Autumn Lady's-tresses

It seems to be a good year for Autumn Lady's-tresses Spiranthes spiralis. A small population (maximum count of 36 spikes so far) has appeared apparently out of the blue at Swaddywell Pit in VC32, growing in rather open structured grassland with Lesser Centaury Centaurium pulchellum, and close to a number of Common Spotted-orchid Dactylorhiza fuchsii and Southern Marsh-orchid Dactylorhiza praetermissa.

Today I received an email from Jeremy Fraser of the Lincolnshire Wildlife Trust, who visited the well-known population at Tydd Gote Pumping Station, on the Lincolnshire - Cambridgeshire Border on 24th August. He counted 274 plants in three main areas, which is the highest count in recent years, though somewhat short of the estimated 1000-2000 recorded in 1983. A worker from the pumping station confirmed that the plants had flowered particularly well this year.

The other main population in VC53 was on the drain bank at Surfleet Seas End (TF285302), but there are no records from here since 1997. Perhaps this would be a good year to go and have another look!

Cranwell and Bloxholm

On Sunday I set off in the cool of the morning for a day's botanising in some under-worked parts of the vice-county north-west of Sleaford. My first stop was the village of Cranwell (having driven swiftly through the RAF college whose grounds seemed far too orderly to hold any botanical jewels). This is one of the more intensively arable parts of VC53, but has limestone soils, and there were still fragments of species-rich grassland with an abundance of Field Scabious Knautia arvensis along the green lane and footpaths that I walked.

However, the arable field margins at the top of the hill were the richest hunting ground, with smoky clouds of Common Fumitory Fumaria officinalis, sprawling masses of Round-leaved Fluellen Kickxia spuria, Musk thistle Carduus nutans in profusion and five plants of Prickly Poppy Papaver argemone, a species that was once widespread in south-east England, but is now considered to be Endangered in the England Red List. It's only the second time I've found it, the first being almost thirty years ago. The small orange-red flowers are very distinctive, and only last a day. In fact in hot weather, the petals seem to drop by lunchtime, so one to get up early for!

Papaver argemone

Seed-head of Papaver argemone

The soft, hairy leaves of Kickxia spuria

Flower of Kickxia spuria

One of many plants of Kickxia spuria

Carduus nutans as an arable weed

By half past ten it was getting pretty hot, but I drove round to the northern part of my first tetrad, where a number of fields had been some with a wildflower mix containing plenty of Chicory Cichorium intybus and the fodder form of Bird's-foot-trefoil Lotus corniculatus var. sativus. 

On the side of a green lane I spotted three rose bushes that were quite upright in form and just looked a bit different from the Dog-rose Rosa canina I had been seeing scrambling through the hedges. I managed to extract some samples (reminder - carry secateurs!) and when I keyed them out they seemed to fit well with Round-leaved Dog-rose Rosa obtusifolia, which has strongly reflexed bipinnate sepals that fall early, and neat, rather overlapping biserrate leaves that are pubescent. There are few records for this species in VC53 and this seems to be the first since 1989.

Views of Rosa obtusifolia hips and leaves

By the time I returned to the car at about midday, it was really very hot and steamy, but I felt I couldn't give up and went for a walk around a contrasting area of sheep-grazed grassland and woodland west of Bloxhom. Initially it didn't seem as interesting, but on a very ordinary wayside I found a couple of plants of Good-King-Henry Chenopodium bonus-henricus, another rare species that's now considered to be Vulnerable in the UK, and one I'd never seen before. It is an archaeophyte, present in Roman times and once grown for its edible leaves - one of its vernacular names is Lincolnshire Spinach! It often grows in scruffy areas and has declined enormously, possibly as a result of the general tidying of ruderal vegetation.

