Friday, 30 May 2014

King's Dyke NR

While Pete led the annual bug-hunt, I concentrated on recording the plants and although I only covered a small part of the reserve I found plenty of interest. The summer-parched soils of the reserve support a good range of tiny annuals, including very large populations of Filago vulgaris, Valerianella locusta and Myosotis discolor. Other more local species of similar conditions include Torilis nodosa and Ranunculus parviflorus, which I've not seen there previously.

Torilis nodosa

Valerianella locusta

Myosotis discolor

Ranunculus parviflorus

A couple of species of orchid were also flowering, Dactylorhiza incarnata and Ophrys apifera, both growing near the edge of the lake, the latter just beyond the pond dipping platform.

Dactylorhiza incarnata

Ophrys apifera

However, the most unusual species was found growing abundantly in the lawn behind the Hanson offices, which is actually remarkably species-rich. At first I just couldn't place the blue starry flowers, but eventually I remembered that it looked like a Pratia sp., which I grew many years ago. After consulting various reference books it turned out to be Matted Lobelia Pratia pedunculata, a native of New Zealand which may well be a new record for VC29.

Lawn lobelia Pratia angulata, naturalised in mown grassland

Southey Wood

I'm still not travelling too far, thanks to the sciatica, so today Rosie and I had a walk round Southey Wood. I used to visit this a lot, but haven't been recently, so I was interested to see what I could find. It's a very rich site, with both ancient woodland and unimproved grassland on calcareous and acid soils, and I recorded 176 species in about an hour and a half, just from the paths. Highlights of the visit were:

Lots of Galium odoratum, at several locations

Carex pallescens at a couple of different places on the rides. This is a very occasional species, usually found on damp rides in ancient woodlands locally.

Ornithogalum umbellatum, on a ride edge. I have recorded this before from a different part of the wood. It is considered to be non-native in Northamptonshire, although in both cases at Southey Wood it was growing among semi-natural vegetation with no other apparent introductions.

Sanicula europaea, a local species of dry calcareous woodland, with one extensive patch growing near the car-park.

Aquilegia vulgaris, in the car-park, most likely an introduction but self-seeding and apparently well established.

Other species of note include lots of Astragalus glycyphyllos and locally frequent Oxalis acetosella on the more acid soils. Definitely a site to revisit later in the season!

Thursday, 29 May 2014

Annual clovers at Ferry Meadows

The sandy lake edges at Ferry Meadows must be one of the best places locally for annual clovers. I've already written about Trifolium micranthum on the west bank of Overton Lake. Today this area also supported sheets of knotted clover Trifolium striatum, as well as one or two white-flowered clovers that appeared similar to rough clover T.scabrum, but that I suspect are actually an albino form of T.striatum.

Trifolium striatum

Albino Trifolium striatum?
Even more exciting is a large population of bird's-foot clover Trifolium ornithopodiodes growing in very short goose-trampled turf on damp sandy soil along the south bank of Lynch Lake. This has been growing in the area for over twenty years, but somehow never seems to have been included in the Huntingdonshire records, despite me informing the previous BSBI recorder. It's very difficult to photograph, as the flowers are quite tiny, and normally occur in 1-4 flowered racemes. This winter annual is most freqiuent round the coast, but may get overlooked as it can be almost impossible to see!

Trifolium ornithopodioides

Wednesday, 21 May 2014

Castor Hanglands

It was such a lovely day that I had to get out, so I visited Castor Hanglands in preparation for a grass identification day that I'm leading on 24th June. It's an ideal location, as there's arable, neutral grassland, calcareous grassland, wetland and woodland all in a compact area, and I'm confident we'll be able to find a good range of species to identify.

As I walked round I also recorded the wider flora. It's an excellent time for recording sedges. most of which are flowering now. The marsh had lots of Carex disticha, as well as C. panicea and C. distans. All of these are very local, being largely confined to unimproved grassland. Around Peterborough C. disticha also occurs in alluvial meadows, but the latter two species are largely confined to damp calcareous grassland, often with springs or seepages.

