Tuesday, 30 December 2014

Lichens and leaves.

The lichen Psilolechia lucida. Christchurch
Road, Daventry. 28 December, 2014

One of Britain's commonest lichens is Psilolechia lucida. It forms extensive pale green patches on suitable stonework. Tom Chester has said it is 'almost as if a child with a large green stick of chalk has been on the rampage'. (British Wildlife, Vol. 8, pt. 33, p.166) But, common though it is, it is very exacting in its needs, requiring the correct levels of moisture, light, and stony substrate. This brick wall in Daventry's Christchurch Road seems to suit it. Lichens are regarded as primitive organisms, with an intellectual level only slightly above that of the Sultan of Brunei*.

30 December, 2014

Last night was bitterly cold (and even by noon the temperature had only managed to achieve 6 degrees). A sharp frost had left roads and footpaths treacherous but I girded up my loins and set off for the local pocket park. Several wolves were bounding around, fortunately in the domesticated form, accompanied by their owners. Genetic research suggests that our dogs are descended from the single domestication, some 15,000 years ago, of a wolf-like canid which is now extinct, but the picture is very complex, with much more research needed.

Frozen leaves, in a considerable variety, crunched beneath my feet.

The commonest were those of the Sycamore, Acer pseudoplatanus. This is probably an introduced tree in Britain but, as with dogs, the picture is not yet clear and a reasonable case can be made for this being a native to this country. Hybrid Acers are frequent and this leaf shows some of the characteristics of the Norway Maple, Acer platanoides.

Leaf of Field Maple, Acer campestre, at Stefan Leys
Pocket Park, Daventry. 30 December, 2014

The similar Field Maple, Acer campestre, is undoubtedly native to Britain and can be recognised by the rounded lobes of the leaf edge.

Leaf of Sessile oak at Stefan Leys Pocket Park,
Daventry. 30 December, 2014
We all know the oak of course but very few are present in Stefan Leys Pocket Park. The leaf shown is that of the Sessile Oak, Quercus petraea. This species is native to Northants though much less common than the Pedunculate Oak, Quercus robur. Here the Sessile Oak is undoubtedly planted.

Leaf of Small-leaved Lime, Tilia cordata. Stefan Leys
Pocket Park, Daventry. 30 December, 2014

The leaves of Lime trees are distinctive for being abruptly narrowed to a tapering tip. This example appears to be from a Small-leaved Lime, Tilia cordata, again a native of our county but in this instance almost certainly planted.

Leaves of Beech, Fagus sylvatica, are simple in shape
and yet quite distinct. Stefan Leys Pocket Park,
Daventry. 30 December, 2014
Beech, Fagus sylvatica, though common and familiar to us all, is not a Northamptonshire native. It will - and does - regenerate from seed, but is initially always a result of planting. Among the loveliest of our trees, Beech is native in southern England. Its leaves are rather tough and are among the last to fall of our deciduous trees. They tend to be relatively slow to decompose.

Cherry leaves were abundant on the ground but I searched in vain for those of Alder, even though I carefully searched directly beneath a clump of the trees. Very odd!

*The Sultan, in his infinite wisdom, has authorised the introduction of sharia law, thus permitting the stoning to death of homosexuals. How civilised!

Saturday, 27 December 2014

Catkins at Christmas

It's not that I'm afraid of Santa Claus - I'm not claustrophobic - but one can have a bit too much of the celebrations. So, following an excellent Christmas dinner with my daughter Jacqui and her husband Dean, a walk around Daventry Country Park seemed like a good idea. Chris, Jacqui, Dean and yours truly set off in fading afternoon light to do a circuit, which basically means a circumnavigation of the lake/reservoir which forms the centre of the park.

Some fine trees are dotted around the park, with huge oaks and beeches, surely pre-dating the reservoir by many years, being particularly impressive.

This specimen, though not large, has the typical shape of an oak. The branches do not sweep elegantly upward or outwards but spread with oddly angled branches, these angles once being particularly valuable for shipbuilding and other construction work. We have two species native to Britain: in the south,the east and much of the midlands the Pedunculate Oak, Quercus robur is the most commonly met, but in the north of England, together with Scotland and Wales, the Sessile Oak, Quercus petraea, is the commoner, preferring the siliceous soils with their more acid reaction. The leaves allow identification but hybrids are frequent and I didn't attempt to put a name to this specimen.

