Wednesday, 22 May 2013

North Wales

A recent trip to North Wales presented the opportunity for some botanical tourism. Firstly though I took a wander around my mother's garden in Rhiwlas. Over the years I have filled the garden with a range of ferns and in spring  they are at their best, their croziers unfurling in fresh greens. Though not in any way uncommon  Hart's Tongue, Asplenium scolopendrium has to be one of the most beautiful ferns of spring. 

Asplenium scolopendrium,
Hen Ardd, Rhiwlas, VC49, May 2013 

Around the small pond at the bottom of the garden Rough Horsetail, Equisetum hyemale was poking its cones through the mess of Juncus and Agrostis. Elsewhere my Asplenium septentrionale continues to be munched to the edge of existence by the larvae of the Psychoides micro-moth and Gymnocarpium dryopteris continues its determined invasion of any part of the garden it has not yet conquered.    

Equisetum hyemale
Hen Ardd, Rhiwlas, VC49, May 2013

Leaving the garden I visited the woods at Padarn Country Park near Llanberis. Tufts of Hairy Wood-rush, Luzula pilosa were flowering on the woodland floor and the delicate panicles of Wood Melick, Melica uniflora drooped from the slate walls beside the path .

Luzula pilosa,
Padarn Country Park, VC 49, May 2013

Melica uniflora, Padarn Country Park, VC 49, May 2013

Further into the woods I revisited an orchid that I first found a decade or more ago: the Narrow-leaved Helleborine, Cephalanthera longifolia. This rarity normally favours calcareous habitats and its occurrence in these highly acidic woods is explicable only with reference to the multitude of small slate and mortar buildings scattered through these woods. The mortar from these leftovers of the slate mining industry has, over the years, leached into the surrounding soil enriching its pH enough for Cephalanthera to tolerate. Unfortunately my visit was a couple of weeks too early for the flowering season so the picture below is far from exciting.     

Cephalanthera longifolia, Padarn Country Park, VC 49, May 2013

My next stop was Penrhyn Castle, a local National Trust property. This nineteenth century mock-castle was the home of the Pennant family, owners of the lucrative Penrhyn slate quarries a couple of miles further up the Ogwen. The grounds of the castle are the only North Wales site for Southern Wood-rush, Luzula forsteri. This species, as its vernacular name suggests, has a southerly distribution though it was first described from Cardiganshire. It is closely related to L. pilosa but differs from this species in having the branches of the panicle ascendant rather than divergent.

Luzula forsteri,
Penrhyn Castle grounds, VC 49, May 2013

Leaving the mainland I headed across Anglesey to the dunes at Aberffraw. My main purpose in visiting this famous botanical locale was to search for its most famous (botanically at least) resident: Early Sand-grass, Mibora minima. This diminutive winter annual is, apparently, the smallest grass in the world. A rarity in the UK it has its headquarters on Anglesey with a few scattered populations elsewhere on the west coast. I was quickly rewarded in my search and soon realised that at Aberffraw it is abundant wherever the sward is open enough for it to establish.

Mibora minima, Aberffraw, VC 52, May 2013

As well as my target species the bare sandy areas in the dunes supported a rich assemblage of other winter annuals. The dwafed culms and congested heads of (probable) Bromus hordeaceus subsp. thominei were just poking through and the very pretty Sand Cat's-tail, Phleum arenarium was abundant.  

(probable) Bromus hordeaceus subsp. thominei, Aberffraw, VC 52, May 2013

Phleum arenarium,
Aberffraw, VC 52, May 2013

A final wander along the low cliffs to the south of the dunes provided a smattering of flowers. The thrift and primroses of the steep rocks giving way to Spring Squill, Scilla verna in the tight sward atop the cliffs.

Scilla verna, Aberffraw, VC 52, May 2013

Sunday, 19 May 2013

Wisley, Kew & Edinburgh

This post aims to zip through a few of the interesting plants from the remainder of my Botanic Garden tour. Spring being here I am rapidly amassing a backlog of material for this blog so I can't go into too great detail.

A couple of weeks ago I set off on my final set of lengthy train journeys and Travellodge nights. This was just as the cold weather finally departed making way for the delayed start of spring. This seemed to foreshorten the season meaning that when I arrived at RHS Wisely all the Magnolias, Rhododendrons and Camellias were all blooming together on Battleston Hill. 

Firstly a spider, Uloborus plumipes. This is the commonest member of a number of tramp spider species found in glasshouses (Wilson, 2011). Introduced by way of Holland and first recorded in the 1990's this species is now widespread in the UK as can be seen from this distribution map. This species was once thought to be parthenogenetic as very few males had been observed but this notion has since been dismissed  as males have been found in abundance higher up in glasshouses beyond the reach of most observers (Oxford, 2011).   

Uloborus plumipes, Tropical Propagation House, RHS Wisely, April 2013  

Outside scrambling among the mossy rockery I noticed a species that I have kept in mind while out in the mountains of Wales and Ireland. Epilobium pedunculare, Rockery Willowherb originates from New Zeeland and bears a strong resemblance to the now ubiquitous invasive E. brunnescens. E. pedunculare differs from Ebrunnescens in having toothed margins to the leaves and is naturalised here and there in the UK hills.

