Friday 26 March 2021

More early spring flowers round the village.

I saw on Twitter a picture by Brian Laney, Northamptonshire's vice county recorder, who has encyclopaedic knowledge of Britain's flora, of a yellow-flowered plant, Yellow Monkswort (Nonea lutea),  which he described as the first record for Oxfordshire.  I thought I had seen it in Hook Norton a few days ago; a plant I did not recognise then, other than place it in the borage family, and I had  assumed it was a garden throw out, not worthy of further attention.  Yesterday I went to take a closer look, and sure enough it was Yellow Monkswort, a neophyte (an alien) of American origin, described as widespread in Britain but quite rare. The second Oxfordshire record.   It was on a bank under a low garden wall, near to some weeds - Groundsel (Senecio vulgaris), Ivy-leaved Speedwell (Veronica hederifolia), Hairy Bittercress (Cardamine hirsuta), -  but for me, someone who does not get too excited about alien plants, more interestingly by far, there were also a few plants of Muscari neglectum, a rare native plant.   This is in a few old gardens round the village, but is widespread on the village green in Chadlington, a few miles south.    I suspect it was commonplace in Hook Norton in the past, though there is no mention in Druce's 'Flora of Oxfordshire'. 


                                              Yellow Monkswort (Nonea lutea)

                                                          Muscari neglectum

In some villages churchyards are very good places to botanise.   The grass is cut too frequently for Hook Norton to be one of them, but yesterday there was at least a big splash of the bright yellow Lesser Celandines (Ficaria verna) in one corner.   There was also another alien, but not as uncommon, Rough Comfrey (Symphytum asperum) on a path leading to the churchyard . It is one I need to check whether I have got it right - if the leaves have short stalks then it is, but if they clasp the stem then it is Russian Comfrey. (I have been back since to have another look and it probably is Hidcote Blue, (Symphytum x hidcotense), though I could not see one of the key determinants - stolons)


     Lesser Celandines (Ficaria verna)              Probably Rough Comfrey (Symphytum asperum)

Finally I came across some Early Dog Violets (Viola reichenbachiana) at a crossroads under a wall, the first I have seen this year.   Because of where I found it I probably ought to check that one too, just in case it is a hybrid.  (I really should lug around with me the botanist's bible, Stace's 'New Flora of the British Isles', weighing just over 1.2 Kg, to avoid these uncertainties!).

Wednesday 24 March 2021

Early spring around the village

Still in lockdown, I walked a few miles south of the village to a couple of meadows.  Although still quite early, I counted 20 flowering plants, with violets and primroses adding characteristic colour to otherwise bare hedgerows and grasslands.  


           Hairy violet (Viola hirta)                               Primroses (Primula vulgaris)


                  Sweet violet (Viola odorata)

The plant thug, Dog's mercury was also just beginning to flower. Why a thug?  Well it creates a dense carpet which smothers other plants.  

In one of the meadows I found the rosette of a bee orchid;  there are usually a few but this was in a new location in the meadow.

Surprisingly I did not see any deer - there are usually a few around - but I did find some old otter spraint on a branch overhanging the River Swere.

Tuesday 23 February 2021

William Fowler Memorial Wood - a lockdown walk

 A short lockdown walk yesterday to a small reserve on the outskirts of Chipping Norton, the William Fowler Memorial Wood. Quoting from the website Chipping Norton Green Gym, whose volunteers maintain it:

"In 1892 a 23.5 acre (9.5 hectare) field called the Picked Close or Long Ground was given to the town of Chipping Norton by former resident Mr William Fowler, then living in South Australia. The field was to be let as working men’s allotments of ¼ acre each. A century on, the allotment land, which adjoins Glyme Lane close to Chipping Norton School, was underused. Then, in the winter of 2001-2, seven acres (3 ha) of it were planted up with trees, mostly native broadleaf species, to create “a community wood for the townspeople to walk in and enjoy.”

Being  next to allotments there are established garden throw-outs amongst the hazel, beech and wild cherry.   Yesterday coming into flower were a few garden muscari (Muscari armeniacum), garden crocuses and primroses including the garden hybrid, Primula x pruhonicensis.  There were also lots of snowdrops, on which I saw my first honeybee of the year.   Given that all the trees were introduced, but thankfully native, another appropriate introduction might be the rather rare native, Muscari neglectum, which is found only a few miles away in Charlbury, where the habitat is similar.

The main interest though for me are the  few scattered bee orchids, surprisingly amongst hazel scrub, and a couple of plants under a young beech, so there may have been plants there 20 years ago when the woodland was created.   One of those last year, identified by Rachel, one of the dedicated volunteers, was a wasp orchid (Orchis apifera var trollii), and there are leaves there this year, but maybe not the same plant. 

Atypical bee orchid habitat

The reserve is suffering from overuse by dog-walkers however; despite an entrance sign asking for dogs to be kept on a leash, it was ignored by all those I saw, and as a result the paths and glades are being flattened.    There was also very little birdlife about.   Its a universal problem sadly.

Saturday 8 August 2020

Fruit Set in the Greater Butterfly Orchids at Christmas Common

Back in March I thought that the coronavirus restrictions might impede or worse, lead to the cancellation of the greater butterfly orchid study I am undertaking at Christmas Common, but in the last week I was able to count the number of fruits on the plants that flowered in early June.   This was the final act of the year, so this year's data has been collected without interruption.

