One Man's Friend is Another Man's Enemy.

 ONE MAN'S FRIEND IS ANOTHER MAN'S ENEMY (INVASIVES 1)

 Jack-by-the-Hedge or Garlic Mustard is a common wayside plant. It’s leafy stem comes up as a cluster of small four-petalled white flowers in April and May.  Alliaria petiolata, its scientific name refers to its garlic flavour, from Allium, the Onion genus. It is native in the British Isles, and throughout  Europe and  also occurs  in much of Asia.

 

Garlic Mustard leaf clump before flowering.

Flowering stems. Jack-by-the- Hedge belongs to the cabbage and cress family. It has four small white petals. Other names include Sauce Alone, Poor Man’s Mustard, Penny Hedge, and Hedge Garlic. The number of old names indicate its usefulness as a culinary plant in days gone by.

 

The leaves, eaten while tender and young are a good addition to a mixed salad, tasting mildly garlicky, but they get tough and stringy when older. It’s also a favourite food plant of the Orange Tip caterpillar.

 

Usually only a single orange egg is laid on each plant as the caterpillar is a carnivore and will eat any would-be companion.

 

It seeds prolifically. I found I made a mistake by adding it to my salad bed in the garden as it now comes up everywhere. Though easily pulled up as a seedling, if you leave it (as I tend to because of the Orange Tips) you find you have a persistent perennial with deep fang-like roots.

A few years ago I was sent a newspaper cutting from the local paper in Des Moines, Iowa, telling of a group called The Friends of the Park who were conducting a campaign to try and eradicate their foe, Garlic Mustard (no rather endearing nick-name for them!). The plant had somehow been introduced there and was now running amok.

Purple Loosestrife (Lythrum salicifolia) The attractive riverside summer flower in the UK is also supplied by  plant nurseries in several cultivated colour forms. It is  an invasive alien in the United States, where it forms a dense growth along shores and streams, preventing access to the water and overwhelming the native flora. Native to Europe and Asia, it was introduced to North America in the 19^thcentury.

               Purple Loosestrife it is a robust perennial growing to a metre or more when in flower.

                It has square stems. The willow-shaped leaves give it the scientific name salicifolia.

 

Mind Your Own Business, (Soleirolia soleirolii). Such a delicate, innocent-looking plant with tiny neat little leaves is sold by plant nurseries as a little cushion pot plant.

 

It has been given all sorts of gentle-sounding names like Friendship Plant; Baby Tears; Angel's Tears; Paddy's Wig.

 

 

Also known as Helxine, it was a Victorian favourite, often grown as an edging plant.

  But BEWARE!! It loves damp shady conditions, but break off a tiny fragment of stem and it will root, and in no time it will produce a dense mat of bright green, creeping among your plants, smothering the less robust, and is virtually impossible to eradicate . Attempts to remove it just breaks bits off which will start all over again. I speak from bitter experience. It was already growing in the garden when we came here over fifty years ago but the colder winters which happened more often back then at least checked it. Sharp frosts will reduce it to a tight mass of blackened roots which slows down its recovery in the spring. But gradually over the years, with fewer hard spells of weather, and a result of more cultivation  throughout the more or less derelict garden that we came to, it has popped up in many of our garden beds.

It is a native of Corsica and Sardinia and people who have been once-bitten, twice shy call it Corsican Curse! An unlikely-looking member of the nettle family, it is said to have minute pink flowers, but I must confess I’m too busy rooting it out to have stopped to look for them. I don’t use weed killers, but anyway, it’s said to be resistant to them.

Winter Heliotrope (Petasites fragrans) Another Victorian favourite, with, as its name suggests, fragrant flowers, led me to introduce this thug into my garden. I paid the price for my gardener’s acquisitional greed because it took me a good ten years to get rid of it again! It spreads with thick deep white roots, and garden chuck outs result in many hundreds of yards of roadside populations of a complete monoculture of the thing.

A dense stand of Petasites.

