Thursday, 12 July 2018

Keys to grasses in Oxfordshire



Above: Ruth's multi-access key to the grasses of Oxfordshire developed using the Field Studies Council's Tomorrow's Biodiversity software. Below: Ruth's guide to grasses on iNaturalist.

Local botanist Camilla Lambrick has asked me to advertise some really great resources put together by herself and Ruth Ripley to aid with the identification of grasses in the county. Camilla says:

"Have you ever been frustrated that the grass you keyed out only grows in Shetland, or you have forgotten which a lemma is? Now, like buses, not one but three new keys to the grasses of Oxfordshire are available, developed by Ruth Ripley and illustrated with clear pictures:
  • The simplest to use of the three keys is the one on iNaturalist, available as a tablet or mobile app.  In this key you can choose easy features and instantly see photos of all the possible species. If you click on a photo you will find more information and photos.
  • A second online but more complex multi-access type key uses the Field Studies Council Tomorrow's Biodiversity software, available as a test version. This key gives a wide choice of features to compare together. This key illustrates the possibilities of the software — if you find it useful and would like it developed further please tell us!
  • A conventional dichotomous key by Camilla Lambrick can be found here. This key uses more technical terms, but it has a glossary.
None of the three keys are fully complete with recent introductions and cereal crops, but we hope to add to them. We would welcome your feedback and photos. Please email Ruth or Camilla.

Good hunting!"

Monday, 21 May 2018

Spring Atlas recording

May is always a very exciting time of year, and in the few weeks since I last posted there have been two Atlas recording meetings which I have organised, several ad hoc outings of my own, and I have had records from other botanists out recording themselves. I therefore thought I'd share some of the interesting findings from this early part of the season. If you've sent me records or participated in recording events and would like to see how your contribution has added to Atlas progress in the county, then I have updated the interactive Atlas map. I find this a useful tool for targeting my own recording and tracking progress and will update it every week or so.

The target areas for the last couple of my meetings have been rather underwhelming, Tusmore Park (SP53) this last Sunday being very sterile, and Fringford (SP62) two weeks ago also uninteresting. However, without much to keep one in a square there is the opportunity to range more widely and collect a greater number of records from a larger area. Beyond Tusmore on Sunday, we found many nice grassland plants along the A43, with Anthyllis vulneraria (kidney vetch), Briza media (quaking grass), Hippocrepis comosa (horseshoe vetch) and Lithospermum officinale (common gromwell) all new to the Oxon part of SP53. Also new to the Oxon part of the hectad was Carex distans (distant sedge), an uncommon plant of floodplain meadows and fens, found here by a carp pond by the brook that forms the boundary with Northants. It is also a plant of saltmarshes, and within the pond was a very surprising saltmarsh species, Bolboschoenus maritimus (sea club-rush), a county first. It may have been planted, but it is a very unusual choice of planting! It has been known from brackish marshes inland in other parts of England, such as at Marcham in VC 22, but never in VC 23. Salt-loving plants in Oxon are confined to the edges of salted roads, and indeed along the A43 we found the under-recorded halophytes Cochlearia danica (Danish scurvy-grass), Pucinellia distans (reflexed saltmarsh grass) and Spergularia marina (lesser sea spurrey).

Monday, 23 April 2018

Cottisford


The 2018 recording season is truly upon us, and Sunday was the first of several Atlas 2020 recording meetings I will be organising this year. The target was far-flung Cottisford, an area in the north of the county I had never been to before, and I was joined by four other keen botanists for a delightful day botanising in glorious spring weather. I had identified this square (SP53V) as a target for recording using the interactive Atlas 2020 coverage map available here. Although the tetrad had around 150 taxa recorded it still had a low recording rate indicating there was much else to find, so the aim of the meeting was to focus on species and habitats not covered by previous records: as these were focused on the Cottisford Pond Local Wildlife Site (LWS), there was plenty other ground to cover. Notable plants to look out for included Astragalus glychyphyllos (wild liquorice), last seen in 1993, and Carex elata (tufted sedge), last in 1968. Read on to learn whether we found either!

