Grayling butterfly and heathland birds should also be seen and we will record the flora of the site as we go. If time permits we hope to look at Fallopia dumetorum, Copse Bindweed, in its only extant Dorset site nearby.

Wildflower Week

Dorset Flora Group field trip 2009

All walks are suitable for children unless marked ***.

Children under 14 welcome if accompanied and supervised by an adult. Walks are free of charge except Durlston on 30th May (£3) and Steamer Point on 5th June (£2); you may be invited to make a voluntary donation on others.

Stanpit Marsh:
Saturday 29th May at 2.30pm. Leader: Tim Wilkins.
01722 342746 or 07736 073463
Park at SZ172925 (free car park), 50 yards past the Ship in Distress pub. Please note that this is a popular site and the car park often fills up – other parking may be a short walk away.
Coastal salt marsh and acid grassland flora and many birds.

Eggardon Hill:
Sunday 30th May at 10.30am. Leader: Peter Cramb.
01308 488019
Park at Shatcombe lane picnic area (free car park) SY549948.
Flowers of chalk grassland on an Iron Age hillfort; attractive views.

Durlston Country Park:
Sunday 30th May at 2.30pm. Leader: Ted Pratt.
To book, phone Durlston Country Park 01929 424443
Meet at Durlston Visitor Centre at SZ031773 (car park charge).
Superb hay meadows.

*** Ringstead Bay:
Monday 31st May at 10.30am. Leader: John Newbould.
To book, phone 01305 837384
Maximum 10.
Ringstead Estate National Trust. Meet in the NT car park at its eastern end SY760823. Access is via Upton from the A353.
This is a cliff top walk to White Nothe. The path is narrow and numbers are limited to ten.

Bracketts Coppice – DWT nature reserve:
Monday 31st May at 2.30pm. Leader: Tony Bates.
To book, phone DERC 01305 225081
Grid ref. ST514074. Gate entrance and small car park on S. side of minor road, 2 miles due N of Corscombe and 3 miles W of Halstock.

Powerstock Common Flower Walk:
Tuesday 1st June at 2.30pm. Leader: Brian Godfrey.
To book, phone 01300 320833 or email brian@rowanstp41.fsnet.co.uk
Please book no later than Tuesday 25th May 2010.
Maximum 20. Not suitable for wheelchairs.
Meeting at Powerstock Common car park Grid ref SY546974. From the A356 follow the road to Toller Porcorum. Continue through the village towards Bridport. At the ‘T’ junction (about 1 mile beyond Toller), turn right. Follow the road downhill and the car park is just before the old railway bridge.
Powerstock Common is a former hunting forest now managed by the Dorset Wildlife Trust and has a variety of habitats harbouring a wide range of plant life.

Corfe Common:
Wednesday 2nd June at 2.30pm. Leader: Ted Pratt.
To book, phone 01929 427229
Maximum 20.
Meet at West Street car park SY958818 (car park charge). Wilts and Dorset bus no.40 (Poole-Wareham-Swanage).
Dry and wet ancient common with many species. Wellingtons needed for parts.

Radipole:
Thursday 3rd June at 10.30am. Leader: Nick Tomlinson.
To book, phone RSPB Radipole Lake Visitor 01305 778313; any member of staff can put bookings into the walks diary
Maximum 20.
Flat, wide paths, suitable for wheelchair users, pushchairs.

Kinson Common (SSSI and Local Nature Reserve):
Thursday 3rd June at 2.30pm. Leader: Mike Downing, Bournemouth Natural Science Society.
To book, phone 01202 698840
Not suitable for wheelchairs.
Meet at Kinson Swimming Pool Car Park on South Kinson Road at SZ069957.
A two hour walk through a mixture of habitats including dry and wet heathland. This reserve supports a large range of interesting plants. Sturdy footwear required and Wellingtons if wet.

Purbeck Wares:
Friday 4th June at 10.30am. Leader: Angela Peters, National Trust.
NT Purbeck Estate Office: 01929 450259
2 hours. Some steep slopes.
Meet at the car park by Langton House, at SY 998783.
Come and see some limestone grassland specialities with a backdrop of breathtaking coastal scenery, on this National Trust owned piece of coast.

