The South Hams

Unless you see it for yourself, it is hard to appreciate the level way the hill tops of the South Hams meet the Devon sky. Stopping my car between Malborough and Salcombe I see a flattish horizon lying around me: the hill tops mark the surface of a gently wavering plateau. Just a few gentle undulations here and there detract from the general impression of a broad concordance of summits in the countryside between Dartmoor and the coast.

You can only see this plateau landscape from high places; stand anywhere in between them and you will just see hills and valleys. Car drivers in the South Hams are forever climbing slopes or dipping into troughs - but summit views tell a wide and level story. In the same way, a trawler captain might rise to a wave top and see all crests forming a composite, flat horizon that belies the rising and falling of his little ship.

The high points include summits at East Prawle (443 m), Blackdown Rings at Loddiswell (580 m) and Stanborough Camp (700 m). Lying between them and the sea is a complex, rolling mass of lesser hills, slopes, valleys and coombes that form the physical heart of the South Hams. We should not forget the contribution made by the long, dendritic estuaries - the rias - that penetrate the land mass, where lower reaches of valleys such as the Erme and Dart have been drowned by the sea. These valleys continue inland and are fed by a welter of coombes scooped out of red-brown Devonian bedrock.

I have never understood the origins of this summit phenomenon. Old-time geographers talk about  peneplanation, suggesting that the landscape was planed off in the late Neogene period. My teenage mind's eye used to hold an image of an immense wave-cut platform uplifted and then dissected by rivers. That does not make sense. What about glaciation - have the summits been planed by ice sheets? There is no evidence that this landscape has suffered anything more than periglacial processes in the freezing hinterland beyond the southern limits of Pleistocene glaciation. The slopes and coombes are thickly bedded with frost-shattered debris, but not outwash gravels nor till - not even on Dartmoor. There remains the idea of subaerial erosion as the most plausible agent, set against a history of rising and falling land levels over millions of years.

The rocks underlying the South Hams are mostly of Lower Devonian age - mostly slates and mudstones, perhaps 410 million years old. You can see them everywhere in walls, or in rocky lanes.

Supposing the South Hams were an extremely ancient terrain, perhaps tens of millions of years old. Suppose an eroded landscape of Devonian rocks was once covered by the sea, buried in sediment and then uncovered - then perhaps buried again, then exhumed once more - and all the while the land levels and sea levels were rising and falling over immense stretches of time. The South Hams landscape may have been roofed and unroofed several times over, and what survives is a battered and extremely ancient relict terrain, now seen as a complex of flat summits, hills and coombes - over which farms and villages, woods and hedgerows have been laid out in the blink of an eye.

I cast my imagination 60 million years into the future. Like HG Wells' time traveller, I see the land and its wrinkled skin of green landscape blur and then dissolve.

What's left there is ocean. 

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Salcombe

Salcombe is a Devon sea town of white houses and grey roofs set on a rounded hillside. Sometimes a quite modest house with a good aspect can sell for a million, especially if it looks onto the harbour or estuary - that steep notch in the coast where tidal waters surge in and out of the South Hams through a drowned valley or ría, flanked on one side by the craggy rocks of Bolt and the lower cliffs of Portlemouth Down on the other. This is the window frame through which Salcombe views the outer world and mariners see the town. Climbing tiers of houses are interlaced with dark holm oaks and umbrella pines, giving the town a Mediterranean feel. Its spirit looks seaward and southward.

28-3-2016

My sister Pip and I went walking today in the sunny, breezy aftermath of a storm which had battered Devon with 70 mph winds and driving rain the night before. Salcombe has interesting routes for walkers to choose from: pretty, high-banked lanes that loop inland through woods and secluded coombes, or climb to bald summits with panoramic views; coastal paths that go tracking out round the estuary's gentle indentations or  threading boldly the harsh, sea-girt declivities of Bolt.

There are also paths in the town where the nature of Devon and far-off places are mingled in startling southern conjugations. Wooded slopes too steep for houses show a native flora of oak and hazel, pennywort and primrose enriched by all kinds of exotic garden escapes. The mild oceanic climate means that local gardeners can be adventurous with their choice of plants: one of the footpaths is overhung with a pineapple palm (Phoenix canariensis) from the Canary Islands. Southern species such as the holm oak (Quercus ilex) may last have been native here 10 million years ago in the Miocene, when subtropical forest covered Britain, including elements of the beautiful laurissilva now found in the Macaronesian group of islands off the African coast (e.g. Madeira, Tenerife, Cape Verde). They were later pushed south by advancing Pleistocene ice sheets, but have now returned - with human help.