There must be something good to be said about it? Its flowers, a rather dirty pink, and  vanilla scented, appear in the middle of winter as the leaves are beginning to grow again, and no doubt produce nectar for early insects. It was sold to the unwary as a ground cover plant but the downside of ground cover is in this case, total smotherer!

It was introduced in the eighteen hundreds from Southern Europe where it is native. It is a member of the Daisy family and closely related to our native Coltfoot but its leaves are bright green, rounded in shape and without the white felty underside of Coltsfoot.

 These plants, and many others so often introduced with the best of intentions, exemplify the Law of Unintended Consequences! 

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What's in a Word?

 What's in a Word?

The English language is infinitely rich, containing words derived from many other countries in the course of our history, and new ones are being added all the time. I was saddened to see calls on the social media recently, to simplify our spelling, bringing it into line with the argot used on smart phones and text messages. At a stroke, our language would be over-simplified and infantilized, and the subtleties lost. I hope this idea doesn’t catch on.

Consider the slightly different meanings of ‘different’, ‘variety’, ‘variability’......

This train of thought was triggered the other day when looking at a planting of Beech trees by the Duchy College in nearby Stoke Climsland.  About 30 years ago a row of Beech saplings was put in. The young trees were all more or less the same age and growing in the same area under the same conditions apparently. Now established trees, it was noticeable that almost all of the 187 I counted were still looking wintry, with leaf buds still tight. But two or three were just beginning to unfurl and five or six were in full young leaf. In this case ‘different’ would infer some of them had a ‘different’ behaviour but they were all the same species of tree. I think ‘variable’ fits the bill in this case too. I would reserve the word ‘variety’ unless I could establish that each tree’s behaviour was consistent in every year.      

 

One of a very small minority of the planting of Beech trees with unfurled leaves, well ahead of the others.

 The same day our attention was drawn to the brilliant amber young growth of Sycamore in a hedge of mixed species. Most of the Sycamores were still in tight bud, a few had opened with ‘normal’ green leaves. but an exception was the one in the picture below with brilliant rufous young leaves, although still the true wild Sycamore Acer platanus.Why do some individuals of some species show this colour in the young leaves? It is caused by anthocyanin, a red pigment which is thought to protect the young leaf from damage by  insects and/or too much sunlight . This pigment disappears when the plant is in full growth and the green chlorophyll prevails. But why only some of the Sycamores, and why not the Hazels or other species? And is this behaviour in this individual consistent every year? Is this ‘variety’ or ‘variability’? Only marking the plants and looking each year would tell me. 

 

 

The Sycamore with coloured leaves stood out in contrast.

 

I know that the same Hazel bush when I was a child in Hertfordshire could always be relied upon to produce ‘Lambs Tails’ several weeks earlier than any other hazel in the area. I think ‘variety’ or, in the botanical sense ‘form’ would be appropriate here. In this case defined as a noticeable morphological deviation which is consistent. For example Rosebay Willowherb  flowers are generally rosy-red, but there is a form which has white flowers, and botanists give this as ‘form alba’.

I have found that people anxious to learn to identify flowers can be thrown by the stated size of a plant in question in a plant book. They can take this too literally and be mis-directed in their quest because their specimen doesn’t agree with the printed information. Whereas in fact a plant can be extremely variable in size and habit according to the conditions it’s growing in. I remember a friend finding Thyme-leaved Speedwell. The book said 2 to 6” tall. My friend’s example was 8” tall because it was growing at the side of the path  in looser untrodden soil and probably a little more run-off so it was growing comparatively luxuriantly. But my pal insisted it was too big and must be something else!

Variability is a fact to be taken into account when identifying a species.

So there are many pitfalls for a learner which only more experience overcomes, and a wealth of unanswered questions within the natural world to keep everyone interested.

 

 

 

 

CORNISH RIVERS 1 : THE LYNHER IN SPRING

 THE LYNHER IN SPRING

Unlike the Tamar which runs from North to South, forming the boundary between Devon and Cornwall, most of Cornwall's rivers rise on Bodmin Moor and radiate from it in all directions in their short rush to the sea. 