We started off in the churchyard in the village, St Mary the Virgin, where we had the usual lawnmower-tolerant species of unimproved churchyard grassland such as Plantago media (hoary plantain). There was a single rosette of Dactylorhiza fuchsii (common spotted orchid) and an abundance of flowering Luzula campestris (field wood-rush), an understated spring beauty. Making out of the village for the area where the Astragalus was last recorded we came upon a few patches of flowering Rancunulus auricomus (goldilocks buttercup) in a hedgebank. Further along were scraps of limestone grassland with an abundance of Cirsium eriophorum (wooly thistle) and a few plants of Lithospermum officinale (common gromwell), which was new the to square. Also new was Hypericum maculatum (imperforate St John's wort), relatively scarce in Oxon, and further up the lane we found the sought-after Astragalus, much to our delight. There were a mere five small tufts of this species growing in a rather unprepossessing verge by a farm track.

The next few hours were spent wondering along footpaths picking up records from a variety of habitats. Two large fields of Linum usitatissimum (cultivated flax) provided many arable weeds, welcome as these are usually scarce so early in the year. The company disbanded after hunting out the plants of Cottisford village, where we found rather few garden escapees, and I headed out alone to the last recorded location of Carex elata. I was quickly disappointed as this was an arable field, but diving into the woodland in the shallow valley below I immediately found around 20 tufts in a spring-fed swamp - as Carex elata had been known from only one site in the county this was clearly a significant find! I continued to find further plants, keeping count until I came across a large area of flooded woodland that supported thousands of individuals, and I was puzzled as to how this plant had been missed here for fifty years! Several large tussocks were also growing in Cottisford Pond itself.

Right: a tussock of Carex elata growing in Cottisford Pond. Below left: its wet woodland habitat. Below right: a diagnostic feature of C. elata is the leaf-sheaths, which split into many ladder-like fibres.

The woodland around Cottisford Pond had plenty of other good plants to add to the list, with a range of ancient woodland and wetland species. Neottia ovata (twayblade) and Valeriana dioica (marsh valerian) were both new to the tetrad, the latter a surprise as I had never known this uncommon and threatened species to ever turn up at a new site or to grow in woodland. To the south above the valley, the woods on the hill and the small area of Shelswell Park within the tetrad added a good deal of further interest. This area supported acid grassland, a very rare habitat in Oxfordshire, and I was able to re-record Campanula rotundifolia (harebell), Cirsium acaule (dwarf thistle) and Galium saxatile (heath bedstraw) as well as add Carex caryophyllea (spring sedge), Filipendula vulgaris (dropwort) and Veronica officinalis (heath speedwell) new to the tetrad. The glacial sand and gravel deposits across this part of the county, from Hardwick north-east to Finmere and Mixbury, would certainly be worth further survey.

After a bit more back-and-forth along footpaths to try to pick up extra species, I eventually returned to Cottisford carrying a satisfyingly full recording card. Together the meeting bumped the tetrad up to a total of 300 taxa, recording 260 taxa and making 287 records, greatly exceeding my expectations. It was particularly gratifying to find so many new native species and few aliens for a change, and of course to re-record a number of locally important plants. Who knows what we will find in a forthnight's time at the next meeting on May 6th? Please email me if you'd like to join us.

Sunday, 15 April 2018

Atlas recording 2018

This is a short post to advertise opportunities to get together with local botanists this season and help with the penultimate season of recording for Atlas 2020. I will be organising recording meetings every other weekend through the season under the aegis of the Oxfordshire Flora Group, with the first meeting on Sunday 22nd April in the north of the county in Cottisford. I am also going to be running an 'official' BSBI meeting on 16th June, but so far my organisation hasn't progressed beyond fixing a date and the vague locality of the Chiltern Commons. Get in touch with me if you would be interested in coming along to any of these. The Wychwood Flora Group will also be running recording meetings in the west of the county, mostly on weekdays. Email the group if you are interested in joining any of their outings.

The above recording meetings and more are all listed in the events calendar which you can view here.