My most joyous discovery has been the tree echium, Echium pininana, from the Canary Islands. As we followed a wooded path we came upon spectacular, long-stalked, bushy plants, rather like dark-green shaggy clubs. Dried woody remnants of last year's dead stalks towered alongside us, reaching well above head height.

Tree echium has an interesting story, recently deciphered by botanists using molecular genetics [1]. The genus Echium originated as a herbaceous plant living round the Mediterranean, then spread to the Macaronesian islands when they formed, one after the other, by volcanic action over the last 20 million years. As Darwin and other have noted, herbaceous plants on islands tend to evolve a woody growth habit, so a new range of woody Echium species evolved in Macaronesia, able to grow to a remarkable height. Echium pininana is one of them, an endemic of La Palma in the Canaries. Research shows that it arrived in the Pliocene epoch about 3.73 million years ago [2].

I have never visited the Canary Islands, but I have been captivated by photos of their enchanting forests, volcanic mountains and luminous atmosphere. They are on my life's list of places to visit. I would not be put off by the thronging coastal holiday resorts; they'd just be a cheap place to roost in between day excursions to explore the vegetated, rocky interior. If I were on La Palma I'd make a point of seeking out Echium pininana. It is not too late for me to do it.

Tree echium is a monocarpic plant. That means it flowers once then dies. It lays down wood then builds itself up over two or three years before spending itself in one final, magnificent, spire-shaped spasm of mauvy-blue flowers. I may never make it to the Canaries, but I'll be happy to visit Salcombe again one July or August to catch Echium pininana at its moment of Macaronesian glory. The plants I saw this week look as though they are preparing themselves for a mighty show.

Echium pininana photographed on Guernsey.
Image courtesy La Société Guernesiaise.

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References


1 - Bohle, U-R et al (1996): Island colonization and evolution of the insular woody habit in Echium L. (Boraginaceae); Proc. Natl. Acad. Sci. USA, Vol.93, pp.11740-11745/.
Online at: http://www.pnas.org/content/93/21/11740.full.pdf [April 2016]

2 - Kim, S-C et al (2008): Timing and Tempo of Early and Successive Adaptive Radiations in Macaronesia; PLoS ONE. 2008; 3(5): e2139.
Online at: http://europepmc.org/articles/PMC2367450#pone.0002139-FranciscoOrtega2/. [April 2016]

Rock Samphire

2nd August 2014

A warm, boisterous wind is pushing me around today on Bigbury beach, south Devon. I am here with family enjoying the wide expanse of sand and sparkling sea. Rough, slaty cliffs make a backdrop to the beach, and their rocky outcrops provide a choice of sheltered places for setting out a picnic.

The rocks and pebbles are a galaxy of subtle pinks, greens and grey slates of Lower Devonian age, classified by geologists as belonging to the Meadfoot Beds. They have been polished smooth in the zone below the tideline, but remain sharp and pitted by salt spray weathering above it. The bedding of the rock is almost vertical, being evidence of severe folding after it was deposited. Up in the cliff, the bedding has been further distorted in places by frost action during the Ice Age, shattering and remobilising it into interesting patterns.

The sea is working a further transformation on the slates, steadily recycling them into pink, green and grey sand. This will, in turn, feed the formation of other rocks - on multi million-year timescales.

Up on the cliff, tiny roots are also doing their part in breaking up the slate. Pale green patches of Rock Samphire (Crithmum maritimum) are growing in any places where their roots can penetrate. They have sought out joint planes in the rock, where rainwater is concentrated and a rudimentary soil has formed. The result is a pattern of hanging gardens scaling the rock face, with neat rows planted by nature.

Rock Samphire gives me a pang of nostalgia for southern skies. It looks as though it belongs - as it essentially does - to the Mediterranean world; it is found along warm coasts from the Black Sea to Atlantic Europe. It has a pleasant, aniseedy smell which reminds me of fennel and the holiday aroma of ouzo and pastis; they call it 'sea fennel' in Latin countries [1]. Its fleshy, drought-resistant leaves look good to eat, but reportedly taste like 'a mixture of celery and kerosene' [2]. I suspect this may be an effect of the phenolic and tannic phytochemicals it contains [3].

Rock Samphire has evolved to exploit this rocky niche; I can't see any other plants competing to occupy this bit of uncomfortable, salt-blasted, sun-baked habitat. It is triumphantly doing what it is best at. 

Every plant expresses the special will of its species, and says something that cannot be expressed in any other language. [4]

Schopenhauer's thought leads me to new insights. Living things may be seen as verbal forms as well as nouns. They are dynamic doers and effectors. Crithmum maritimum does what it does - says what it says - according to the deployment of its genetic programming. It 'crithmums' at the genus level, and 'maritimums' at the species level. We can see it as a kind of selfhood - deploying life-seeking information specific to its own kind, existing and acting in the service of maintaining and reproducing itself. If Rock Samphire tastes like ‘celery and kerosene’ that is because it needs phytochemicals to defend itself from being eaten where it stands.