The alga Trentepohlia abietina - probably -
staining the trunk of an Acer at Daventry
Country Park. 25 December, 2014

We pressed on in fading light. Tree trunks here and there were stained bright orange-red with an alga. It is a species of Trentepohlia, almost certainly T. abietina. It likes cool, damp conditions so is most frequent in the north and west of the British Isles. Here, close to a significant body of water, it is flourishing. There are very few records of this species on the NBN Gateway site, probably because people fail to notice it or aren't sure what it it they're looking at.

Catkins of Hazel in flower on Christmas Day!
Daventry Country Park. 25 December, 2014

I was on the point of putting away my camera when I had a surprise. Hazel catkins had no right to be in this state - releasing their pollen on Christmas Day. A bit of a waste of time really because there are unlikely to be any female flowers ready to receive the pollen. But it was a nice little bonus to round off the walk!

Monday, 22 December 2014

The Shortest Day - amended

Winter solstice, the shortest day of the year in the Northern Hemisphere, is 21 December. Of course, the soil and the environment generally will get chillier for a few more weeks before the extra sunshine begins to take effect.

For me, I'd rather be in the countryside but there's no doubt that being in a large town has its compensations.

Bergenia cordifolia in a flower bed, Leamington Spa.
19 December, 2014 (Note the carefully positioned
 camera strap, included to enhance the picture).
Municipal flower-beds remain colourful with carefully chosen plants. Bergenia cordifolia is a member of the Saxifrage Family and is planted for its early flowers (I can think of no other reason why people would plant this coarse species). Named after the German botanist, van Bergen, Its flowers are attractive enough but, oh those leaves; no wonder one popular name for the plant is Elephants' Ears. 
Cultivated forms of Bellis perennis share the same
Leamington flower bed.

Our common lawn daisy is Bellis perennis. Carefully selected strains provide large, brilliantly coloured flowers in the middle of winter. Do I like them? Yes - but I'm not sure why. The disc-flowers are always yellow but the rayed flowers around the edge can be bright carmine-red, as shown in the picture.

Sometimes the disc-flowers are almost non-existent and in this condition are known as flora pleno. This term is usually taken to mean 'double flowered'  but strictly speaking it just means 'full-flowered'.

Of course, it is not unreasonable to expect these bedding daisies to be in flower, because here, in a lawn, is its wild counterpart happily flowering in the teeth of a cold near-gale a couple of days later.

Chrysanthemum leucanthemum, the Ox-eye
daisy,  blooming despite a cold, buffeting
wind. Browns Road, Daventry.
22 December, 2014

But what one does not expect is that its close relative, Ox-eye Daisy, Chrysanthemun leucanthemum, should be in flower on the same day. Yet here it is, in Brown's Road, Daventry; a bit tatty, yes, but blooming freely three months after flowering should have ceased!

Around Daventry, as in parks and gardens the length of Britain, Dogwoods are planted. I'm no great fan of these shrubs but the slender red or yellow twigs do create quite a pleasing effect, particularly when planted en masse.
Dogwoods, Cornus sericea, butchered by contractors.
Daventry, 22 December, 2014

The usual choice is Cornus sericea. Its upright twigs are a dark wine-red and, as I say, can be quite pleasing. It is therefore particularly silly when a local authority arranged for all the shrubs to be cut back hard, rendering their original planting quite pointless by removing all of their gracefulness.

The shape of certain plants is their most important main feature (and in the case of dogwoods, with their undistinguished, off-white flowers, their only redeeming feature). I am pleased to note that more and more use is being made of hornbeams, Carpinus betulus.

It has to be said that these examples, with their up-swept branches, are rather different from the famous gnarled specimens growing in parts of the old Epping Forest. The trees shown are cultivars and have been selected for their shape. I had a rant recently about the mania among local authorities for Lime trees; these hornbeams surely make a much better choice and I am pleased to see that their usage is becoming widespread, with a lovely avenue of them beside the Oxford Road, leading out of Banbury.

