Polypogon arrives in Aberystwyth

Polypogon viridis has arrived in Aberystwyth. An established colony (c. 50 plants) is growing on a paved area adjacent to the Alexandra Road / Rheidol Retail Park roundabout (SN58608167). Given the size of the colony I presume that it actually arrived last year so may already have been noted by other recorders. It also occurs at the University's Fron Goch farm where it currently grows only inside one of the abandoned glasshouses (SN60618259).

Picnic Island

Yesterday evening I visited a place called Picnic Island. A small rocky promontory cut off by the railway on the north bank of the Dyfi Estuary overlooking Ynys-las. Half an hour poking around revealed some nice species in the unpromising looking mown picnic area including Trifolium striatum, T. micranthum, Koeleria macrantha, Sagina apetela, Aira caryophyllea and Aphanes arvensis.

Trifolium striatum,
SN626962, VC48

Trampled ground by the path to Penhelig revealed a single plant of Catapodium marinum, lots of Trifolium arvense and Origanum vulgare. Just above high water in an overhang of the cliff two plants of Asplenium obovatum were flourishing.   

Asplenium obovatum & Umbilicus rupestris,
SN626962, VC48

Off now to the National Botanic Garden of Wales to prepare for tomorrow's BSBI meeting.

Circaea alpina

Yesterday evening I took a trip up the Llyfnant Valley to a gorge on the Ceredigion Montgomeryshire border where Circaea alpina can be found. Recent (post 2000) Welsh records of this rare species are from the Llyfnant site and, according to BSBI Maps, Caernarfonshire and Brecknockshire (though recent records are not listed in the county rare plant register). Two historic sites for the species in Merionethshire haven't been updated for some time and there are a number of  (doubtful?) records for Montgomeryshire on NBN Gateway but not BSBI Maps.  

Circaea alpina,
Llyfnant Valley, SN7596, VC46

Having seen the plant in situ (though not yet in flower) I carried on to Corris; one of the historic Merioneth sites. No luck here but I was running out of light and didn't cover much of the site so there's still potential.

Survey & Oxalis

Recently I spent a week pootling around the Aberystwyth district trialling my new protected environment weed survey and collecting samples of Oxalis section Corniculatae and Cardamine of the flexuosa group. After a number of false starts I'm now fairly happy with the survey protocol. It has become much more complex but it should allow me to:

• Define the weed community of the protected environment
• Relate the internal community to that of adjacent external communities   
• Differentiate niche communities such as pots and cracks 
• Describe the seasonal variation within these communities

My living collection of Oxalis and Cardamine is growing and I should soon have enough to begin my screening using molecular markers and cytological techniques. With any luck this will allow me to better define taxonomic units and slot them in to global studies and work being conducted by other botanists. Before all of this I thought I'd post a few of the most recognisable Oxalis taxa.   

Firstly the deep purple Oxalis corniculata var. atropurpurea. This taxon is normally very distinctive due to its colouration though there seems to be some variation partly due to moisture and light.

Oxalis corniculata var. atropurpurea,
abandoned glasshouse,
 Fron Goch University Farm,
SN 60602 82591, VC46

Second the smallest species: O. exilis. Less variable than other taxa, normally the most prostrate and often growing in tight mats its leaves are always a fresh bright green and its flowers are borne singly.

Oxalis exilis, abandoned glasshouse,
Fron Goch University Farm,
SN 60602 82591, VC46

Oxalis exilis, abandoned glasshouse,
Fron Goch University Farm,
SN 60602 82591, VC46

Lastly possible Oxalis dillenii a much scarcer species. It was abundant in a single abandoned glasshouse at Llanbadarn. Obviously larger, more upright, its flowers are produced in small corymbs and its leaves have a slightly bluish tinge.

Oxalis dillenii?, abandoned glasshouse,
 Llanbadarn Campus, SN 60607 81092, VC46

Oxalis dillenii?, abandoned glasshouse,
 Llanbadarn Campus, SN 60607 81092, VC46

Hopefully I'll have more detailed information as my research progresses over the next few months. 