Sutton Poyntz:
Friday 4th June at 2.30pm. Leader: John Newbould.
01305 837384 or 07703 565314 or email john_newbould@btinternet.com
The Sutton Poyntz waterworks is located at SY706839. The village is served by First Buses route 4B but the times vary. There is a large car park. Sutton Poyntz is best accessed from the Weymouth - Wareham Coast Road (A353) turning into Sutton Poyntz at the Spice Ship. Follow the brown tourist signs for the Springhead. Alternately, use the narrow C class road from Came Down, turning left by the red telephone box.

Hambledon Hill NNR:
Saturday 5th June at 10.30am. Leader: Andrew Branson.
01747 838223
Fine Chalk grassland flora in a fascinating site.

Steamer Point Local Nature Reserve:
Saturday 5th June at 10.30am. Leader: David Leadbetter on behalf of Christchurch Countryside Service.
To book, phone Steamer Point Nature Reserve 01425 272479
Maximum 20.
Meet at Steamer Point information centre, end of Seaway Avenue, Christchurch SZ197929 (car park charge) or bus route X12 Bournemouth – Lymington
A mix of woodland, cliff top grassland and shore species.

Portland Bill:
Sunday 6th June, 10.30am – 1.00pm. Leader: Bryan Edwards.
To book, phone DERC 01305 225081 (07779 695101 on the day)
Walking will mainly be on flat ground, but will be uneven and rocky in places.
Meet outside the Lighthouse Visitor Centre at the Bill (car park charge), where there is plenty of parking.

Abbotsbury Beach:
Sunday 6th June, 2.30pm. Leader: Jonathan Cox.
To book, phone Natural England 01929 557456
Meet at Abbotsbury Beach car park, SY 560846 (car park charge).
Shingle and coastal plants, including uncommon species. Sturdy footwear required.

Juniper Days

An introduction to the Plantlife Lowland Juniper Project

Cherhill, Calstone Wilts
Photo: Jon Crewe

Plantlife International, the wild plant conservation charity, has been investigating the reasons for the decline of Juniper, one of our three native conifers, for over a decade. Concerns for the well being of this plant were noted as long ago as the 1960’s when Lena Ward and Alistair Fitter, among others, began to survey existing populations. In the south of England these were mainly confined to the chalk, where stands of thousands sometimes occurred. A few isolated populations occurred on the heaths, particularly in the New Forest although in the North and Scotland the plant frequently haunts moorland. This note describes some of the southern populations which I visited this summer while on contract to Plantlife; we hope that a more detailed account of the whole project will follow in the future.

Southern populations of the typical sub-species, Juniperus communis communis, are found from Sussex to Gloucestershire and North to Buckinghamshire, with outliers in Kent and Cornwall, whereas sub species hemisphaerica is found only on the Lizard peninsula. One of my first Juniper trips was a visit to the spectacular downland slopes of Devil’s Dyke, near Brighton. Arriving early, I had time to explore alone and quickly found two fine bushes. I also had an early experience of the health and safety hazards of the job! Juniper seems to prefer steep slopes – mostly very steep. One does not so much walk up to a juniper bush as climb, scramble and slither. Great care must be taken to resist the temptation to cling to the juniper itself for security – branches can be broken off quite easily and this does not sit well with the best conservation intentions! After surviving the scramble down the hill I met with Charlie Caine, the NT Head Warden for the area and followed him to another nearby site. Charlie is a fell runner among many other talents, and following his long strides up the side of Devil’s Dyke requires rather more fitness than I possess; suffice to say that I took a long time over some vital photos while my breath returned.

Another difficulty arose at this site, in that I learnt of the existence of a book that claimed that the Junipers here had been planted by Brighton Council in the 1960’s. Plantlife aims to conserve naturally occuring native species, and this discovery cast doubt on the status of the Devil’s Dyke bushes.

More research required to check the origin of these bushes, if the suggestion was true, and an early pointer to the fact that this was not going to be the most straightforward of jobs.

