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.