Graham’s Vc 5 updates

Yet more from VC5

This one is by way of thank you to Clive for all his expertise and skills in the determination.

Just before lockdown in early March I was meeting friends from Wales at Taunton Racecourse; part of my mind was considering the possibility of Poa infirma in the car park or various rings and the track itself. Hence in pocket the GPS, camera and note book.

In deepest darkest Taunton, taking the turn outside Sainsbury’s towards the racecourse the traffic island had a very characteristic strip of light green.

You can clearly see the lighter green strip on the right of the picture? Now there are other reasons for a light green strip, water logging, herbicide drift, and just plain old fashioned moss. Clearly this had to be investigated and there was parking to spare although I have some sort of recollection that double yellow lines have an important meaning. The ensuing horns seemed to stop when I held up my GPS and notebook for some reason. Samples secured, I was reasonably certain they were Poa infirma but had a look at them the next day under the microscope to measure the anthers. This was where my confusion started as the anthers were a fraction on the large size for P infirma being over just over 0.6mm. Poa infirma is usually found to have anthers in the range 0.15-0.4mm and P annua 0.6-1.1 (BSBI Grasses of the British Isles by Tom Cope and Alan Gray). In practice the difference between the two is usually very clear even in the field. P. infirma anthers very difficult to see and require a lens, P annua visible to naked eye and much longer than wide.

These despite being over 0.6mm were not P annua anthers.

This is your typical size and shape of P infirma anther from previous years recording.

This was the anther from Taunton specimens, clearly shape of infirma but on large size. A call to Clive who has previously recorded the hybrid and he was only too willing to help. Clive found much deflated pollen that did not stain with aceto-orcein and some full pollen that did stain. Given the presence of sterile pollen and size of anthers the conclusion was made that this is the hybrid between annua and infirma.

It’s perhaps interesting to note that locally to me Poa infirma is very easy to find throughout Minehead but despite taking multiple samples there has not been any suggestion of a hybrid.

My thanks again to Clive, his experience with the hybrid he found in Wiltshire and his expertise in extracting pollen from the anther and staining techniques were essential.

The best picture of Poa infirma for those who have yet to see it are by Fred on the Somerset Rare Plant Register where it remains at the moment although it is now Not Scarce in VC5 and VC6 from diligent searching in last few years by many Somerset botanists.

This is the BSBI map for current distribution of Poa infirma, very hard to say how overlooked it remains in VC5 but certainly much better recorded than even a few years ago.

Best wishes

Graham

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Ranunculus Subgenus Batrachium

Once again I might just raise more questions than answers on this one but it’s an issue of accuracy of recording so I think worthwhile.

The River Aller is not a long river, four monads just about covers it and then it joins with the Horner stream just before Bossington and then short distance to sea.  Ranunculus fluitans is on the Rare Plant Register as scarce in VC5 so an important plant. At the start of River Aller   R fluitans is recorded after that either R penicillatus or R penicillatus subs pseudofluitans is recorded and indeed in most cases both are recorded. Now this is a stream that in most of its length is just 2-3 metres wide, fairly fast flowing and instincts suggest only one Water Crowfoot is likely to be present (but not certain). Indeed in the top monad where R fluitans is recorded the length of leaf is long , well in excess of adjacent node and coupled with few divisions of leaf it has not unsurprisingly been recorded as R fluitans in past. By the end of that monad and indeed probably only 70m from the longer leaved R fluitans there does appear at first glance a change of taxa which seems to continue for next three monads and as already said recorded variously as R penicillatus and/or R penicillatus subs pseudofluitans.

Ranunculus fluitans in River Aller.

Only one option, have a closer look and to cut a long story short I did not have the skills to make a determination that I was certain of.  Richard Lansdown was very obliging and took a look at a good flowering sample; indeed a voucher from the patch where the longer leaved R. fluitans seemed to have a change of jizz to shorter leaf was sent to him

This is the summary of his email;

Hi Graham,

I have had a look at your plant. The leaf divisions would make it R. fluitans. This is an excerpt from a forthcoming key (not mine), I think that the caveat fits.

Large plants, robust, laminar leaves absent, capillary leaves exceedingly long, fleshy, subparallel, final segments less than 50, petals 6-12, receptacle glabrous……………………………………………………. R. fluitans Lam

Remark: Plants with 1 or 2 deviating characters should be identified as ‘R. cf. fluitans’. They indicate historical Introgression. Plants with more deviating characters are regarded as R. fluitans hybrids of which the second parent species is indeterminable.

I would say that yours has the receptacle which is not glabrous, I don’t think that the leaves are particularly long or very fleshy but they definitely have fewer than 50 ultimate segments. So yours could probably be called R. cf. fluitans or possibly a R. fluitans hybrid.

I think that this key has real honesty and suspect that it will make decision-making easier. However, most populations will not be named to a species, so many people will not be happy.

Best wishes

Richard.

So, using Richards’s guidance I have looked at all the River Aller Water Crowfoot and it is looking like all the River Aller Ranunculus is in-fact R fluitans (or possibly a hybrid) despite some variation in leaf length. I did find Richard’s guidance on receptacle a useful feature.