A Lombardy Poplar at the edge of the
playing fields in Byfield, Northants.
23 December, 2014

This upsweeping form, known as fastigiate, is well-known from the more familiar Lombardy Poplars (Populus nigra, var 'Italica') where the shape is even more exaggerated. I am glad to say that this shape does not discourage the insects which depend upon these trees, for both Populus nigra and Carpinus betulus are native to Britain.

Eucalyptus gunnii tumbles over a fence in Daventry.
23 December, 2014

On the subject of trees, I was delighted - though not surprised - to find a Eucalyptus tree in full flower here in Daventry. The species in question is Eucalyptus gunnii and generally flowers about now. It is a native of Tasmania so, having been transferred to the northern hemisphere, it is to be expected that its flowering times are a bit out of synch.

Members of the genus Eucalyptus are mostly (all?) from what was once called Australasia, so it may come as a surprise to find that they are members of the Myrtaceae Family and are therefore related to the European Myrtle, Myrtus communis.

So, in these short, gloomy days, there are things to be seen and mulled over. There has been much talk over the last couple of decades about S.A.D. (Seasonal Affective Disorder) but I suspect that a brisk walk in the local park will do much to dispel the feeling of gloom which descends upon many in these months. Well, it works for me.

On 23 December these Eucalyptus gunnii flowers
are hardly likely to attract insects!

Wednesday, 17 December 2014

On an old church wall

There are close on 1900 lichen species known from the UK. Most people are aware that a lichen is formed by a union of a fungus and an alga; the scientific name of a lichen is actually that of the fungal element. Let me emphasise that I am not a lichenologist - nor will I ever develop much expertise in this field. Nevertheless, when I see a tree trunk or stone surface encrusted with these extraordinary organisms I cannot resist having a closer look. 

Such was the situation when I strolled through the churchyard of Byfield's Holy Cross Church recently.

Verrucaria virescens (probably) on the church wall.
Byfield, Northants. 17 December, 2014

Who among us has not been stopped in our tracks by, for example, the tar-like patches of Black Pit Lichen, Verrucaria nigrescens, on a stone surface? Well, ok, I won't pursue that point. But to look at these organisms, clinging to a rock, it almost beggars belief that these are living creatures.

Cladonia chlorophaea on the church wall at
Byfield, Northants. 17  December, 2014

Quite different is the Mealy Pixie-cup Lichen, Cladonia chlorophaea. It doesn't occur on bare stone but grows where a layer of humus has developed. In reality this 'species' is an aggregate of very similar species - certainly not separable by the likes of me.

Acutely aware of my status as a tyro in the world of lichenology I moved on to look at the mosses and liverworts. But sadly my knowledge of these organisms, collectively known as bryophytes, is equally limited. But now and again I like to have a bash at identifying them.

Porella platyphylla on the churchyard wall, Byfield,
Northants.  17 December, 2014

Liverworts are widespread in Britain but I rarely notice them. However, I could scarcely fail to see the glistening curtain of Wall Scalewort, Porella platyphylla, as it clung to the churchyard wall. It requires a shady spot and if it is damp, so much the better - and these are the conditions in which I found it flourishing.

Orthotrichum anomalum clings to the churchyard wall
in Byfield, Northants. 17 December, 2014

Neat cushions of Anomalous Bristle-moss, Orthotrichum anomalum, clung to a drier part of the wall. Very widespread it is unusual among our Orthotrichum species; they are generally found on trees but this species much prefers stonework.

During these winter months one tends to pay more attention to mosses, liverworts and lichens. When I do so I never fail to be fascinated by their habitat requirements, their form and, yes, their beauty. If only there were about forty hours to each day, I might begin to give them the attention they deserve.

Monday, 15 December 2014

Of mushrooms and mosses

I am often asked what is the difference between mushrooms and toadstools. The fact is, there is no simple answer. The word 'mushroom' is generally reserved for edible fungi and, as I have mentioned before, 'toadstool' may come from the German words tod - death, and stuhl stool. However, it is probably just a fanciful name - a stool for toads to sit upon. But interestingly, toads were always regarded as poisonous in the Middle Ages and a rather nasty, mildly toxic, fluid oozes from the warts on a toad's back if it is roughly handled.