An even greater demand on my fitness and agility came in Gloucestershire where I had to walk up Cooper’s Hill, site of the famous Cheese rolling contest. Those who choose to run down this hill have my utmost respect! The single remaining tree at this site is in fair health but tucked away in a shaded position to one side. Elsewhere in Gloucestershire some good stands of Juniper remain, particularly on Rodborough and Minchinhampton Commons. Seeing these superb limestone grassland sites in September made me determined to return in the summer to see the full range of flowers, which includes musk, frog and bee among 13 species of orchid, pasque flower and abundant clustered bellflower. Juniper seedlings seen on two sites here were sadly among the very few seen in visits to more than 20 sites across the south.

Local sites for Juniper are unfortunately lacking; it would not appear to have ever been a common plant in Dorset, and as far as we know is now represented only by a single plant on Compton Down. This bush is quite small and of unknown origin; it could be bird sown, but there is often a question mark against such isolated plants. The species has been planted in various locations over the years, sometimes by local volunteers concerned about dying bushes on their favourite patch and also by local councils with a conservation agenda. There are substantial plantings on St Catherine’s Hill near Winchester, known to be from local stock, but the origins of the more noticeable plantings on the M3 cutting are less well established. The aim of the Plantlife project is to preserve native stock; regrettably this has not always been a clear objective of landscape planting schemes.

The work directed by Julia Carey for Bucks County Council at a site named Grangelands probably exemplifies the necessary approach. The management team has already achieved success here with the use of exclosures in which numerous seedlings have appeared. The follow on work from this is to test natural establishment on bare ground, and some scrapes have already been created, ready for seed to be scattered. I look forward to returning here to investigate the success of this work; the site has excellent chalk grassland and a large population of the attractive Roman snail, judging by the numerous shells that litter the grassland. One of the best aspects of visiting Juniper sites is that those bushes that remain seem to have chosen their refuges at least in part for the views; a sunny day in Buckinghamshire, surrounded by orchids, bellflowers and quaking grass while Red Kites slowly pass overhead has much to recommend it.

Jon Crewe

2009 Field Trips

2009 Field Trip reports

Many thanks to John Newbould for providing these interesting and informative accounts of our days out.

April 25th, 2009
Shermel Gate to Rushmore Golf Course
This meeting being a joint meeting of the Dorset Flora Group and the Dorset County Boundary Group was very much in the nature of unfinished business from the field meeting of 2008. The first sector of woodland known as Foxbury Lower Hedge was reported in 2008, but the slightly later date allows us to report some ground flora species not noted in 2008. Toothwort (Lathraea squamaria) was quite common being parasitic on Hazel. In addition, Archangel and Early Purple Orchid (Orchis mascula) were present along the boundary. To the west, where the Longcroft Road forms a north-south divide the nature of the ground flora alters with Bracken, Bluebell and Yorkshire Fog being dominant in an English Oak Silver Birch woodland. Here Ted Pratt and Robin Walls identified the Lady’s Mantle Alchemilla filicormis subsp. vestita.
Walking west along the boundary through Chase Woods, there is a current management policy of keeping deer to selected areas using deer fencing together with clearing understory and doing coppicing. From the Longworth Road the ride north of Great Shaftesbury Copse is quite wide and although Bracken is present there is an interesting ground flora. This included Adder’s Tongue Fern (Ophioglossum vulgatum). This tiny fern (although recorded in old grassland and on woodland rides across Dorset (Bowen, 2002) is easily overlooked. Ted Pratt and Robin Walls were kept busy with Southern Woodrush (Luzula fosteri) and Hairy Woodrush (L. pilosa). Were we missing the scarcer hybrid? The view was we did not. Ted Pratt found Common Twayblade (Listeria ovata) and John Newbould found spikes of Greater Butterfly Orchid (Platanthera chlorantha). Pignut (Conopodium majus), Tormentil (Potentilla erecta) and Wood Sorrel (Oxalis acetosella) were an occasional find. The more acidic nature of the soil meant that Rowan (Sorbus aucuparia) saplings were present in the Beech plantation to the north.
We crossed the Bridmore Ride, where in the autumn of 2007 we observed the large Beech avenue being felled. These trees have now been replaced by new Beech with the saplings protected by wrought iron fencing indicating the owners wish to see the magnificent old trees replaced. Here Wood Anemone (Anemone nemorosa) and Town Hall-clock (Adoxa moschatel) were observed in the Beech and Hornbeam Plantation. Crossing Oxford Street into Monk Arundel Coppice, we once again encounted more acidic soils with Pedunculate Oak, Ash and Silver Birch in the woodland with Scaly Male Fern (Dryopteris affinis) and Bracken part of the less species rich ground flora. On finding the Golf Course, we retraced our steps.