Urtica membranacea

The seasonal visit to EGG, this year in Liverpool, was appended with a short stopover at Ness Botanic Gardens. The purpose of this visit being the collection of Oxalis and Cardamine plants to form the basis of my initial taxonomic study. Our tour of Ness' glasshouses and polytunnels was assisted by Tim Baxter, the garden's botanist. In the last polytunnel of our tour my supervisor John Warren spotted a strange nettle growing in a number of the large planters; a nettle with a crucifix of short purple racemes of male flowers atop a small, annual and almost stingless plant. After some fruitless discussion as to its identity, I bagged two of the four plants for later determination. Flora Europea revealed the plants to be Urtica membranacea, previously known as U. dubia. The first UK record of this southern European species was made in Warwick in 2006 and there have been a scattering of other records across the UK in the intervening years. The species has previously been recorded in Pensby about five miles further along the Wirral.

Urtica membranacea, Ness Botanic Gardens,
VC58, SJ 29727 77557, 01/04/15

Urtica membranacea, Ness Botanic Gardens,
VC58, SJ 29727 77557, 01/04/15

.      

X Agropogon robinsonii & others, National Botanic Garden of Wales

A visit to the gardens during last week's heatwave roved productive with a couple of cudweeds, a spurge and a intergeneric grass hybrid.

Polypogon viridis is now among the most common grasses around the propagation glasshouses at the gardens. Reasoning that this increased my chances, I set to hunting for its intergeneric hybrid with Agrostis stolonifera: X Agropogon robinsonii. Despite somewhat conflicting literature including what appears to be an erroneous description in Sell & Murrell I managed to find a single putative hybrid plant. Examination back home under the microscope showed a mixture of characters of the two parent species and intermediate character states. The anther length (c. 1.1mm) being closer to A. stolonifera and much longer than that of P. viridis (c. 0.6mm). The lemma and palea resembling those of P. viridis both in shape and relative length (almost equal). The glumes having sparse scrabidity from P. viridis but more pronounced bristles on the keel from A. stolonifera. The end of the ligule  being ciliolate as in P. viridis but the overall structure of the tiller more like that of A. stolonifera. Given these features I'm happy to call the plant X Agropogon robinsonii though it will probably need to be sent off for confirmation. As far as I can tell this hybrid has previously only been recorded four times in the UK (all but one in the Channel Islands) and once in France. Given the rapid spread of P. viridis in recent years it may be that other people have found this hybrid recently. If not it is probably worth keeping an eye out for wherever P. viridis occurs.

***Note***  Now 'cautiously confirmed' by Tom Cope at Kew as the fifth ever record of this taxon. The 'cautious' prefix having to do with some previously confirmed material of this this taxon having been redetermined as pure Polypogon and the fact that the only other available material (a Guernsey collection from 1997 by Rachel Rabey) is much larger and more distinctly intermediate between the parent taxa than NBGW material. On balance however the male sterility and persistent glumes were, according to Tom Cope, enough for the 'cautious confirmation'. Confirmation is with thanks to Richard Pryce, Arthur Copping, Tom Cope and Rachel Rabey.      

X Agropogon robinsonii, culm,
NBGW, SN 52105 18410

X Agropogon robinsonii, habit,
NBGW, SN 52105 18410

X Agropogon robinsonii, tiller,
NBGW, SN 52105 18410

X Agropogon robinsonii, inflorescence,
NBGW, SN 52105 18410

Now cudweeds, the most interesting of which was a single plant of Gnaphalium luteoalbum growing on gravel between two propagation glasshouses. This species is restricted as a native to a few sites in the south of England and occurs as a scattered casual elsewhere but appears not to have been recorded in Wales post 1930. Despite fairly extensive searching I could not locate any more plants suggesting that this species may have only just arrived at the gardens.

A more frequent cudweed: Filago vulgaris was abundant on on parched ground around the science block. Bringing the cudweed total for my trip to three including the common Gnaphalium uliginosum.