Prithee, Tony, what led you down this train of thought?

Strolling through Stefen Leys Pocket Park earlier today I chanced upon a couple of common but interesting fungus specimens. Both were edible, but many people wouldn't apply the word 'mushroom' to them. 

Shaggy Parasol, Macrolepiota rhacodes, var hortensis
Stefen Leys Pocket Park, Daventry. 15 December, 2014
The first was the Shaggy Parasol, Macrolepiota rhacodes. The variety photographed is var. hortensis. This is edible and tasty although some people have reported a mild gastric upset after a plate of them. Here it was, late in the year, beneath trees in the pocket park, surrounded by the bright green leaves of Herb Robert.

Although this species is easily identifiable from the patchy appearance of the cap, it is generally a good idea to look underneath to check the form and colour of the gills. These were as anticipated and the smell of the whole fungus was mild and mushroomy.
Pleurotus ostreatus, Oyster Mushroom. Stefen Leys
Pocket Park, Daventry  15 December, 2014

The Oyster Mushroom, Pleurotus ostreatusis common and also edible. Yes, it is called a mushroom, but its cap does not have the disc shape of the Common Mushroom; as it generally grows from the trunk of a tree this is understandable. The group I found were in an ideal condition for gathering and eating but, as they were at the base of a tree adjacent to a footpath, I refrained. Something about dogs...

I was able to get a decent photograph of the gills.

This late in the season I might, in ancient or even reasonably mature woodland, have found other fungi, but beyond the two species photographed I noted only a few more specimens, shriveled or nibbled beyond recognition. However, that is not to say that evidence of their presence was lacking.

At the edge of the site, hard by a garden fence, stood a cherry tree. It was in a bad way, the condition of the lower trunk showing that its days were numbered. The damage demonstrated a classic case of attack by Honey Fungus, Armillaria mellea. It is sometimes called the Boot-lace Fungus and I know that, had I probed the ground nearby I would have found the hyphae (vaguely equivalent to roots in a real plant) like black bootlaces snaking through the soil.

Although the trees were now devoid of leaves a Jay, screaming in the tree-tops, defeated my search for it. This handsome member of the Crow Family is far more often heard than seen.

That left mosses. The bryophyte flora was very limited and, although a hands and knees posture with a Sherlock Holmes-type magnifying glass would probably have paid dividends, I held my enthusiasm in check and contented myself with very obvious species.

Tortula muralis at Stefen Leys Pocket Park,
Daventry. 15 December. 2014

The Wall Screw-moss, Tortula muralis, is abundant in rural areas on stonework, walls and neglected footpaths everywhere. I found it at the edge of a concrete path. Mundane, yes; unattractive, no. There are certainly more striking mosses but a careful examination of its features will reveal the delicate form of the leaves with a rather long hair-point at the tip. It beats watching 'Strictly...' [Everything beats watching 'Strictly...' Ed.]

This next moss is, I believe, Kindbergia praelonga.  Known as Common Feather-moss it is indeed extremely common but I was rather fortunate in finding a patch with abundant capsules, for these fruiting structures are not often seen.

Kindbergia praelonga from Stefen Leys Pocket Park,
Daventry. 15 December, 2014

I brought a sample home and was able to obtain a marginally better photograph which tends to confirm my original identification.

There were a few other mosses about but I know my limitations. Perhaps I'll have another look at them sometime. Anyway, it was a dull day in mid-December; not the most auspicious of times to be out in a patch of urban parkland, so I was content with my findings. As Del Boy would have said, "Multum in parvo my son" - and in a way it was

Saturday, 13 December 2014

Ivy: strictly for hederophiles

We take Ivy for granted. I don't need to point out that it is extremely common and it regularly gets an honourable mention on my blogs.

So is there anything more to be said?

Ivy is a member of the Araliaceae, a moderately large family of trees, shrubs and herbaceous plants, together with a number of lianas - those rope-like climbers so often featured in films about rain forests. Altogether the family contains about 254 species. I say about, because the situation is confused and modern techniques of DNA analysis seem certain to lead to a number of changes. Examples of the family are found in all the continents - obviously excluding Antarctica.