May 16th 2009
Ackling Dyke and Harley Wood Leader John Winterbottom.
In quite strong winds, just five people turned up for this interesting meeting. Initially we walked south along Ackling Dyke with Down Farm on our west side. In recent years, partly by introduction and partly naturally, this section of Ackling Dyke has become wooded and enclosed. At the start of our walk, part of the bank was exposed revealing that its construction was based on quite large flints with earth. Although the wooded area is mainly on chalk, Field Maple was quite scarce but Sycamore and Ash were common. Beech has been introduced on the east side together with the occasional Yew (Taxus baccata). Of particular interest under the Beech were a number of spikes of White Helleborine (Cephalanthera damasonium) and near Harley Gap two spikes of Bird’s-nest Orchid (Neottia nidus-avis) were present. This orchid requires deep humus and often may not be found in the same place subsequently. There is a record from Harley Wood in the Dorset Rare and Scarce Plant Register dated 1991.
At Harley Gap, we walked west a short distance along the public footpath to see Field Mouse-ear (Cerastium arvense). John Winterbottom felt that this plant is increasing at this site, which Bowen (2002) maps mainly in this north-east area of Dorset along track sides. The intermittent hedge contained Buckthorn (Rhamnus cathartica) and Spindle (Euonymus europaeus). The seed heads of Common Knapweed (Centaurea nigra), also seen here, contained the gall Urophora jaceana.
We returned to Harley Gap to walk south east along the south side of Harley Down enabling us to survey Harley Wood to the south. Once again, we were surveying Ash-Field Maple-Dog’s Mercury woodland interspersed with areas of Beech Plantation and Hazel Coppice. Here the most interesting area was an area of the NVC W25 Bracken-Bramble scrub with a Bluebell and Yorkshire Fog dominated ground flora. Growing amongst large areas of Greater Stitchwort (Stellaria holostea) was a square metre patch of Meadow Saxifrage (Saxifraga granulata) re-finding a 1994 record of G.F. Field (Edwards and Pearman, 2004). Interestingly, this area proved to be the best for bird song with Chiffchaff, Robin, Great Tit and Chaffinch noted. A pair of Buzzard hawked Harley Down as we had lunch. Skylark was present on Wyke Down as we returned to the car.

June 20th, 2009
Tadnoll DWT Nature Reserve Leader Karen Banks.
The party set off at a brisk pace to climb Old Knowle in order to get a higher view of the survey area. A small area of Fox and Cubs proved to be Pilosella auranticum ssp. campaathicola. Much of the northern area is above 25m AOD and is typical Dorset heath with heather based - plant communities, together with associated species. Typically these are not species rich but on warm days in habitats specially created to be devoid of vegetation basking areas for the Reserve’s six species of reptiles have been provided. It is however, in the low-lying areas of the Reserve that many of the interesting plants area found.
We were asked to assist in up-grading the mapping of the rarer species. We soon found White-beaked Sedge (Rhynchospora alba), nearby Sundew (Drosera rotundifolia) and Slender St. John’s-wort (Hypericum pulchrum). A single bush (in flower) caused a moments pause for thought but was quickly identified as Alder Buckthorn (Frangula alnus) before surveying a small ochreous dyke, which drains Galton Heath to the west. Here the dry heath had become wet with Bog Myrtle (Myrica gale) and water plants such as Water Plantain (Alisma plantago-aquatica), Water Chickweed (Myosoton aquaticum), Bog Pondweed (Potamogeton polygonifolius) and Tussock Sedge (Carex paniculata).
Following lunch, the party moved to the valley floor to survey the water meadows, passing en-route nine large plants of Royal Fern (Osmundia regalis) located on an old field boundary. These water meadows are of exceptional quality managed by light grazing with cattle. The sward height is around 300mm, with few coarse herbs, no scrub and a herb and small sedge cover >30%. In addition, the meadows contain a number of plants scarce in Dorset e.g. Greater Burnet (Sanguisorbia officinalis), Meadow Thistle (Cirsium dissectum), Marsh Cinquefoil (Potentilla palustris), Marsh Speedwell (Veronica scutellata) and at least ten species of sedge including a ditch dominated by Slender Sedge (Carex lasiocarpa).
During the day, Jon Crewe reported Hobby over the Prison Farm fields, Yellowhammer was calling during lunch and there were numerous Chiffchaff. It was a poor day for Butterflies with just small numbers of seven species including: Small Skipper, Silver-studded Blue on the heath, and a single Small Heath in the water meadows. We also saw a number of Banded-Demoselle (Calopteryx splendens) and a single Small Red-damselfly (Ceriagrion tenellum).