Here, I find Crithmum maritimum growing in rocky clefts. As a species, it is bound to its particular ecological niche, and as individuals these plants are bound to their clefts. They are constrained to make the best of their circumstances, and as individual plants fixed to the soil in which they are rooted (for better or worse) they can only transcend them through effective reproduction strategies. I reckon plants are absolute, blind optimists: they must wait for their environment to bring them what they need. By contrast, animals can move around and seek better circumstances, mate with whomsoever they will, but as a consequence they are naturally prey to the ceaseless, questing dissatisfaction which Schopenhauer identifies as their existential condition of all living things, and which the most conscious beings experience most acutely [5]. Psychologically, I reckon the more conscious an animal is the more capacity it has for pessimism as well as pleasure. Animals in zoos may mope or go mad [6].  

I am an example of the most mentally complex species present on Bigbury beach today - a human being. As an animal, I can exercise existential freedoms that are denied to Rock Samphire. I am able to make choices about where to lay my towel down on the beach or what food to eat. Like a dog I can choose where to dig a hole in the sand, or like a herring gull I can think how best to tackle a picnic hamper.

The onshore breeze is strengthening as the afternoon wears on. As an animal I am free to decide many things for myself - I can change my circumstances.

I think it's time to put on a pullover and fetch an ice cream from a café a few hundred yards away.

My innate pessimism tells me the café is sure to be closed by the time I get there.

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References

[1] - Crithmum maritimum L. Gardening in mediterranean climates worldwide. Online at: http://www.gimcw.org/plants/Crithmum.maritimum.cfm [accessed August 2014]
[2] - Crithmum maritimum L. Plants for a Future. Online at: http://www.pfaf.org/user/Plant.aspx?LatinName=Crithmum+maritimum [accessed August 2014]
[3] - Houta, O, Akrout A & Amri, H (2011): Phenolic amounts, antioxidant and antimicrobial potential of Crithmum maritimum cultivated in Tunisian arid zones; Planta Medica 77. Online at: https://www.thieme-connect.com/products/ejournals/abstract/10.1055/s-0031-1282826 [accessed August 2014]
[4] - Schopenhauer, A (1969): The World as Will & Representation; Book 1, chap.28. Dover Books. 
[5] - Schopenhauer, ibid; chap.56.
[6] - Masson, G  (1996): When Elephants Weep: The emotional lives of animals; Vintage Books.

Enchanter's Nightshade

With such a compelling name, Enchanter's Nightshade must surely have magical powers. Its Latin name Circaea lutetiana was given to us by Carl Linnaeus, that intrepid genius of the imaginative epithet. 'Circaea' comes from Circe, a powerful enchantress in the Odyssey, and 'lutetiana' presumably from the ancient Gallic town of Lutetia, which is now Paris.

A plant of shady places, the white flowers of Circaea lutetiana shine like tiny candles in the gloom of woods and hedges. The contrast between its large, robust-looking leaves and its spindly, fragile-seeming stalks fitted spaciously with small, luminous flowers is remarkable. Its large leaves seem equipped to harvest as much of the scanty daylight as they possible; its flowers seem devoted to the art of luring micromoths. Linnaeus, who had an eye for the mythic and erotic dimensions of the plant world, has cast the plant is the role of an attractive Parisian enchantress - all libido and lace.

Enchanter's Nightshade and Cuckoo-Pint

The plant has been slipping in and out of my thoughts for the last few days - not entirely sure why. Perhaps it is because I found some Black Nightshade (Solanum nigrum) recently in Norfolk, and have been meditating on its name. Perhaps it is fallout from a relationship with a certain lady in which I feel powerless to move in any direction that satisfies my heart. The painting of Merlin and Nimue by Burne-Jones comes to mind - the enchanter finds himself enchanted. 

I came across Circaea lutetiana yesterday in a Devon hedgebank - a high bank sheltered by trees with a magnificent view over hilly South Hams countryside between Harberton and Totnes. It was keeping company with Arum maculatum, otherwise known as Lords-and-Ladies or Cuckoo-Pint. The one a spindly complex of dull green and flickering whiteness; the other a stalk topped by lurid orange knobs. The two could hardly be more different.

I am not sure what sorcery Enchanter's Nightshade can work. Perhaps it has the power to manage painful separations.

      Yes, thou art gone! and round me too the night

      In ever-nearing circle weaves her shade.

                                          [Matthew Arnold, 'Thyrsis']

Perhaps it is just a light in dark places.

Meanwhile, cloud shadows move over the Devon landscape, and life moves on.