The River Lynher rises on the north eastern side of the moor and in its 21 miles it runs from moorland, south -east through an ever-widening valley of small pastures and woodland and eventually forms a tidal creek which joins the Hamoaze, the main estuary of the River Tamar where it joins the sea beyond Plymouth Sound.

Map showing the course of the Lynher from its source on Bodmin Moor just north of the main trunk road  A30 into Cornwall, to to the complicated Tamar Estuary at Plymouth.

Near the source. We spent two days following and photographing the river from end to end  in mid-April '21. It is a cold late spring.This is close to the source, at Hendra, between Trewint of John Wesley fame, and Bolventor, immortalized in Daphne du Maurier's novel "Jamaica Inn."

 

Rising in a marshy depression the young river flows through wet 'willow carr', the trees draped with moss and lichen.

 

Running downstream

Clumps of Golden Saxifrage on the banks.

Although the moor was looking very sere and wintry still, we heard our first Willow Warbler singing its sweet clear cadence in these willows.

About a mile downstream the river is now running through small pastoral farms on the moor's edge. I was going to crop off these signs of abandoned rubbish but I couldn't resist making the point. Now especially, as all sorts of people are being blamed for the increasing tide of litter in the countryside but farmers never have the finger pointed at them for  their abandoned plastic containers and the ubiquitous black plastic wrap sheeting...... Undeterred, a Blackcap sang in the sunshine.

Ford crossing to another of the small farms. The land is cold, wet and heaven knows how these farms wrest a living from this unforgiving place. The next photo shows closer-up the little clapper bridge of great granite slabs.

The wet woodland here is mostly Alder carr. Each tree forms  at its foot, a higher little island of dryer ground where bluebells grow, and sometimes Early Purple Orchids.

Tony found old Otter spraint on this  squarish stone in the middle of the picture.It's distinctive musky but not unpleasant smell is surprisingly long-lasting.

Running south, now swollen by several other streams  the river skirts the eastern side of the moor in a widening valley.

The little lanes here are showing signs of spring now. as we come down off the moor.

Young fronds of Harts-tongue Fern are unfurling.

Sycamore leaves unfolding, delicate apricot at first.

Looking down at part of the pretty village of Berriowbridge from the first old  stone bridge over the river. Like all of these crossing places there was once a mill (which ran a saw) but only relics survive in buildings now derelict or converted to dwellings.

Looking downstream at Berriowbridge. On the left a fenced-off portion of the riverbank allows cattle to drink but not stray far into the water.

After over fifty years here, I had never spotted till now, the stone steps at the side of the bridge, leading down to a well. The villagers preferred this water to the mains supply till it became contaminated by development, I am told. They said  the well water tasted better.

Ivy-leaved Toadflax growing in the mortar of the bridge.

Downstream another couple of miles. The bridge at Bathpool. Tony has found Brown long-eared Bats roosting under the arches of this bridge in the past.

Brilliant male Grey Wagtail. These birds nest in the river banks and perch on river boulders, wagging their long tails.

As we go south the banks are swathed with Scurvy-grass. This isn't a grass but a member of the cress family, the leaves claimed to be rich in Vitamin C.

             Orange Tips are now quite widespread this spring.

 

 

 

 

 

 

 

 

 

 

  

Patches of Common Violet (not the perfumed Sweet Violet) growing on the lane banks with Greater Stitchwort and the first of the Bluebells.

Continuing downstream we come to Stara Bridge. The river has passed through an area of woodland, some of which is  a commercial coniferous planting, but managed as a Nature Reserve now.  Note the flood channel arch on the right. The Lynher is known as a 'spate river' which floods readily following significant rain in its upper catchment.

Carpets of Greater Woodrush grow in the wooded valley bottoms.

Wood Anemone.

Wood Sorrel.

Going over Stara Bridge. Note the triangular  refuge points for pedestrians to step into when traffic comes. The dark coniferous plantation is beyond and the flood channel arch can just be seen on the right.

These old, originally medieval bridges are these days having to be strengthened, and because they are narrow some of them are frequent victims of wide lorries.