Ivy, Hedera helix, is found right across the British Isles and the European mainland, avoiding only high mountains and waterlogged or very acid soils. It takes on many forms in some parts of its range and it is this variability which prompted me to write this blog.

Ivy. Typical leaves on a non-flowering shoot.
Daventry. 13 December, 2014

The typical leaf-shape of ivy is very familiar to us all, being palmate with 3 to 5 lobes. The veins are pale and stand out distinctly against the dark green of the rest of the leaf. When these branches come into contact with a suitable surface they will produce roots allowing them to cling to walls, tree trunks and so on. However, these branches never produce flowers.

Ivy. Smooth, cordate leaves on a flowering
branch. Daventry. 13 December, 2014

The leaves on flowering branches are smooth and more or less ovate with a pointed tip although, as in the example shown, they can be cordate, i.e. heart-shaped. These flowering branches do not produce roots.

Contrary to popular belief ivy is not a parasite; it is a nuisance but will not harm a strong-growing tree. Nor will it harm a wall if it is structurally sound.

Hedera helix in the form dubbed 'Clotted Cream'
Daventry, Northants. 13 December, 2014

Some curious variations are to be found.  This form with crinkle-edged leaves was sprawling over the wall of a car park in Daventry. It appears to be Hedera helix 'Clotted Cream'.

Ivy on the church wall at Norton, Northants.
13 December, 2014

But even the common ivy can take one some attractive forms. Claret-hued leaves like those of this specimen on the churchyard wall at Norton are are very frequently encountered. The wine coloured variation is due (and I am taking an educated guess here) to the presence of a chemical, one of the anthocyanins, which imparts hardiness to plants in exposed places, such as this wall top.

All the illustrations so far are examples of common ivy.

"Hedera canariensis" probably just a large-leaved
form (keys shown for scale) of  the common ivy.
Daventry 13 December, 2014
The Canary Ivy, Hedera canariensis, is also very widely grown. It really does hail from the Canary Islands - islands named after dogs (canis) incidentally, not birds -  and is usually grown in the variegated form shown, again from a car park in Daventry. Recent research suggests that is merely a rather large-leaved form of the common ivy and does not merit specific status.
Ivy, bearing flower buds. Daventry.  13 December, 2014

I have, on several occasions, mentioned the fact that common ivy has a very long - September to December - period of flowering, with the fruits ripening early in the new year and providing very welcome fare to many birds. Even so I was astonished to find this ivy specimen with its flowers still in bud! 

Again it was in the same Daventry car park, surely now a mecca for hederophiles. (Incidentally I made that word up only to then Google it and find it really exists - "an ivy-lover". How odd.)

Do I grow any ivies? Not on your Nelly! They're fine confined to pots but when Chris and I lived in Byfield we waged a never-ending war with it, as did neighbours who were similarly overwhelmed with the stuff.

I'll leave the final words to John Clare:

                       Save grey-veined Ivy's common pride
                       Round old trees by the Common side,
                       The hedgers toil oft scare the doves that browse
                       The chocolate berries on the Ivy boughs.

                                         Clare's Shepherd's Calendar, 1827

Wednesday, 10 December 2014

Pole dancing

Now I've got your attention!

I had to invent a catchy title as nothing of great moment has come to my attention over the last 72 hours, but my readers - both of them - will be demanding a dose of my deathless prose.

A biting westerly greeted me as I got out of my car in Byfield. I had volunteered to deliver a batch of leaflets around the village. At least they gave me an excuse to visit a few gardens as I struggled to control the paperwork in the buffeting wind. 

Hebes were bravely flowering along Westhorpe Way. In the early years of the 20th century Hebes were all regarded as species of Veronica, but in 1929 the botanists Cockayne and Allen put the cat among the pigeons by arguing that the shrubby species, mostly hailing from New Zealand, should be placed in a separate genus as Hebe. Their arguments were generally accepted and they began to appear as Hebes in plant catalogues, etc. Unfortunately, a few years ago Prof. Garnock-Jones and colleagues at Victoria University used DNA and cladistic analysis to show that Hebes should probably be regarded as Veronicas after all. The problem still ferments and the return to Veronica is being resisted in many quarters.

Whatever we call them these shrubs are extremely valuable in the garden and with careful selection can provide colour for most months of the year.