Plants of Chenopodium bonus-henricus in improved grassland 

Weird willow

As it was a glorious morning, Pete and I went for a walk to Ring Haw quarry, always a good spot to see the first hairy violets of the year. Sheltered corners were positively cosy in the sunshine, bringing out the first spring butterflies - a brimstone and two peacocks - as well as a basking lizard. We also heard the first chiffchaff of the year, bang on cue.

As expected the Goat Willows Salix caprea were flowering, plenty of males (top right) with their iconic golden bottlebrush catkins, and some of the more subdued females (bottom right). But we also came across one large tree that was very peculiar (left). The catkins were large, shaggy and a vivid bright green in the early morning sun - they were also popular with bees. On closer examination it became clear that this particular tree was hermaphrodite, with both anthers and stigmas developing in the same flower head. This phenomenon appears to have been known for several hundred years, but is remarkably unusual - willows are normally strictly dioecious - and this is the first hermaphrodite willow I've ever noticed.

Heckington - a fen-edge village

On Saturday 19th March a group of six botanists form the South Lincolnshire Flora Group braved the north-east wind to record plants in Heckington. We started in the car-park of the famous eight-sailed windmill, and found an interesting area of waste-ground behind it which kept us occupied for quite some time. There was an interesting mix of ruderals and garden throw-outs, including a single very healthy-looking plant of Spanish-dagger Yucca gloriosa. It was too early to record some potentially interesting species, such as a Lamb's-lettuce Valerianella sp. and an Evening-primrose Oenothera sp., but the rather fine grass, which initially looked like a rather weak Red Fescue, was identifiable and proved to be Rat's-tail Fescue Vulpia myuros, which was last recorded from the same location in 1975 by Miss. E. Gibbons.

A puzzling ragwort Senecio will need a return visit to be sure of its identity - the leaf shape was reminiscent of Oxford Ragwort Senecio squalidus, but it was too hairy. On further examination it seems to have characteristics of both S. squalidus and Groundsel S.vulgaris, so could possibly be their hybrid, S x baxteri. However, to be sure of this, it will be necessary to see whether the flowers have ray-florets, and whether any viable achenes are produced!

We recorded many of the usual suite of urban species while walking through the streets of the village, but a couple of plants of flowering Rocket Eruca vesicaria subsp. sativa were a bit of a surprise. The appeared to be self-seeded in an area formerly planted as a herb garden, but now neglected. Other highlights of the street flora included rather frequent patches of naturalised Glory-of-the-snow Scilla forbesii, two populations of Spotted Medick Medicago arabica (one of which was in exactly the same spot where Malcolm Pool recorded it in 2001) and a good population of Hart's-tongue Fern Asplenium scolopendrium on the north-facing wall of Heckington Hall.

Flowering Rocket

Although the cemetery looked rather well-groomed, the grassland had areas of interest. There was a significant population of Common Wood-rush Luzula campestris, just coming into flower, as well as a scatter of species such as Ox-eye Daisy Leucanthemum vulgare, Sweet Violet Viola odorata, Primrose Primula vulgaris, Cowslip Primula veris and Sorrel Rumex acetosa. A semi-naturalised population of Green Snowdrop Galanthus woronowii prompted some discussion on snowdrop identification. Unfortunately the churchyard was significantly less interesting botanically, but we made up for that by exploring the interior, which has one of the finest stained-glass windows in Britain.

All-in-all it was a satisfying day, both botanically and culturally. We recorded in two tetrads, and found 155 species (90 new) in TF14L and 110 (38 new) in TF14M. I can also recommend the tea room at Heckington Windmill where we had both lunch and afternoon tea - very necessary in the rather cool and grey conditions.

A brownfield jewel

Sandwiched between the River Nene and the Peterborough to Cambridge railway line there is a little sliver of brownfield land, the remains of the old Peterborough East station, which is probably the most botanically important area in the city centre. If you travel on the Cambridge train you can pick it out by the startling chrome-yellow sheets of Biting Stonecrop Sedum acre that are in flower at the moment. 