July 11th, 2009
Godlingston Heath NNR Leader Ted Pratt.
Some twenty members of the Dorset Flora Group arrived in the Ulwell lay-by, before transferring into a smaller number of cars to survey Godlingston Heath for Bog Orchid (Hammarbya paludosa). We had assembled in driving rain, one week earlier than in 2008 with the objective of searching the mire where we had located around 30 spikes. The initial plan was to start at the Golf Club end and work northwards in a line counting the orchids and using GPS meters to note the locations. However, we decided to start at the point where the orchids had been located in 2008. The result after surveying about one tenth of the mire was an impressive 116 flowering spikes. Generally the orchids were found in a Black Bog Brush mire in 25mm of water associated with White-beaked Sedge (Rhynocarpus alba) and Bog Pondweed (Potamogeton polygonifolius). Bog Orchid has a mainly Atlantic coast distribution, with a single site in Norfolk, sites in the New Forest and our Dorset plants representing the east coast lowland heathland (Preston et. al. (2002). The plant needs plenty of light and moisture, low nitrogen levels and reaction value of 1 (Hill et. al. 2004). Robin Walls commented that although the orchid was found in around 25mm of water the general water level of the mire is around 250mm at the bottom of the Schoenus tussocks, with a pH of around 4.5.
Earlier in the morning, we were shown all three British sundews together with both hybrids all within a radius of 20m. In spite of the rain, Mr J. Cox spotted a single Purple-bordered Gold moth. We also saw a single Keeled Skimmer (Orthetrum coerulescens).

August 1st, 2009
Hartland Moor NNR Leader Ted Pratt.
Once again, members of the Dorset Flora Group impressively turned out in Wellingtons and waterproofs to search for Marsh Fern (Thelypteris palustris). Bowen (2004) provides a list of historical sites, but credit for this extant location goes to members of the British Pteredological Society who visited the area in 2008. However, at least 250m of the fen are still to be searched. It is a perennial fern of fen carr or open woodland requiring permanently wet conditions, light and low nitrogen favouring a reaction value of 6 (Hill et. al. (2004). Its stronghold in Britain is the Norfolk Broads (Preston et. al. 2002). In addition to Marsh Fern, we were shown Narrow Buckler-fern (Dryopteris carthusiana_ and looked for the hybrid D. carthusiana x dilatata without success. Robin Walls comments that: “the Narrow Buckler-fern is a plant of wet shady places in southern Britain, especially carr in our area. It is fairly frequent in this habitat on the Tertiary sediments of the Hampshire basin. It is also found further west extending into Devon.”
Another speciality of Hartland Moor the Dorset Heath (Erica ciliaris) was seen and nearby we were shown its hybrid with Cross-leaved Heath (E.tetralix) whose scientific name is Erica x watsonii. Other heathland specialists included a single Marsh Gentian (Gentian pneumonanthe) and White-beaked Sedge. In the very wet conditions few birds were flying but Green Woodpecker was heard calling and a single Silver-studded Blue butterfly made a bedraggled appearance together with a Slow-worm. Robert Aqulina collected some 20 invertebrates in the Pillwort pond including the notable scavenger beetle Hydrochus angustatus. Plant galls were recorded and reported elsewhere.