Just one more photo.

Ranunculus fluitans receptacle.

A new key might well be worth the wait but equally I thought I would highlight some issues with this difficult taxon.  Examination can be done in the field and the photo shows the sparsely hairy receptacle (with a few carpels removed) of fluitans.  This is important character in Stace 4 key and the above sparsely hairy or indeed sometimes glabrous receptacle is one feature in separating fluitans from the densely hairy penicillatus,  The online Plant Crib is best for guidance on rest of the main features for identification.

Best wishes

Graham

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August in VC5.

This one missed last circular but I think it’s important we are all aware of it. Its Cotula coronopifolia( Buttonweed) found at West Sedgemoor SSSI in July by Steve Parker and Damon Bridge.

Cotula coronopifolia at West Sedgemoor July 2020.

This is first record for VC5, the first in VC6 was 2019 so if it’s spreading I would be interested in a little more detail of habitat please Steve? The next one is an old record in VC5, Calystegia sylvatica subs disjuncta.  Seems a reasonable record, fits the Stace 4 description but the question I ask is what is the difference between it and Calystegia pulchra x sylvatica (C x howittorium), it flummoxed me on re-finding it?

Any help appreciated, details as recorded, well pouched bracteoles, pink only on outside of corolla, corolla 6.2cm, stamens 28mm, leaves with rounded sinus, pedicels glabrous.

This one is from lockdown, now confirmed by our Hieracium referee Mike Shaw, author of the book Hawkweeds of South-east England, just published.

It’s grown in garden and usually found as an escape from April to July. Probably overlooked as this is the first record for VC5.

Hieracium scotisticum in April 2020 on wall

Best wishes

Graham

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July 2020 VC5 interesting records.

Particularly for those like me without a social media platform, here are a few of the highlights found so far in 2020.

This has to be up there in top spot. This is Orobanche rapum-genistae (Greater Broomrape) found by Richard Brentnall, not a botanist but a relation in Cumbria is and lent him; The Atlas Flora of Somerset by Paul Green, Ian Green and Geraldine Crouch. He noticed in the book a record for Orobanche close to his home in Brushford, went for a walk and found it.

Here it is right by footpath and under Gorse.

Close up of Orobanche rapum-genistae

Now the last record for this site, and that’s despite repeated searches, is by the authors of; The Atlas of Somerset, mentioned above, from May 1990. What a wonderful record and also thanks to Fred Rumsey for confirming the record.

Not much beats that but I really must repeat Sharon Pilkingtons record of Spergularia bocconei (Greek Sea-spurrey). A wonderful new record for Somerset.

The next record is not a stone’s throw from the Spergularia bocconei, a very large muck heap produced Chenopodium urbicum (Upright Goosefoot, now Oxybasis urbica in Stace 4).

Not a new record for VC5 but the last was in 1940. Thanks this time goes to John Akeroyd the BSBI referee for the genus for confirming it from specimen I sent him.  It’s on the Red list for England as “critically endangered” so should make the Rare Plant Register for Somerset. It’s possibly overlooked so perhaps worth noting a few of the features, complete absence of any red colouration, size and shape of leaf, acute lobes some of which are recurved. Well worth checking the local dung heaps!

Another one perhaps worth looking out for is this Coriandrum sativum (Coriander).

Found growing in gravel between wall and road in south facing position. The fruits are very distinctive.

Coriandrum sativum fruit.                         All for now best wishes  Graham

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July 2020 More news in VC5

Last year we had a SRPG meeting on Exmoor at Pinkery. One of the records on the day was a putative Euphrasia anglica x confusa. Now this is a rare hybrid, anglica is a diploid and confusa a tetraploid so hybridisation is infrequent and post 2000 this is only the 21st record for it in the UK on the DDb.

Chris Metherell, the Euphrasia referee, had a large backlog of specimens to determine from 2019 and apologised for the delay and only got round to it in June this year. The Euphrasia handbook (Eyebrights of the UK and Ireland by C Metherell and F J Rumsey) describes it as; a very distinctive plant, short with numerous branches and narrow leaves, it looks exactly like a bushy confusa but with sparse long glandular hairs.

The voucher is awaiting deposition in Taunton Herbarium.

The other Euphrasia from 2019 that might be of interest is a confusa x micrantha from the Porlock area. The Rare Plant Register for Somerset now has micrantha as extinct in VC5 not unreasonably as despite extensive searches the last record remains from pre 2000. This hybrid can be found in calluna habitat much the same as micrantha and its worth looking out for it.

Euphrasia confusa x micrantha

A voucher for this specimen is also waiting to be deposited at Taunton Herbarium.

Lastly and frankly a strange one. In 2017 Mike Wilcox visiting Exmoor recorded Myosotis stolonifera, vouchers were taken and confirmed with the appropriate referee David Welch. Indeed an article written by Mike was published in BSBI News as it was a noteworthy find so far from its northern range. It’s unclear why but Mike has withdrawn the record and had it deleted from the DDb. This may or may not be the end of the story but unless Mike publishes a retraction in a future BSBI News I think it’s worth highlighting this change to the flora of Somerset.

Best wishes

Graham