If Hebe/Veronica shrubs are eye-catching then Pellitory-of-the-wall, Parietaria judaica, could hardly provide a greater contrast. 

Parietaria judaica at the base of a wall.
Byfield, Northants. 10 December, 2014
This herbaceous member of the Nettle Family (Urticaceae) is very appropriately named for it does indeed grow abundantly at the foot of walls almost everywhere except in the busiest of city centres. The generic name, Parietaria, actually means 'wall-dweller' and the name was bestowed upon the plant by Pliny. Its tiny flowers are open even at this time of the year. The fact that there are few insects around is of no consequence as the flowers are wind pollinated. One leaf (near bottom right) bears a dark blotch with a pale centre and is almost certainly the 'mine' of the fly Agromyza anthracina.  This is interesting as the mine, though recorded from the related stinging nettles, does not appear to have been previously recorded from Pellitory-of-the-wall.

Another wall-dweller, Kenilworth Ivy, aka Ivy-leaved Toadflax (Cymbalaria muralis) gallantly bore a few flower buds but conditions will need to change significantly if they are to open. The word 'muralis' means, 'of walls' and is therefore also quite appropriate.

Bittersweet, Solanum dulcamara.
Byfield, 10 December, 2014

Yet another appropriately-named plant was in fruit nearby. This is Woody Nightshade or Bittersweet. The Latin name is Solanum dulcamara, with 'dulcis amara' meaning sweet-bitter. The fruits are clearly intended to tempt birds but I've a feeling that they come some way down the thrush's list of "Berries I want for my Christmas Lunch". Although related to Deadly Nightshade it is only mildly poisonous - and obviously not toxic to birds.

It can pop up almost anywhere although the usual habitat is a hedgerow, as John Clare observed:

                                 And scrambling up the hawthorn's prickly bower,
                                 For ramping Woodbines and blue Bitter Sweet.

                                                                                     Village Minstrel, 1821

Also being ignored by birds - although a really cold snap will change things - were the fruits of Roast Beef Plant, Iris foetidissima

Iris foetidissima, The Twistle, Byfield.
10 December, 2014

Like the Bittersweet, this is almost certainly bird-sown. It is a native British plant but in Northamptonshire it is best regarded as a neophyte, i.e. a plant introduced and naturalised in the county since the year 1500. It occurs all around Byfield, so certainly the birds do eventually consume the berries, with the seeds of course passing undamaged through the gut.

Funaria hygrometrica on a wall-top.
The Twistle, Byfield, 10 December, 2014
And, as far as flowering plants were concerned, that was about it. I did pause to photograph a patch of the distinctive moss Funaria hygrometrica atop a wall. The spore-bearing capsules are a bit like a drooping pear and are unusually large for the size of the plant. They also tend to point in all directions. Very common, a patch of grit or gravel suits it and, oddly, it often seems to occupy the site of a former bonfire. It can also be a nuisance in garden centres where it often invades the pots of plants.

Leaflets safely delivered I set off home.

Saturday, 6 December 2014

Splendid spurges

Euphorbia is a remarkable genus of plants containing over 2000 species (2420 according to Encyclopedia Britannica). We have about a dozen or so native to Britain, with several other species more or less naturalised. 

The genus contains plants enormously varied in form, with some succulent species resembling cacti and others fairly described as trees. Despite this variation the flowers are generally instantly recognisable, with a female and several male flowers being clustered into a small group known as a cyathium. All species also bleed a poisonous milky juice when damaged. In the shopping concourse of central Milton Keynes some of the very large cactus-like Euphorbias can be identified if a pin is surreptitiously used to pierce the tissues; milky juice quickly oozes out. It will come as no surprise to learn that the Rubber Tree is a member of the Euphorbia family but belongs, as Hevea brasiliensis, to a different genus. A slightly less obvious member of the family is Castor Oil, Ricinus communis.

Here in Northamptonshire a number of Euphorbias, generally known as spurges, are native, with several species being common. The Wood Spurge, Euphorbia amygdaloides, is quite easily found in woodlands on limestone in the north-east of the county and was familiar to me when I was based at RAF Wittering. It is rather common too around Byfield, but here it is probably a garden escape.