As a teaser for the kinds of plants you might see while out on a recording meeting, this is a photograph of the nationally scarce Helleborus viridis (green hellebore) that Oli Pescott and I found growing in great plenty along part of Grimm's Ditch near Nuffield in the Chilterns while we were out recording today. It was a very special sight and we found many other nice woodland plants, including Viola reichenbachiana x riviniana (=V. x bavarica), only the third county record. Is it overlooked in Oxon? Keep an eye out for intermediate-looking violets this spring!

Tuesday, 13 March 2018

Atlas 2020 update

This post is just a short announcement and advertisement of the updates I have finalised to the Atlas 2020 page describing the project and progress with recording for the Atlas in Oxfordshire. I have over-hauled the previous interactive tetrad map, as you can see below. It includes a function to display areas in need of attention as well as the more usual illustration of well-recorded areas, and provides links to full lists of taxa recorded in each tetrad. I hope this will be of use to botanists planning recording this season.

Thursday, 8 February 2018

The year in botany


Recording plants at Somerton during a field meeting in May 2017
Now that we're well into the new year I thought it about time I had a look back at 2017. Much more happened during 2017 than can be summarised here — you can get an idea of local activities during the last year by reading the blog posts. If you've any highlights you'd like to share then consider leaving a comment below this post. It was a memorable year for me, not least as it was my first full year in the post of vice county recorder. I have enjoyed beginning to get to know the county's flora and its botanists, particularly through meetings (ten of which were covered on the blog). Numerous local botanists have also been out enjoying themselves outside of meetings, and it has been a pleasure receiving their records and learning what they've been up to. It has been particularly gratifying to see new recorders find their feet (there was a beginner recorders' meeting in April), and for me to be in a position to assemble everyone's contribution to Atlas 2020.

So far 13,623 records made during 2017 have been submitted to the BSBI Distribution Database (DDb). A further 4,114 records were submitted to iRecord, but these have yet to migrate over to DDb. iRecord submissions were almost double that of last year due to new recorders taking up this platform, but 13,623 is a bit of a dip for the DDb compared with 2015 and 2016 when over 24,000 and 25,000 were submitted, respectively. If you have records please therefore send them to me! I blogged earlier in the year about the the vascular plant record sharing agreement with Thames Valley Environmental Record Centre (TVERC), which was quite a big development, making a huge difference to the BSBI's Oxon data holding, with over 340,000 records received. Many recorders over the last couple of decades have preferred to send their records to TVERC, and being able to tap this activity has made a significant contribution toward Atlas 2020. It has been and continues to be a big job to check all these records but it is worth the effort!

I'm sure you're desperate to read how the county is getting on with Atlas 2020 following the 2017 recording season — the up-to-date tetrad (2km square) progress is shown in the map to the left, based on DDb records from the beginning of 2000 to present. This shows more clearly than maps I've previously published how survey effort has been expended, with both tetrad total taxa (tetrad colour) and total recording rate (tetrad size) illustrated. While coverage of the county has continued to improve, one can see that there is work to do in terms of consolidating the recording done to date, i.e. increasing the cover of 'bigger squares' (generally a recording rate of 60% requires about 200 taxa to have been recorded), and recording in the far-flung areas around the county boundary. This is essentially the message I've communicated previously, such as on the Atlas 2020 page, so we just need to keep on working at this up to the conclusion of the Atlas recording period.

The Oxford and Otmoor areas (SP50 and SP51) exemplify the situation we would ideally like to reach but as I've said before it is not essential or possible to fill every gap. At the scale of hectads (10km square), which will be the mapped units in the published Atlas 2020, most now stand at 50-60% recording rate or better (and similarly for the re-find rate), and most have at least 20% of tetrads with 100 or more taxa recorded, which is quite a good situation; targeted recording during 2018 and 2019, including repeat visits to tetrads, will improve the recording rate. Please do get in touch if you need help identifying areas for recording in your area.

Tetrad coverage for Atlas 2020, with tetrads coloured by number of taxa recorded since 2000, and square size scaled by total recording rate, i.e. the proportion of taxa recorded since 2000 out of all taxa recorded.