Gnaphalium luteoalbum,
NBGW, SN 52138 18412

Filago vulgaris,
NBGW, SN 51970 18239

Finally a spurge: Euphorbia stricta is very local as a native being restricted to the open ground in woodlands around the southern Welsh borders. At the gardens it grows in abundance behind a single polytunnel. I don't know if it arrived at the site of its own accord as a casual or, more likely, either as a horticultural species or as part of the Garden's Welsh Rare Plants Project.

Euphorbia stricta,
NBGW, SN 52053 18410

Greater spotted woodpecker, dead from flying into glasshouse,
and a calliphorid fly, NBGW

Spring: Hectic Catch Up

Spring has passed and I have not produced a single post. So here, cobbled together without any real narrative, are some of the pictures I've amassed over the past months. 

For continuity we return where winter left us in the Aberystywth University Vice-Chancellor's garden where, in March, a strange parasite pokes artificial looking purple and white buds through the leaf-litter. Lathraea clandestina is an alien that mostly occurs in gardens and is scattered across the UK. In Aberystwyth it grows at the base of a Metasequoia glyptostroboides a species that is not thought to be a host though the population is not far from its more generally favoured Salicaceous hosts. 

Lathraea clandestina, buds,
SN 59354 82044, March 2014

Lathraea clandestina, flower,
SN 59354 82044, March 2014

And so spring continued and I briefly left the safety of Aberystwyth for a trip north-east to The Ecological Genetics Group Conference in Newcastle. The second day of the conference saw us escape the confines of the hotel and head out to the remains of an old open cast coal mine near Hauxley. It had, as is often the case with old mine workings, been turned into a nature reserve featuring scrapes and hides. The botany was limited and despite the visit being lead by John Richards (of which more later) not a single Taraxacum was investigated. One very large species that was new to me and admired by all for its architectural qualities was Dipsacus laciniatus an uncommon alien of waste places.     

Dipsacus laciniatus, Spring rosette, 
NU 28323 02379, 14/04/2014

Dipsacus laciniatus, Old heads, 
NU 28323 02379, 14/04/2014

Shortly after returning from Newcastle I travelled to North Wales with Andy Jones for the BSBI Taraxacum Workshop. With events like this somewhere after the fifth or sixth micro-species and its accompanying explanation you begin to realise that you're fighting a loosing battle, characters and names blur, until, eventually, most that remains is an mental soup of undifferentiated Taraxacum. However John Richards descriptions were informative and often amusing. A favourite statement, acquired from the Danish Taraxacologist Hans Øllgaard, being 'ah, lovely, pedagogic material'. Pedagogic in this sense apparently meaning 'exemplary'. The etymology of which I presume is related to the specimen being perfect for demonstrating the characters of the species. Anyway despite the information overload I did pick up a few species. Taraxacum britannicum a section Celtica species with small involucres with dark tips and erect or adpressed bracts in bud. Taraxacum argutum a section Erythrosperma species with closed capitula and inrolled reddish ligules. Taraxacum insigne a section Ruderalia species with long spoke-like bracts held at right angles to the bud. So three of the 230 or so UK Taraxacum species are now part of my botanical repertoire which is a start I suppose...

Taraxacum britannicum, Treborth, VC49, 24/04/2014

Taraxacum insigne, Aberffraw,
VC52, 25/04/2014

The second Taraxacum day began with a visit to Newborough Warren. Some amusement was had when John Richards initially misidentified what he soon realised to be 'his dandelion' Taraxacum richardsianum. A few plants of this section Nervosa species with its spotted leaves grew in a sandy scrape beside the path. As we picked our way through a minefield of dog poo that spreads out from the car park our Taraxacum list grew with most species turning out to be new county records.

Huddling Taraxcicologists, Newborough Warren, VC52, 25/04/2014

Taraxacum richardsianum, Newborough Warren, VC52, 25/04/2014

As we eventually left the path and headed onto the dunes it began to rain and with lunch time fast approaching it was decided that retreat was the wisest option. Before we turned back we added a few delicate Taraxacum sect. Erythrosperma species including the widespread T. oxoniense with its pale bordered bracts. Other spring sand dune flowers were also in abundance including Vicia lathyroides and the dwarf Valerianella locusta var. dunensis. 