The best quality habitat is to the west of the Frank Perkins parkway, and is easily accessible from a well-used footpath to Stanground. The area forms part of a more extensive corridor of brownfield land along the railway, which further east is included within the Wildlife Trust's Stanground Wash nature reserve. The substrate is formed from railway clinker, which is very nutrient poor and highly base-rich when fresh, but over time the calcium ions leach out leaving areas of more acid substrate. These unusual properties encourage a very rich flora, with both calcicole and calcifuge species growing in close proximity.

Peterborough East station shares many characteristic species with the railway land at Stanground Wash, including Viper's Bugloss Echium vulgare, Common Stork's-bill Erodium cicutarium and Perforate St.John's-wort Hypericum perforatum but it also has strong populations of several species that are not known from the nature reserve, such as Heath Speedwell Veronica officinalis, which is considered to be Near Threatened in England, and Grey Sedge Carex divulsa subsp. divulsa.

Viper's Bugloss, a typical brownfield species

Heath Speedwell, a calcifuge species which is well-established adjacent to the railway fence

The most important of these additional species is undoubtedly Wall Bedstraw Galium parisiense, a species that is listed as Vulnerable in Red Lists for both the UK and England. This diminutive cousin of Cleavers Galium aparine is a small annual of bare ground, favouring very nutrient-poor, summer-parched substrates which prevent competition from more robust species. This predominantly Mediterranean species is largely restricted to the warm and dry climates of the south-east but many former populations have been lost. There are only a handful of populations in Cambridgeshire, the most important of which occur on similar substrates at Whitemoor Railway sidings in March and at Conington tip, where it was introduced with translocated soils from Whitemoor. The population at Peterborough East station is well-established and numbers many hundred individuals.

The sprawling mats of Wall Bedstraw on typical railway substrate

Wall Bedstraw only reproduces by seed

Like many brownfield sites, the flora of Peterborough East station  also contains a number of species that have become established in the UK more recently such as Large-flowered Evening-primrose Oenothera glazioviana. However, the presence of sheets of a small, fluffy grass with noticeably purplish awns was initially a puzzle, but after a little detective work it was confirmed as Southern Beard-grass Polypogon maritimus. This species is slenderer than Annual Beard-grass Polypogon monspeliensis, which is now widely established in brownfield sites around Peterborough, and has more deeply bifid and longer hairy glumes and an unawned lemma.

Sheets of Southern Beard-grass, with noticeably purplish awns

A single spike of Southern Beard-grass

Detailed structure of Southern Beard-grass florets

Southern Beard-grass has rarely been recorded in the UK, but several of the previous records are associated with railway land. It has been recorded in Cambridgeshire once previously, at Cottenham, but has never been recorded from the Peterborough area. The population at the Peterborough Station East site is considerable, numbering many thousands of individuals.

The invertebrates of the site have scarcely been looked at, but even based on a half-hour of superficial examination, are interesting. Biting Stonecrop Sedum acre supports the rather local bug Chlamydatus evanescens, at one of its most northerly British locations; Stork's-bill Erodium cicutarium has the very local squashbug Arenocoris falleni and the only currently known Peterborough population of the burrower bug Odontoscelis lineola at the northern limit of its British range; and two Nationally Scarce weevils, Sibinia primita and Gronops lunatus, are associated with Pearlwort Sagina spp.

The whole site is included within the Fletton Quays Opportunity Area and will be developed in the near future. Listed buildings on the site will be protected and enhanced, and it is to be hoped that the same enlightened attitude will be taken to this biodiversity hot-spot, which could provide a colourful and low maintenance area of open space for all the residents of the city to enjoy.

Orchid Hunting

Chris and I took a couple of hours off this morning to go orchid hunting at a couple of local sites. Our first stop was Southorpe Meadow NR, where a Greater Butterfly Orchid had been reported. We found it quite easily, a bit worse for wear, but now protected by a wire cage. The hay-meadow was looking in very good condition, and there were many other orchids present, including Southern Marsh Orchids, Common Spotted Orchids, Pyramidal Orchids and Bee Orchids. 