Above: Potamogeton nodosus in the Thames, Frank Hunt. Right: Carex muricata subsp. muricata in the Chilterns, Geoff Toone.
Now I come onto the less dry developments of 2017, the records of notable plants. The record that stands out of course is Frank Hunt's rediscovery of Potamogeton nodosus (Loddon pondweed) in the Oxfordshire part of the River Thames, a nationally rare species which had only ever been known in the county for a short period during the 1940s. Its reappearance in the Thames it turned out had actually already been established on the Berks and Bucks reaches of the river by the Environment Agency a few years ago, but this was still a very exciting record for Oxon. This rediscovery follows that of Rosa agrestis (small-leaved sweet-briar) in the county in 2016 — I hope that we may have a rediscovery every year!

Recording meetings during the year turned up many records of note. Less satisfactory was the grotty umbellifer found growing submerged in the River Cherwell during the meeting in Somerton in May: it was suspected to be Oenanthe fluviatile (river water-dropwort), thought extinct in the county, but later searching could not relocate it and its identity remains a mystery. On the same meeting was re-found a small population of the uncommon crowd-pleaser Saxifraga granulata (meadow saxifrage), a larger population of which was also rediscovered in December at Peppard chuchyard on the New Year Plant Hunt. With the county generally quite under-recorded, there are plenty of opportunities such as these for re-finding notable plants at old localities as part of Atlas recording, e.g. Fay Banks' Sambucus ebulus (daneberry) at Garsington this last year. Recording also turns up unusual or casual plants, and this year I had an odd weekend when several records of the locally rare Anthriscus caucalis (bur chervil) were sent to me.

Finally, a little-known Oxfordshire plant, the nationally rare Carex muricata subsp. muricata (large-fruited prickly sedge), came to my attention this year when I received a batch of records from Geoff Toone and Paul Stanley from back in 2011. Only discovered in the county early in the 2000s (I think at Hartslock, though I can't find the record), this sedge is beginning to emerge as potentially quite a widespread plant of Chiltern beechwoods, and many thanks are due to Paul, Geoff and others for continuing to track it down.

Sunday, 4 February 2018

Beacon Hill bryophytes

Beacon Hill, part of the Aston Rowant National Nature Reserve, was the latest destination for the bryophilic element of the Oxfordshire Botany Group (28/01/2018). Three members assembled for a bryological recording session around the chalk grassland and woods of the hill (SU7296 & SU7297), a location that has not been thoroughly surveyed for bryophytes since Ron Porley's study of Chiltern chalk grasslands in the mid-1990s. We admittedly had a fairly easy-going recording session, and so I don't think we would claim that we surveyed the site anywhere near as intensively as Ron, but we recorded 53 species (67 records) across two monads, and refound a few of the characteristic species noted by Porley, as well as some species which appear to be new for the Hill.

Looking across to Aston Rowant from Beacon Hill.
Fissidens dubius
Focusing first on the west-facing slope around SU728968, we quickly picked up a slew of typical chalk grassland species, including Homalothecium lutescens, Fissidens dubius, Plagiomnium affine, and Weissia longifolia. Here we also found our first plants of Rhodobryum roseum, a particularly large and handsome moss that tends to be indicative of habitats that are of importance for nature conservation (due to its requirement for an open, low nutrient sward), and was unfortunately one of the species included in the "decreasing generally" category of Mark Hill & Chris Preston in their analysis of change in the recent Atlas of British and Irish Bryophytes.

Rhodobryum roseum
Rhodobryum in a typical anthill setting
Later on, in a "hollow way" lane cutting down the west-facing escarpment we recorded a good number of epiphytes, most new for the site, including two attractive Neckera species, N. complanata (pictured) and N. crispa. Here we also found a number of more weedy species existing on the risers and treads of wooden stairs installed for easier access, including Orthotrichum anomalum, Campylopus introflexus, Barbula sardoa, B. unguiculata, and Homalothecium sericium.