I am indebted to Ted Pratt and Robin Walls for reading through the report and drawing my attention to errors and adding important comments. An archival copy of the records associated with this report has been deposited at Dorset Environmental Records Centre.

John Newbould

Asher, J., Warren, M., Fox, R., Harding, P., Jeffcoat, G. & J. (2001) The Millennium Atlas of Butterflies in Britain and Ireland Oxford University Press, Oxford
Bowen, H.J.M. (2000) The Flora of Dorset Pisces Publications, Newbury
Edwards, B. and Pearman, D.A. (2004) Dorset Rare Plan Register DERC, Dorchester
Grime, J.P., Hodgson, J.G. and Hunt, R. (2007) Comparative Plant Ecology Castlepoint Press, Dalbeatie
Hill, M.O., Preston.C.D. and Roy, D.B. (2004) Plantatt – Attributes of British and Irish Plants: Centre for Ecology and Hydrology, Abbotts Ripton
Preston, C.D., Pearman, D.A. and Dines, T.D. (2002) The New Atlas of the British and Irish Flora Oxford University Press, Oxford
Rodwell, J.S. ed. (1991) British Plant Communities I. Woodlands and Scrub. Cambridge University Press, Cambridge
Rodwell, J.S. ed. (1992) British Plant Communities III. Grasslands and montane communities Cambridge University Press, Cambridge

Projects For 2010

Threatened Plant Project (TPP)
Many of you will know about the TPP, if you do, skip the remainder of this paragraph. The BSBI began the project two years ago with a view to getting a better national picture of our scarce plants. Each year they have chosen ten species and then a random selection of known sites for the species. They asked the recorders to visit the chosen sites within their vice-county and report on the size of the populations, the associated species, etc. If there is time we are encouraged to survey all known sites without a recent record. Most vice-county recorders (vcr) have involved other botanists and this is obviously sensible, so I would like to invite DFG members to join in this year.

The BSBI have published the species, but not yet sent me the sites we need to search in Dorset. However, with one exception, I am hoping we can visit all the sites. Only six of the species occur in Dorset:

Chrysanthemum segetum Corn Marigold
Herminium monorchis Musk Orchid
Hordeum marinum Sea Barley
Juniperus communis Juniper
Melittis melissophyllum Bastard Balm
Viola lactea Pale Dog-violet

The first one is widespread, as we found out last year doing the arable survey for FWAG, and it has wildly varying populations. So we will probably not manage a complete census. Juniper has been the subject of recent study (see Jon’s paper). The remainder are in very few sites; subject to access permission, we should be able to visit them all and search for new sites. In the programme you will see we plan a trip to find the pale dog violet. This is not an easy plant to identify and hybrids are known with other violets. Once we have sorted out these problems and got our eye in, I’m hoping we can reliably record the remaining sites during its flowering season. Later in the year we plan to go to the one site for musk orchid. It has not been recorded there for a few years, so an exhaustive search is well worthwhile. No prizes have been offered for finding it yet, but there is consolation for failure; the hillside has many other calcicolous grassland delights to enjoy. All we need now is warm sunny weather.

Dorset Rare Plant Register search list
DERC in conjunction with the BSBI published the hard copy in 2004, written by Bryan Edwards and David Pearman.

Ever since Bryan has kept a list of the older records and encouraged us to visit the sites and confirm the plants are still there. As the new vcr it falls to me to take on the responsibility of updating the DRPR at some time. Last year’s list has been updated with all the records I know about and is available from me or DERC as a spreadsheet, or of course, we can print it out when needed.