Passing through a patchwork of valley bottom meadows and a tangle of woodland, the riverbank is maintained by various fishing clubs, restricting access in parts. The clear clean fast-flowing river with deep pools and shallow riffles is a favourite Salmon and Sea Trout water.

The handsome bridge at Rilla Mill. The mill here is gone too.It once powered a workshop for farm machinery.

Approaching the river again, at Bicton Mill, another converted mill.

But here we can see the remains of one of two water wheels .

I should imagine this is a fisherman's paradise in this tranquility.

Moschatel is a small, early-flowering plant growing in the shadier parts of the riverbank, quite a speciality of our Cornish river valleys. It disappears later in the season. The distinctive flower looks in five directions. Mum used to call it 'Town Hall Clock'.

One of the principal river crossings is at Callington New Bridge, on the main road from Tavistock through Gunnislake, Callington and on to Liskeard and Bodmin. It was originally a medieval turnpike and the toll cottage, rebuilt in the eighteen hundreds, has been derelict for several years but is now being restored extensively.

Situated at the bottom of the hill and with a sharp bend as soon as you cross, this bridge parapet is frequently knocked about by traffic misjudging the road! It's a good spot for Dipper watching, preferably from the bank below.

Just past the bend a narrow lane runs from the main road, straight up the hill. At the top is a granite marker stone saying 'Take Off' where an additional 'cock horse', hooked on at the bottom to help the coaches and carts to get up the steep hill , was unhitched again and returned to the stable down by the bridge.

Dipper.

Downstream an extensive area of old oak woodland is a very popular walking place, with a car park just below the New Bridge. There is an abundance of the invasive garden weed Variegated Yellow Archangel. Obviously the car park makes for easy  garden  chuck-outs!

A gingery Bumble Bee (The Common Carder Bee) is foraging for nectar.

Lady Fern unfolding. The delicate fronds are the first to die back in the autumn but conversely appear very early in the spring.

The wooded areas in the valley bottom are frequently  flooded and have seasonal pools  among the trees with flag iris and king cups.

The river downstream from Callington New Bridge runs along the base of a steep hill known as Cadsonbury. This is a National Trust holding with a large Iron Age hill fort on the top. This picture is looking east with Callington out of sight just to the east of the horizon. Looking down  from the bank of the earthwork, the area of dense woodland hides the river and the paths alongside it.

A mile or two further downstream is Pillaton Weir, with the sluice controlling a leat running to a mill further down the valley.

The main part of this once substantial weir is now broken down, presumably by repeated floods. Some forty or more years ago we watched salmon leaping the weir here.

Open rolling country with the river running through the valley south of Pillaton

Blackthorn is abundant in the hedges.

Looking downstream from the old Notter Bridge. The upper limit of the tidal water is here. The main A38 trunk road from Exeter to Penzance has been slightly re-routed and crosses the Lynher a little further away now on a modern substantial bridge.

These plaques are on the old Notter Bridge but I don't know what they represent.

Just below St Germans where the main tributary, the River Tiddy comes in from the left and joins the Lynher coming in under the railway viaduct. The river bends sharply to the east. This is about high water but extensive mud flats at low water attract wintering waders.

In the words of Dylan Thomas these were once 'heron-priested shores'

Since the 1980's Little Egrets have become frequent in our estuaries and now they seem to be commoner than Grey Herons, but perhaps that's just because they show up more and have a more active and visible feeding habit.

There is a good deal of arable farming here beside the estuary.

This pretty little Rue-leaved  Saxifrage is a bit of a SE Cornwall speciality. It flowers early in the spring then disappears. It grows on top of stone walls and other rubbly gravelly places.

There are only very small area of salt marsh in the estuary.

 

 

 

 

Near the end of the road, above Wearde Quay, looking towards the Hamoaze where the Lynher joins the main part of the Tamar estuary and it goes through Plymouth Sound to the sea.

The end of the road at Wearde Quay.

 In the space of two days, following the course of the river we also travelled from winter up on the moor at about 300 metres, to spring at almost sea-level at Wearde Quay.

Thanks to Jen & Pete Bousfield for information about some of the mills, and to Tony for chauffeuring and co-photographer. 

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