Monday, 30 September 2013

Glasshouse Aliens

I've been sorting through my specimens from my early summer survey of botanical garden glasshouses. Among the many unidentifiable seedlings there have been a few species of interest that I have managed to identify. There is a particular satisfaction using a range of piecemeal sources to determine the identity of a plant not included in Stace though it is often impossible to be certain of a determination at the species level of a plant that could have originated anywhere in the world. Below are a selection of taxa that I have at least determined to genus.

Firstly an easy determination, Solanum chenopodioides, which I found growing in a disused propagation glasshouse at RHS Wisely. The vernacular name for this species is Tall Nightshade and it was large forming a messy bush with tough, woody stems. A dense covering of retrose hairs all over is another character of this species. Originating in South America this species is a very local casual in the UK.              

Solanum chenopodioides, Fruits,
RHS Wisely, TQ 06498 57977, April 2013

Parietaria officinalis grew in abundance in many of the Edinburgh glasshouses. This larger relative of the common P. judaica has longer leaves and also differers in characters of the flower and fruit. Very locally naturalised in the UK this species originates from eastern Europe.   

Parietaria officinalis, Edinburgh Botanic Gardens, May 2013

Growing amongst moss intended for orchids and cycads was a small glandular plant with a pocket shaped yellow flower. Research revealed it to be Calceolaria tripartita a South American weed of damp mossy habitats. This species is not listed in Stace but is mentioned in Clement & Foster's 'Alien Plants of the British Isles' as having occurred in the UK a couple of times.    

Calceolaria tripartita,
Edinburgh Botanic Gardens, May 2013

A frequent weed in the public glasshouses at Edinburgh was Fuchsia procumbens. Very different to the large Fuchsia magellanica familiar from hedges and gardens this species revealed itself as a Fuchsia by way of its succulent, barrel-shaped fruits quite similar to those of the familiar species.  

Fuchsia procumbens,  Edinburgh Botanic Gardens, May 2013

In a wet patch at the edge of the Eden Mediterranean Biome there was plentiful Polypogon viridis. I have only recently become acquainted with this grass which, according to the floras, is very similar to Agrostis stolonifera but looks subtly different in practice. I found it growing near Holyhead Port (VC52) and it has recently colonised Bangor (VC49) where it is now abundant along the edges of some streets.

N.B. I've just found this at the NBGW growing beside a track and also in a disused glasshouse. I've taken the opportunity to compare it with Agrostis stolonifera under the microscope. The key difference is in the comparative lengths of the lemma and the paella, equal in P. viridis and with the paella shorter in A. stolonifera. The glumes of P. viridis are hispid all over while those of A. stolonifera just have a few relatively large bristles toward the end of the keel. The pedicels of P. viridis are also hispid while those of A. stolonifera are smooth. John Poland's vegetative key notes the ciliolate margin to the end of the ligule and this shows up nicely on the P. viridis while the ligule of A. stolonifera is smooth. These notes are based on a couple of plants from one population so may not apply to all plants particularly given the variability of A. stolonifera. Now to find the hybrid...

Polypogon viridis,
Med Biome, Eden Project, April 2013

As mentioned in a previous post the flora of the Tropical Biome at Eden was rather confusing. One relatively easy species to determine was Digitaria ciliaris. This, the most tropical of the three Digitaria species naturalised in the UK, is distinguished on characters of the glume and lemma.

Digitaria ciliaris,
Tropical Biome, Eden Project, April 2013

A final plant also from the Tropical Biome at Eden, this time one that has eluded final determination. Clearly a member of the Urticaceae it was also present in the tropical house at RHS Wisely. My best guess as to its identity is the genus Boehmeria but trawling the internet has failed to help choose from the 100 or so species within this genus. So, if you happen to know its identity please do comment.

N.b.- Having DNA barcoded my specimen of this plant I can now say I was barking up the wrong tree looking in the Urticaceae as it came back as a species of Acalypha in the Euphorbiaceae. This large pan-tropical genus derives its name from the Greek word for nettle (akalephes) in reference to its often nettle like leaves making my previous misidentification a little less embarrassing.

Acalypha sp.,
Tropical Biome, Eden Project, April 2013

Monday, 23 September 2013

Coastal Walk, Aberystwyth to Borth

On a sunny Sunday at the end of August I decided to be active for once and walk along the cliffs to Borth. After Constitution Hill and the holiday atmosphere of Clarach I found a heap of waste from the caravan site with a nice assemblage of ruderal weeds. The most noticeable of which were a variety of large 'Chenopodiaceae'. Most of these turned out to be Chenopodium ficifolium mixed with C. rubrum, C. album and Atriplex patulaC. ficifolium is not a very common species in the west of Wales and I had previously only seen it once in the area, in municipal planters on the Aberystwyth promenade earlier this year. Those plants had been diligently weeded before they had a chance to mature so it was nice to see some fully grown specimens.    

Chenopodium ficifolium,
Clarach Bay, SN 58631 84392, August 2013

Chenopodium rubrum,
Clarach Bay, SN 58631 84392, August 2013

A little further on I scraped around on a parched area of short grass in the hope of finding Trifolium subterraneum. I quickly found a large number of recently germinated small Trifolium plants with small hairy leaves. I'm still not sure as to their identity as I'm unclear on the phenology of Tsubterraneum. Hopefully a revisit in a month or so should reveal their true identity. 