I have removed the sites that have been refound or been proved to no longer hold the species, but the ‘searched and not found’ sites are still there, with a date and name of the searcher. Ultimately we will probably have to conclude the species has been extirpated, but I’ve not yet thought of the rules for doing that – the ghost orchid story is a salutary lesson. I have added a few extra sites which would be worth searching for a variety of reasons. Please send records to me as soon as possible; the sooner I can update the list, the lower the risk of duplicating effort. We are exploring ways of making the search list available live.

Long-stalked yellow sedge (Carex viridula ssp. brachyrrhyncha)
This is a scarce plant in southern England and a nice plant to find in a fen. The Dorset RPR lists five sites and mentions others that have been rejected. Few have been visited recently and it would be nice to check up on its distribution and how well the populations are doing. There is a problem in that the closely related yellow sedge (Carex viridula ssp. oedocarpa) is common and can look very similar. Most of the time it is a small sedge with slightly curved stems found in acid habitats that can be relatively dry. Although not mentioned in the floras, it can grow more upright and to well within the range of C.v.brachyrrhyncha. Unfortunately this habit is more frequent in circum-neutral mires and flushes, leading to a potential mis-identification.

If anyone finds a C.v.brachyrrhyncha I would like to have a voucher specimen to deposit in the Dorchester herbarium (if the population is too small, I will come and see it in situ). One of the characteristics is the down-turned beak, a feature not easily seen in pressed specimens. Please collect a complete stem with leaves and fruiting head (not roots) and a vegetative shoot and send them to me fresh in a polyethylene bag, so long as this can be done within a few days. Otherwise it would be safer to press the specimen.

Incidentally, we are hoping to revive the herbarium in the museum. Peter and Margaret Cramb have been diligently working their way through Mansell-Pleydell’s herbarium for some time. There is a box of Humphrey Bowen’s unmounted material and we are hoping to acquire Prof. Good’s herbarium, which will also need mounting. All we need is the time, the space and most of all, money to buy acid-free herbarium sheets.

Brome grasses (Bromus sp.)
Another group of plants where I would like to see specimens is the smaller Bromus species. Soft brome (Bromus hordeaceus) has a number of subspecies. The very common hordeaceus is not of interest, but it can vary enormously in size. Particularly confusing are the small plants with a single spikelet that grow on dry, sandy soils, often near the sea. They can be mistaken for the scarcer subspecies: feronii, thominei, divaricus, or longipedicellatus. Slender soft-brome (Bromus lepidus) is a closely related species that can be difficult to distinguish. I suspect all of these are under-recorded and often misidentified. The new grasses handbook (T. Cope & A.Gray, BSBI, 2009) has some very useful pointers to identifying these taxa and clear drawings.

Other searches
One of the TPP species from last year was the frog orchid (Coeloglossum viride). This I failed to find at the specified site (I was a little late in the season) and talking with other botanists I wonder whether this orchid is less common than we think. Another plant that cropped up in the conversation was bastard toadflax (Thesium humifusum), aka the more descriptive ‘stars-in-grass’. Both occur in similar habitat and invariably with plenty of other lovely species. Fortunately much of our chalk downland is now open access, so the tedious business of seeking permission is avoided. I am wondering whether we can run a census of both species this year. As with the musk orchid, this will take you to some prime sites. A full species list from the site would be appreciated even if the target species is not found, but please send in the negative records.

Kew’s Millenium Seed Bank would like Thesium seeds from Dorset (Ted Pratt is coordinating this. Please contact him if you would like to help: email e.pratt@uwclub.net - telephone 01929 427229. So there is another reason for looking for sites, but please do not collect seed until you have full instructions from the MSB and we are sure the site can stand it.

General recording
Dorset’s flora is relatively well known in terms of distribution at the tetrad level. Not that that means we know everything – there is still plenty of fun to be had. I would like to move forward from simple species records into a better understanding of the ecology and habitats. To this end I would encourage collection of species lists for well defined sites, in preference to a grid square. And if a single species is the interest, the use of the rare plant recording form. If you do not want to use the form, at least keep it as a check list and record the information listed.

DFG contacts

For further information please contact:

Contact:	Carolyn Steele or Jon Crewe
E-mail:	derc@dorsetcc.gov.uk or crewie3@btinternet.com
*Telephone:*	01305 225081