Neckera complanata
After lunch, we were back on higher-quality ground, inspecting the open expanses of grassland on the plateau of the hill, around SU727971. Here, after some patient hound dog style searching, we were rewarded with a cluster of rarer chalk grassland pleurocarps. These included Campylium protensum, Entodon cocinnus, and Hypnum cupressiforme var. lacunosum. The first of these has apparently not been reported for Beacon Hill, and is rare in chalk grassland in Oxfordshire; E. cocinnus is known from Beacon Hill, but has not been reported recently, at least according to records available from the British Bryological Society and the NBN.

Campylium protensum
Entodon cocinnus
The full list of species for the day is given below. Another visit will certainly be in order, as there are a number of nationally scarce bryophytes found by Porley that we didn't manage to rediscover.

Liverworts Fissidens dubius Zygodon conoideus var. conoideus Plagiomnium undulatum Brachythecium rutabulum Entodon concinnus
Metzgeria furcata Fissidens adianthoides Orthotrichum affine Campylium protensum Brachythecium salebrosum Cryphaea heteromalla
Radula complanata Dicranum scoparium Orthotrichum anomalum Amblystegium serpens Homalothecium sericeum Neckera crispa
Frullania dilatata Campylopus introflexus Orthotrichum diaphanum Thuidium tamariscinum Homalothecium lutescens Neckera complanata
Lophocolea bidentata Weissia longifolia Bryum pallens Pseudoscleropodium purum Calliergonella cuspidata
Mosses Barbula convoluta var. sardoa Bryum capillare Eurhynchium striatum Hypnum cupressiforme var. cupressiforme
Seligeria calycina Barbula unguiculata Bryum pseudotriquetrum Rhynchostegium confertum Hypnum cupressiforme var. lacunosum
Fissidens viridulus Didymodon vinealis Bryum dichotomum Oxyrrhynchium hians Hypnum cupressiforme var. resupinatum
Fissidens incurvus Syntrichia ruralis var. ruralis Rhodobryum roseum Oxyrrhynchium schleicheri Ctenidium molluscum
Fissidens taxifolius Zygodon viridissimus var. viridissimus Plagiomnium affine Kindbergia praelonga Rhytidiadelphus squarrosus

Thursday, 11 January 2018

Hinksey Heights Bryophytes


Botanists enjoying a coffee break in the wood along the valley
Sunday was another winter outing for local botanists, this time on the Hinksey Heights south of Oxford and better attended than the last. Hinksey is in vice county 22 (Berkshire) meaning a day off recording vascular plants for me, but the meeting was focused on bryophytes anyway. The main interest was one of a series of long narrow valleys draining north off the heights, fed by calcareous groundwater emanating from the limestone along the valley sides. There is peat in the upper part of the valley, and it was once an open fen rich in plants such as grass-of-Parnassus but now mostly covered in willow and reed.

The valley is a nature reserve and can be reached from the Hinksey Heights Golf Club via a footpath and board walk leading north-west from the car park (the temptation to botanise which was resisted). The valley opens out at the entrance near its bottom where there are fabulous views of Oxford and its encircling hills to the north and east. The southern slope here supported the only area of Juncus subnodulosus (blunt-flowered rush) fen we came across, but it was rather overgrown.

The stream tumbling over its tufa weirs
This is where we set to bryologising, and as there were a few new-comers to the subject we could share the revelation that is the tiny world of bryophytes, with ample demonstration material provided by the several common species growing on the accumulated fen litter. The only fen moss we found, however, was a scrap of Bryum pseudotriquetrum. The stream within the woodland in the valley bottom had me fantasising of Eucladium and Gymnostomum species, with its spectacular tufa weirs (or barrage tufa) and drifts of petrified leaves and twigs. Tufa is formed where limey waters precipitate calcite (the principle calcium carbonate mineral) onto lower plants and debris, encasing them in stone, and has a specialist bryophyte flora adapted to this highly alkaline environment. The bryophyte flora, however, was rather dull, most surfaces being covered in the pleurocarp Cratnoneuron filicinum, or the thallose liverworts Conocephalum conicum and Pellia endiviifolia. This suite of species followed us up the valley, dominating the weirs, dripping banks of the stream and springs.