Carex panicea

Carex disticha

Carex distans
 The marsh orchids were also coming into bloom. There were some Dactylorhiza incarnata subsp. incarnata, but most appeared to be hybrids. I find these very difficult to identify, particularly where there are more than two possible parents. At least some looked as though they might be D. x kerneriorum (D. fuchsii x D.incarnata), as they had rather pink flower with folded back lips and heavily spotted leaves, but they could be another taxon! Sedges are so much easier!!

Unsure about this one!

Possible Dactylorhiza x kerneriorum

Tuesday, 20 May 2014

Well away from home...

After a severe bout of sciatica on Sunday, I decided to stay close to home and went for a short walk through Thorpe Meadows and along the bank of the River Nene. I wasn't really botanising, but this rather showy geranium caught my eye.

There's a great deal of Meadow Crane's-bill Geranium pratense along that stretch of the river, but this was clearly different and reminded me of Wood Crane's-bill G.sylvaticum, which is very much a northern species that I've seen in Scotland and Northumberland. This provisional identification was confirmed when I got home and consulted Stace. It's apparently the first record for V.C.32, and is well out of its native range, so presumably has arrived through human intervention, though it's in a semi-natural area well away from any dwellings.  

Saturday, 17 May 2014

Hay meadow treasures

This morning I took a group from Rutland Natural History Society on a walk round a couple of hotspots in the Nene Valley. We started at Castor Station, where we looked at the riverside vegetation, enjoyed seeing plenty of Banded Demoiselles (it's going to be a bumper year for this species), found a freshly emerged Scarce Chaser and spent some time looking at  various fish and invertebrates that Pete had collected from the river, including some baby Spined Loach.

The botanical highlights came in the second part of the morning, when we visited part of Castor Flood Meadows SSSI which is owned by the Nene Park Trust. This unimproved hay-field proved to be a real gem, with all the species that you might expect - Sanguisorba officinalis, Silene flos-cuculi, Filipendula vulgaris, Ophiuoglossum vulgatum, Silaum silaus, Carex disticha - the list could go on.

However, there were three star species. On the slightly drier ground at the western end there was a good population of Meadow Saxifrage Saxifraga granulata, at one of its very few Peterborough sites.  It is now more frequent in churchyards and cemeteries than in old meadows. In the dampest part of the field we found two areas of Tubular Water-dropwort Oenanthe fistulosa, a much declined species which is now classified as Vulnerable in the UK RedList.

Saxifraga granulata

I was also delighted to see that the population of Early Marsh-orchid Dactylorhiza incarnata was still present (having last surveyed it over 10 years ago) and seems to be having a good year. Pete counted at least 100 spikes before he gave up. A number of the spikes were the classic pale flesh-pink of D.incarnata subsp. incarnata, but a much larger proportion were a deep pink, and key out to D. incarnata subsp. pulchella, which is supposed to occur on more acid soils, although it can occasionally occur in neutral marshes and fens, and recently has been found as a coloniser of fly-ash tips in the Lee Valley, Hertfordshire. Stace considers that the majority of the subspecies of D.incarnata would be better considered as varieties - so who knows?

Dactylorhiza incarnata subsp. incarnata

Dactylorhiza incarnata subsp. pulchella

Slender trefoil at Ferry Meadows

Last week I had a stroll round part of Ferry Meadows Country Park. There has been a lot of wildflower seeding in places, and at the moment there is a truly magnificent display of Red Campion Silene dioica , in a number of different shades, as well as at least one plant of the hybrid with White Campion, Silene x hampeana.

Silene dioica

Silene x hampeana

However, what I was really interested in was the flora of the gravelly areas. Rabbit diggings to the west of the car-park were fringed with a halo of Common Stork'sbill Erodium cicutarium, while the sandy areas on the west bank of Overton Lake had sheets of both Lesser Trefoil Trifolium dubium and it's much less common relative Slender Trefoil Trifolium micranthum. This latter species is pretty rare locally, being far more restricted to free-draining sandy soils than T.dubium. It may well be overlooked, but when the two grow together it is clearly different, forming a lower, denser mat of smaller leaves and the flower-heads consistently having tiny flowers with fewer than ten flowers in a raceme, often only two or three. This is one to look out for at Tallington Pits I think!