Epilobium pedunculare,
The Rockery, RHS Wisely, April 2013

Moving rapidly on to Kew. One plant I noticed spreading profusely in the temperate house was the Yellow-flowered Strawberry, Potentilla indica. This species with its distinctive large green epicalyx is naturalised in a few places in the UK. Since returning from my trip I noticed a large patch of this species growing by a path I frequently walk in Aberystwyth.  

Potentilla indica, Temperate House, RBG Kew, April 2013 

A species that was rampant in a couple of the Edinburgh glasshouses was labbled Nertera balfouriana but according to the on-line Flora of New Zeeland is actually N. depressa. A name that is, in turn, a synonym of Nertera granadensis. This small creeping plant of the family Rubiaceae is a native of damp places scattered across the Southern Hemisphere. Vegetatively it is reminiscent of a small species of Stellaria though the multitude of small purple spots on the stems help make it distinctive. More robust forms of Ngranadensis are grown as house plants for their impressive show of orange berries and it has been recorded as a garden escape in the UK.    

Nertera granadensis , RBG Edinburgh, May 2013 

Oxford, G. (2011). Death of an urban myth-parthenogenesis in Uloborus plumipes. Newsletter-British Arachnological Society, (121), 6-8.

Wilson, R. (2011). Some Tropical Spiders Recorded in Leeds, West Yorkshire and a Review of Non-Native Taxa Recorded in the UK. Newsletter-British Arachnological Society, (120), 1-5.

Saturday, 18 May 2013

Eden Project

I recently returned from the second stage of botanical garden tour. The garden I visited is one unlike any other, The Eden Project. More a grand socio-architectural statement than a collection of plants Eden is without doubt very impressive even if the plants don't always take centre stage.

The Mediterranean Biome at Eden, April 2013 

From the lip of a disused china clay pit a steep track makes a zigzag descent to Eden. At the top of the slope I was distracted from my introductory wander by a stand of large rugose-leafed plants. These were Balm-leaved Figwort, Scrophularia scorodonia. This species has a very limited distribution in the UK, being confined to the south-west and I can not recollect having encountered it previously. However since my return I happened upon this species in my home town of Aberystwyth where it has escaped from the garden of the late Ceredigion botanist J. H. Salter (Chater, 2010).

Scrophularia scorodonia,
Eden Project, April 2013

Following my informative tour (with Tim Pettitt) I began surveying in the Mediterranean Biome. A couple of hours of crawling through the prickly arid scrub yielded a number of surprised looks and a wide range of weed species. These included the ubiquitous, the unidentified and the probable intentional introductions. One species in this latter category was Tall Rocket, Sisymbrium altissimum. A frequent weed in most of urban Britain it still presented a slight puzzle for a occidental botanist such as myself.        

Sisymbrium altissimum, Mediterranean Biome,
Eden Project, April 2013

Moving then to the Tropical Biome, a confusing situation for any attempt at the eternally complex question of defining 'what is a weed'. Many ground cover species had clearly been introduced for the express purpose of going 'wild' so, while they were self propagating, this was their intended purpose and, therefore, not a 'weedy' characteristic. Anyway, the most virulent coloniser was a species of a family with which I was not previously familiar; the Acanthaceae. This tropical family is well represented in UK tropical houses and seems very geared toward vegetative colonisation. The identity suggested for this by someone (I can't remember or find his name) at Eden was a species of the genus Nelsonia.              

Probable Nelsonia sp.
Tropical Biome, Eden Project, 
April 2013

The Tropical Biome was also full of insect life. Particularly noticeable was the White-footed Ant, Technomyrmex albipes. This tropical tramp species, originally from the Indo-Australian region, has recently colonised western glasshouses and has rapidly become a significant pest at the expense of other tropical ant species. In at least one case it was purposely introduced to control another ant species. At this task it  excelled, but, as evidenced by many such examples, the biological control agent replaced  the problem rather than eradicating the problem (Boer, et al., 2008).  

Probable Technomyrmex albipes on a Strelitzia flower ,
Tropical Biome , Eden Project, April 2013

Leaving the Biomes I noticed a tiny red splash of colour among the gravel. This was the Mossy Stonecrop, Crassula tillaea. This species has a rather scattered distribution and seems to be spreading. Of the three records for North Wales shown on the BSBI map I know two of the sites are car parks at popular tourist destinations. I presume that it is being spread on car tires from one car park to the next on the wheels of unsuspecting holidaymakers.     

Crassula tillaea, Eden Project, April 2013

Wandering out through a wooded area I came across a planted glade of primroses and cowslips as well as two plants of their hybrid Primula x polyantha. This hybrid is frequent almost whenever the parents meet and probably arose in situ. This is also the parentage of a number of the showy horticultural Primula varieties.

Primula x polyantha,
Eden Project, April 2013

Boer, Peter, and Bert Vierbergen. "Exotic ants in the Netherlands (Hymenoptera: Formicidae)." Entomologische Berichten 68.2 (2008): 29.
Chater, A.O., 2010, Flora of Cardiganshire. Self published, Aberystwyth.