Greater Butterfly Orchid Platanthera chlorantha

Southern Marsh-orchid Dactylorhiza praetermissa

 

Common Spotted-orchid Dactylorhiza fuchsii

Pyramidal Orchid Anacamptis pyramidalis

Bee orchid Ophrys apifera

Dactylorhiza orchids are very promiscuous and we also found the hybrid between Common Spotted and Southern Marsh Orchid Dactylorhiza x grandis and a rather more mysterious form which I suspect is a hybrid between Southern Marsh and Early Marsh Orchid Dactylorhiza x wintoni, as well as a splendidly deep purple specimen that is probably another hybrid.

Mystery orchid - very deep purple, quite large, with unspotted leaves and well-marked loops on lip

Dactylorhiza x grandis

Dactylorhiza x wintoni?

Very narrow flowers of possible D. x wintoni

We then headed out to Barnack Hills and Holes where there were sweeps of Fragrant Orchids. Chris had wanted to see Man Orchid and I managed to find one that was still flowering, though most were long over. However, the highlight was finding three Frog Orchids, two of which were extremely tiny. The other botanists examining them rather gave away their location! So within 10 miles of home we'd managed to see 10 different orchid taxa within the space of two hours - not bad at all!

A slope covered with Fragrant Orchids Gymnadenia conopsea

Fragrant Orchid Gymnadenia conopsea

A very tiny Frog Orchid Coeloglossum viride

The largest Frog Orchid, about 12cm in height

Galanthophilia

Snowdrops are still in flower and it's a good time to record them from your local area. The most frequent species naturalised locally is Snowdrop Galanthus nivalis, which can be recognised by its entirely glaucous (blue-green) leaves which are flat and less than 1cm in width. The inner tepals have a green patch at the apex only. This is the species that is so abundant in Old Sulehay Forest and at Orton Woods.

G.nivalis in Old Sulehay Forest

Quite often the double form 'flore pleno' can be found. This is present in Thorpe Wood NR and in many churchyards.

G.nivalis 'Flore Pleno' in Thorpe Wood

There are three other species that may be found occasionally in our area, most frequently in churchyards and cemeteries where they may originally have been planted. All three can be found in St. Botolph's Churchyard at Longthorpe.

The most distinctive perhaps is Woronow's Snowdrop Galanthus woronowii, as it is the only snowdrop that has a clear green leaf with no trace of glaucous colouration. Like G. nivalis, this species only has a green patch at the tip of the inner tepal. This appears to be fully naturalised in Longthorpe Churchyard, and I have also seen much smaller groups in several Lincolnshire churchyards this spring.

G.woronowii well established in Longthorpe Churchyard

Flowers of G.woronowii

Greater Snowdrop Galanthus elwesii has very glaucous leaves, but at least one will be more than 1.5cm wide after flowering, the leaves have their margins rolled when they are young and have a hooded apex. This species can have green patches at either just the apex, or at the base and apex of the inner tepals. I've never seen this species in large numbers, but it is occasionally present at low frequency in populations of G.nivalis.

G.elwesii in Longthorpe Churchyard

G.elwesii

The last species is perhaps the rarest, and in some ways can be the trickiest to identify. Pleated Snowdrop Galanthus plicatus has glaucous leaves, but the margins are folded under at least along most of the length, especially when young. Although this sounds a relatively easy character it can be quite tricky to notice. The leaves are also supposed to have a paler central band on the upper side. Like G. elwesii, the inner tepals can be marked with green either just at the tip (subsp. plicatus) or at the apex and base (subsp. byzantinus).

G.plicatus in Longthorpe Churchyard

G.plicatus subsp. plicatus

Do have a closer look at your local snowdrops in the next couple of weeks and see if you can spot some of the less frequent species. Of course, like many plants, they will hybridise, but that's another story...