Flowers of Trifolium micranthum
Dense mat of T. micranthum
Erodium cicutarium

Tuesday, 13 May 2014

Annual geraniums

Now is probably the best time of year to record small annual geraniums. We have quite a good range locally - these five are perhaps the trickiest to identify.

Geranium molle has small, bright pink or almost whitish flowers with ten anthers. The leaves are dissected less than half-way and it has both silky long and short hairs on the petiole and peduncle. It's common almost everywhere.

Geranium pusillum has rather duller, more mauvish-pink flowers, with only five anthers and the hairs on the stems are all short. The leaves are somewhat more dissected than G. molle, but not as deeply cut as G.dissectum. It particularly seems to like areas which are summer droughted and is locally frequent especially in brownfield sites. It is often under-recorded, being mistaken for G. molle.

G.dissectum usually has small, bright pink flowers (the photograph above is of an unusually pale form) and has deeply-dissected leaves. It usually has a mix of short and long eglandular hairs. It is surprisingly variable and can be difficult to identify vegetatively, but is frequent to abundant in a variety of disturbed and grassy places, and is often a weed of arable fields

Geranium columbinum is probably the rarest locally, and is superficially similar to G.dissectum, but it has even more dissected leaves and short stiff eglandular hairs. Most pedicels are more than 2.5cm long, giving it the English name of long-stalked crane's-bill. It occurs regularly at Bedford Purlieus and has also been recorded recently from Castor. It normally grows on limestone soils.

Geranium rotundifolium seems to be turning up all over the place at the moment. A large patch has recently appeared on a route that I've walked regularly for about fifteen years. The petals are rounded at the apex. it has glandular hairs and the leaves often have red spots in the sinuses and at the ends of the lobes. It normally grows in bare stony places that are parched in summer.

Wednesday, 7 May 2014

Large Bittercress

I was relieved to see that the colony of Cardamine amara (Large Bittercress) in Bluebell Wood is doing well this year, as I hadn't recorded it for the past few years. This is a rare species in both Northamptonshire (VC32) and South Lincolnshire (VC53), and in the latter vice-county it is most frequent in TF00, with a number of records for the Stamford area, although most are quite old. It was most recently recorded in 2012 from Uffington Park, and there are also older records from Greatford, Thurlby Fen and Stoke Rochford. When flowering, it's easy to identify - the blackish-purple anthers and white petals distinguish it from C.pratensis. It is much more restricted to streamsides, marshes and flushes - at Bluebell Wood it only grows in one small seepage area, among Iris pseudacorus.

Three honeysuckles

A bout of sciatica has rather limited my botanical ramblings, but over the past few days I've recorded three non-native honeysuckles not that far from home.

The first was spotted growing as an isolated bush in a grassy field close to a bridleway north of Castor village  - it had pink flowers and was not a species I'd seen before. It turned out to be Lonicera tatarica (Tartarian Honeysuckle), which is usually bird-sown. This seems to be the only record for VC32, and it was first recorded by David Broughton in 2007.

Lonicera tatarica

The other two species are both growing close to the pond at the western end of Bluebell Wood. I've known for many years that Lonicera involucrata (Californian Honeysuckle) is naturalised there, and today it was flowering close to the path. It's easy to identify, being a shrubby species with ovate bracts at the base of the flowers, which are orange and have glandular hairs.

Lonicera involucrata

Somehow I seem to have completely overlooked the other species until today. There is a large bush of Lonicera xylosteum (Fly Honeysuckle) growing close by, which has tiny linear-lanceolate bracts and pale yellow to cream zygomorphic flowers. The young leaves and stems are also hairy. This only seems to have two localities in VC32, and was first recorded from Bluebell Wood in 2009.

Lonicera xylosteum