(Probable) Trifolium subterraneum,
Coastal hillside N. of Clarach Bay,
SN 58773 84733, August 2013

Returning to the coastal path large stands of Lathyrus sylvestris were showing their last few flowers and an abundance of chunky pods. This mostly coastal species is particularly fond of soft cliffs in the west. Also scrambling around on the cliffs were a few old plants of the invasive Lycium barbarum. This oriental species is the source of the goji berry a recent 'wonder food' craze.  

Lathyrus sylvestris,
Cliffs S. of Wallog,
SN 58917 85514, August 2013

Lycium barbarum,
Wallog, SN 59021 85720, August 2013

Arriving in Borth I had an hour or so before my train back to Aberystywth so spent a while peering into gardens and bits of waste ground along Borth's only street. Not much of note was apparent but a I took a final photo for the day of the small pallid flowers of Malva neglecta growing in someone's front garden.

Malva neglecta,
Borth Main Street, SN 60 89, August 2013 

Friday, 20 September 2013

Western Scotland

At the end of July my girlfriend and I set off on an ill-fated holiday to the Isle of Skye. We'd hired a car and the plan was to drive up at a leisurely pace and camp wherever we fancied. As it turned out the weather was not in our favour and we soon ran out of both steam and money and retreated south. As a result there wasn't much opportunity for botany.

Our first stop on the route north was the shores of Loch Lomond. A large patch of the common hybrid Stachys x ambigua was in full flower. Though not visible in the picture below the slightly stalked lanceolate leaves distinguish it from either parent. The delicate heads of Carum verticillatum were scattered about by the water with their distinctive whorled leaves.

Stachys x ambigua, 
W shore Loch Lomond, July 2013,

Carum verticillatum, 
W shore Loch Lomond, July 2013,

A little further north we stopped on the expanse of Rannoch Moor to poke about in the stony tarns. Lobelia dortmanna was flowering, its heads swaying about in the breeze. I puzzled over some very small Ranunculus flammula type plants in the hope of R. reptans or at least the hybrid but eventually gave up on them completely. Back by the car there were a few plants of Rumex longifolius. A common species in Scotland but one I'd only seen a couple of times before.

Lobelia dortmanna,
Loch Ba, NN 31 49, July 2013,

Rumex longifolius,
Near Loch Ba, NN 31 49, July 2013,

A short stop for lunch on the way down toward Glencoe provided the last of the dry weather and a nice sighting of a couple of Scotch Argus butterflies flitting about in a boggy patch by the river.

Scotch Argus (Erebia aethiops),
Near Glencoe, July 2013

The one full day we spent on Skye was so grim that we hardly dared leave the car. The one Skye 'speciality' that can be seen almost without leaving the car is the hybrid horsetail Equisetum x font-queri at its first know UK locality in a roadside ditch below the glowering cliffs and stacks of the Storr. This hybrid between E. palustre and E. telmateia has since been found in a number of other places in the UK. 

Equisetum x font-queri,
Rigg, Skye, July 2013

Equisetum x font-queri,
Rigg, Skye, July 2013

Wednesday, 11 September 2013


Time now for a few pictures of plants I've seen while going about my daily business in and around Aberystwyth. Firstly an alien that I originally noticed this spring. Tall with linear leaves it was scattered around a car park near the railway station. When it came into flower and was immediately recognisable as Narrow-leaved Ragwort, Senecio inaequidens. This species originates in South Africa and is thought to have arrived in Europe as a hitch-hiker in soil on military equipment during the Second World War (1). It is now spreading in the UK seemingly associated with railways with the only  previous Cardiganshire record from the Borth area. It seems well established in the car park where this picture was taken but must have only arrived last year and may well spread through the town over years to come.         

Senecio inaequidens, Aberystwyth,
SN 58561 81570, June 2013 

Aberystwyth Castle sits on a small promontory at the centre of the Aberystwyth seafront. The crumbling walls are covered in flowers including Spergularia rupicola and Ononis repens but the most interesting plant is in my opinion is Asplenium marinum. Usually a species of natural sea-cliff crevices this is the only site where I have seen it growing on mortared walls.  

Asplenium marinum, Aberystwyth Castle,
June 2013 

On gravelly ground inside the castle walls Trifolium scabrum grows in abundance. This species is one of the more local clovers growing mainly on dry, rocky ground near the sea in the south of the British Isles.

Trifolium scabrum, Aberystwyth Castle,
June 2013 

Back again to the carpark near the station. I had been keeping an eye on a single large grass plant growing in  a municipal bed along with a few plants of Senecio inaequidens. A few weeks ago it began flowering revealing itself to be the relatively common casual Echinochloa crus-galli.

Echinochloa crus-galli, Aberystwyth,
 SN 58590 81637, Sept 2013

(1) - European Commission. (2004). Alien species and nature conservation in the EU. The role of the LIFE program. Office for Official Publications of the European Communities, Luxembourg.