Taraxacum oxoniense, Newborough Warren, VC52, 25/04/2014

Vicia lathyroides, Newborough Warren, VC52, 25/04/2014

As we headed back I made a last effort to find one of the target species for our visit to Newborough. Taraxacum palustre a member of section Palustre and one of the more easily identified Taraxacum species. Local and closely associated with damp calcareous situations Anglesey is one of its strongholds and there were old records for Newborough. Searches in the tall vegetation during the morning had failed to reveal anything but in eventually in short grazed turf I and another member of the party found two small populations. The majority of the plants were clinging to tussocks of Schoenus nigricans. A particullary picturesque one of these showed nicely the closely appressed bracts and undivided leaves that make section Palustre 'unmistakable' in dandelion terms. 

Taraxacum palustre, Newborough Warren, VC52, 25/04/2014

Our last stop was a seemingly unremarkable lane leading up from the edge of the Menai Straits at Foel Farm. By this point I had seen far too many Taraxacums to assimilate any related information. As we were about to leave Richard Price spotted a single plant of Fumaria purpurea in the hedge bank. It turned out to be a noteworthy end to the day as the species had not been recorded from the county for many years.

Fumaria purpurea, Lane near Foel Farm, 
VC52, 25/04/2014

The day after I returned from North Wales and with Taraxacums still plaguing my every waking thought I shipped out to Preston Montford in Shropshire to assist on a University field course. It was a busy week of varied tutorials covering ecology, geology and land-use with eighty undergraduates. Plants had their place and even took centre stage on a few of the days and we saw a few interesting species along the way.

John Warren demonstrates Equisetum spore movement,
The Ercall,  SJ 64425 09556, 29/04/2014

The first afternoon was spent in Ashes Hollow, in a small stream that flows down the east flank of Long Mynd into Little Stretton. While not strictly botanical I did get to indulge my intermittent interest in Coleoptera when a large and distinctive looking Staphylinid with a fine golden pubescence flew into the side of my head. Later research revealed it to be Ontholestes tessellatus a widespread but not common species associated with dung and carrion.  

Ontholestes tessellatus, Ashes Hollow,
Shropshire, SO 42625 93068,
Coll: 27/04/2014

Emperor Moth (Saturnia pavonia),
Barrister's Plain, Shropshire, SO 42600 92750, 27/04/2014

Returning to the minibuses atop Pole Bank John found Teesdalia nudicaulis growing on a knoll by the car-park. This diminutive Crucifer with its neat little spathulate leaves grows in very dry nutrient poor places and is uncommon in the West.  

Teesdalia nudicaulis, Pole Bank,
Shropshire, SO 41741 94305, 27/04/2014

Later days of the trip included visits to a number of other small hills south though Shropshire as well as the Fens to the north. On the penultimate day we visited the Iron Age fort of Nordy Bank in the Brown Clee Hills. The impressive earthworks atop the small hill supported some nice species including Moenchia erecta, Trifolium micranthum and many little Taraxacum sect. Erythrosperma that were still a mystery to me. 

Moenchia erecta, Nordy Bank,
Shropshire, SO 57469 84752, 30/04/2014

On the last day we climbed the Stiperstones to look at heather cycles and moorland management for grouse. We passed through some nice fields of upland acid grassland dotted with dewy Viola lutea. In the patchwork of managed heather we stopped to set up basic quadrats and record the handful of species present among which were flowering Vaccinium vitis-idaea and the bronze shoots of  Melampyrum pratense.   

Viola lutea, Stiperstones,
Shropshire, SO 36285 98816, 01/05/2014

Vaccinium vitis-idaea, Stiperstones,
Shropshire, SO 36298 99357, 01/05/2014

So that's spring. Hopefully I'll manage more regular updates for the remainder of the season...