Fruit set this year was higher than in any of the previous 3 years at an average of 47%, the number of individual flowers that were pollinated.   Night-flying moths are the pollinators, though in 10 years I have never managed to see a moth actually pollinating a plant.  A typical flower spike has 10 to 15 flowers, opening up first from the bottom of the spike.   Flowers in the middle of the spike are more likely to be pollinated than those at the bottom, and especially those late opening flowers at the top.

A few of the plants simply wither away after flowering but I have no idea why and there are no obvious differences to the majority.

I am all set now to analyse the data during the winter, though my next trio to the site will be in November to cut back bramble, and check the plant labels.   Of particular interest will be to see what inferences can be made about the impact the very dry conditions in July and August last year and in May this year had on plant numbers, and flowering behaviour.

Wednesday 3 June 2020

Greater Butterfly Orchid Study - Fourth Year

The lockdown restrictions were eased just in time to allow me to travel down to Christmas Common in the Chilterns to count and measure the greater butterfly orchids there, for the fourth successive year.   The plants are in two enclosures to keep out deer, and in one of those enclosures - the South enclosure, which covers around 200 m2 - all the plants are individually marked once they appear.   So far 330 plants have been marked, of which 253 either flowered or had leaves above ground this year.

Part of the South enclosure
In this enclosure there were 28 flowering plants, 159 had a single leaf, and 66 had 2 leaves.   All the flowering plants were either extant in 2017, the first year of the study or first appeared in 2018.  The number of flowering plants increased by 27% on 2019, but then that was a year when snail damage had a serious impact.   Indeed the numbers are still well down on 2018, and the very dry conditions in late summer 2018 and 2019 also had an impact.   In the North enclosure and outside the enclosure there were a further 38 and 11 flowering plants respectively, bringing the overall total up to 77.

A plant in the North enclosure
 The population structure is changing.   Lots of new plants are emerging, but they are not progressing to robust, flowering plants because of damage by snails and climate factors (which I shall try to quantify).   In the North enclosure orchids are increasingly being crowded out by dog's mercury, cleavers and nettles.

For the first time all the plants outside the South enclosure were marked and measured.   As this area is unfenced, the impact of deer, (muntjac in the main) could be seen.  In addition to the 11 flowering plants the stems of a further 3 were chewed of by deer.  

Several measurements were made on each of the flowering plants in the South enclosure - height, inflorescence, number of flowers and width of lowest leaf.   Photographs of a single flower from each plant were taken so that the flower dimensions and spur length can be calculated, though this is still to be done because it is time consuming.
Plant #205
Plant #205

Plant #205 - Length of spur measurement
With 4 years of data tracking plants individually there is lots of analysis to be done:
  • climate relationships with flowering, new plant generation and plant losses
  • morphology of flowering plants
  • repeat flowering
  • anything else that takes my fancy.
On site there is only one other orchid species, a very few common spotted orchids dotted around.

Common Spotted Orchid

Saturday 23 May 2020

Short term extremes of weather and the impact on plants

Covid-19 must be serious; lack of rain for at least a month has not even been mentioned in the newspapers, and this in a country obsessed by the weather.  This month we have had just over 1 mm of rain so far; its a drought!

I went to my nearby meadow at the beginning of the week, and where a couple of weeks ago there were 4 butterfly orchids in bud out of a total of around 25 plants, the dry weather has had a significant impact, shrivelling up the buds and the leaves.   There won't be any flowers this year, and given the state of the leaves they are unlikely to produce sizeable enough tubers for next year's plants to thrive.   I fear that this relatively short spell of continuous dry weather might well have seriously impaired this little population of orchids for two to three years.

On Skye I looked at correlations between orchid populations and climate parameters.  Now, in a more comprehensive study that is now in its fourth year, the landowner and I are undertaking a study of the population dynamics of butterfly orchids in a farm in the Chilterns.   I have carried out some climate comparisons, taking monthly data, but in the analysis I might in the past have missed the importance of some short term extremes such as the current drought.  Were it to rain heavily for a couple of days later this month the dry conditions day after day will be masked in the monthly total figure,  so in future analyses I am going to incorporate the number of days when no appreciable rain fell.  Heavy rain on a few days, with the ground drying out between bursts, is much less helpful than regular rainfall.

Meanwhile our study greater butterfly orchids in the Chilterns are just beginning to flower and I shall undertake a comprehensive count early next week, now that travel is less restricted.

I have been regularly moth trapping, and after a very slow start at the beginning of May, 2 nights ago I had 42 species (59 species year to date) several of which I had not seen before.   

There is a blackbird nesting in the honeysuckle along my fence in the garden.

Monday 27 April 2020

Enjoying the Lockdown

I think I have adapted well to confinement.   Staying close to home therefore (no more than 2 to 3 km away), the flowering plant count is now up to around 100 for April, and now includes Adder's-tongue fern, (Ophioglossum vulgatum) in a calcareous field at Coldharbour, which is I think a first for the Hook Norton hectad, but even more excitement came from finding 2 plants of Herb-Paris (Paris quadrifolium) for which there are a scattering of old records, but super to see, and one of my favourites.   I would not have been any near where I found it in any normal year, and there are still a few more corners nearby that I plan to explore, so there might be further delights to find

Herb Paris

Adder's-tongue Fern

I did stretch the rules a bit on Friday, but don't think I transgressed.  I drove 8 km to Wolford Wood, but then spent several hours there.  Lots of Early purple orchids (Orchis mascula) and of course bluebells, bluebells and yet more bluebells.

Early Purple Orchid

Early Purple Orchid
Meanwhile moths seem to have gone into lockdown.  The dry weather allowed me to put the trap out on 4 occasions in April but the counts have been derisory.  So far only 12 species year-to-date compared to 16 in 2019.