Turkish Spurge in a Byfield garden, with the bright red
leaves of  Photinia davidiana in the top left-hand corner.
18 March, 2014

An attractive subspecies, E. amygdaloides ssp robbiae, often called Turkish Spurge, is commonly grown in gardens and may occasionally escape. It was early to flower in Byfield, making a vivid splash of lime-green in borders. 

Musca autumnalis on Turkish Spurge.
Byfield, 8 April, 2014

Like most (all?) spurges, E. amygdaloides 
receives numerous insect visits. Here a male Lesser House Fly, Musca autumnalis, is imbibing nectar.

When living in Byfield I grew the Cypress Spurge, Euphorbia cyparissias. It is probably a British native but is certainly not so in Northamptonshire. With its feathery foliage it is a pretty plant for the rock garden but introduce it at your peril; it has long creeping rhizomes and can become very invasive, sometimes escaping on to rough ground. I won't be growing it here in Daventry.

Cypress Spurge. Byfield, 8 April, 2014

The wise gardener will confine Cypress Spurge to a sink garden or a similar container. In the accompanying photograph the gardener has taken the risk, planting it in a border with a pretty Pulmonaria.

Another spurge in my Byfield garden was Myrtle Spurge, Euphorbia myrsinites. It is a splendid plant and has been awarded the A.G.M. We bought a plant on a visit to Beth Chatto's lovely garden near Colchester but left it behind in Byfield.

Myrtle Spurge, Euphorbia myrsinites, in my garden.
Byfield, 23 March, 2014

From south-east Europe and Asia Minor, it is a sprawling, slightly succulent plant for a sunny spot. It is an easy-going species providing it gets plenty of sunshine and is in well-drained spot. I grew it in gravelly soil where it thrived.

A closer view shows the flowers in the form of a cyathium, typical of the genus.

Caper Spurge by a track in Byfield.
9 May, 2014
The Caper Spurge, Euphorbia lathyrus, is a curiosity with its stiff, opposite leaves in four vertical rows giving it an artificial look - a tall (up to 4 feet) plant made from a kit! It cropped up from time to time in my Byfield garden from an unknown source but the seeds are suspected of remaining viable for many years so may have pre-dated our move there. A hairless biennial, it may be native in some parts of England but is usually encountered as a plant on waste ground. The fruit look like capers and there is some evidence that they have been used as caper substitutes in the past. However, they are very bitter and all spurges are poisonous, with some fatalities known. Like many spurges, the seeds are initially dispersed by an exploding fruit capsule. Spurges are myrmechororous plants: following the bursting of the fruit their seeds are further dispersed by ants. Each seed has an oily structure attached to it known as an eliaosome. The oily material is attractive to ants who will carry the seeds away, helping to disperse them and perhaps even burying them.

With lots of spurges found in Britain I will mention just one more. The Sun Spurge, Euphorbia helioscopa, is a weed - but I consider it rather attractive. I have cultivated three allotments over the years, and Sun Spurge has occurred in all of them. Although generally regarded as a native to Britain it is probably an archaeophyte - a plant likely to have been introduced over 1500 years ago. In this case,  as with many other archaeophytes it may have arrived on these shores as a crop impurity, perhaps as far back as Neolithic times.

Perhaps we shouldn't forget those which are of importance to the florist.

Euphorbia milii is regularly seen in florists' windows, as was the case with these I photographed in Daventry. This species develops extremely prickly stems and is sometimes sold as 'Crown of Thorns'. However it can hardly have been Christ's crown of thorns as this species hails from Madagascar.

Now, with the approach of Christmas, one of the most familiar of all Euphorbias forces its way into our consciousness - except that most people probably aren't aware that it is a spurge. I refer to Poinsettia, Euphorbia pulcherrima. The word 'pulcherrima' is the superlative of pulchra - beautiful, and clearly people do find it very attractive. Strangely, the origins of this plant are not clear, although Wikipedia suggests Mexico and Central America. Visitors to the Mediterranean region will find it growing on waste ground (if, like me, they like to like to poke around in such areas) where it often forms quite a large shrub.

Altogether the genus Euphorbia is of great interest and identification of the many species provides a challenge to the holidaymaker when visiting southern Europe.