The peaty springs higher up were a little richer, but mostly covered in wefts of the common mosses Plagiomnium affine and P. undulatum. Exceptionally, however, and the highlight of the meeting, both species were producing sporophytes, which for P. affine is a very rare occurrence. Most species of Plagiomnium are dioecious (sexes on separate plants) and are shy to produce sporophytes — the only currently known record of P. affine in fruit in Oxfordshire or Berkshire is from nearby Bagley Wood, found by Watson many decades ago.

Fruiting Plagiomnium affine growing with Cratoneuron filicinum in a tufa spring
Like the two Plagiomnium species, most of the mosses and liverworts we recorded were general calcareous woodland plants rather than specialists of wet woodland or fens. We recorded a number of epiphytes such as the increasingly common Orthotrichum pulchellum and O. stramineum, as well as the uncommon and Brachythecium salebrosum growing on an elder. Altogether we recorded 9 liverwort and 38 moss species, but with a few specimens yet to be examined this is not the final tally. Thanks to everyone for an enjoyable meeting!


Brachythecium salbrosum growing on elder (left). The meeting was too early for the pretty capsules of Orthotrichum stramineum (right, April, Blenheim Park) but old dry capsules are distinctively red-brown and flask-shaped.

Wednesday, 3 January 2018

New Year Plant Hunt


Had you been in Peppard on Sunday you might have witnessed Oli Pescott and I striding about the parish, peering into hedges and self confidently looking over garden wall at weeds, for the hunt was on. The New Year Plant Hunt of course, the national scheme run annualy by the BSBI between 30th December and 2nd January, which challenges botanists to find as many wild plants in flower as possible in a continuous three hour period. With Oli for company I managed to do one better than my solo plant hunt which I blogged about last year, and further media coverage was provided with Oli tweeting about our hunt (left). I'd be delighted to hear by any means of other local Hunts, just be sure to submit your records here!

The choice of locality for our Hunt was not the shrewdest as the biggest yields of plants in flower are to be found in areas with a diversity of disturbed habitats, with an abundance of weeds and garden escapes, while Peppard is mostly semi-natural . I thought we'd make it a little bit more fun by seeing how many bryophytes we could find 'flowering' too (i.e. producing sporophytes), and we also kept full lists of both vascular plants and bryophytes! In all we had 20 species in flower, some maybe questionably so — do the cleistogamous flowers of Poa annua (annual meadowgrass) count, and can one ever actually tell whether the tiny-flowered and petal-less Aphanes arvensis (parsley piert) is in flower? In addition to the weeds and garden escapes we had the winter-flowering specialists, with Daphne laureola (spurge laurel) and a male plant of Mercurialis perennis (perennial mercury) on Peppard Common, and some early vernal species such as Ficaria verna (lesser celandine). The total was a few more than my 17 of last year, and better than the bryophytes of which we found only 16 with sporophytes, all commonly producing capsules at this time of year.

Not in flower but the star find of the day was unquestionably the unexpected colony of Saxifraga granulata (meadow saxifrage) in the churchyard of Rotherfield Peppard, seemingly mown with a razor blade. This species had not been seen in the tetrad since the 1960s and previous records (including that of Druce) were unlocalised, so a really good record of this uncommon plant. If you recall, flowering Saxifraga granulata was a highlight of one of the first meetings of the season, lending a nice symmetry to the year. There was further interest among the bryophytes when we found a tiny moss growing on a garden wall — after some head scratching it was suggested that our plants might be the first county record of Leptobarbula berica, but we await confirmation of this.

In total we recorded 173 vascular plant taxa, not a bad haul for December and valuable additional records for Atlas 2020, as well as 51 bryophyte taxa. Oli and I will continue botanising throughout the 'off season', and will next be meeting in Hinksey on the 7th. Please email me if you'd like to join us.

Above: flowering Daphne laureola (spurge laurel) (top) and a male plant of Mercurialis perennis (perennial mercury) (bottom), typical winter flowering plants, found during a New Year Plant Hunt. Right: the delightful sparsely hairy rosette leaves of Saxifraga granulata (meadow saxifrage) growing in All Saint's churchyard in Rotherfield Peppard.