Monday, February 28, 2011

Lottery Odds























This is a female flower of a hazel Corylus avellana. In about six months time it will have developed into a cluster of hazel nuts but for now, at the base of those beautiful carmine red stigmas there are female egg cells, each waiting to be fertilised by a pollen grain that will land on one of those stigmas, germinate and produce a microscopic tube that will transport the male nuclei down to the site of fertilisation. First, though, the pollen has to reach the stigmas - and that is a very chancy business.


Tap a twig covered in dangling male catkins on a still day and they'll release a cloud of pollen grains that will hang in the air for a second then disperse. If there's any kind of wind (and there usually is in spring) they'll be whisked away immediately, diluted in a vast volume of air and fall to ground who knows where - or maybe be destroyed by rain. The chances of one actually landing on a receptive stigma is small. Very small. Which is why wind pollinated trees like hazel need to be so profligate when it comes to producing pollen.

For every female  egg cell, embedded deep within this bud, it has been calculated that the tree produces 2,549,000 pollen grains. So next time someone uses the phrase 'the economy of nature' and waffles about how living organisms are 'perfectly adapted' there can only be one response: nuts. Hazel nuts.

Sunday, February 27, 2011

Spring Greens


These golden saxifrage flowers are amongst the first to appear in spring and even though they are green (except for their yellow stamens) they are a very welcome hint of what is to come. These were growing beside a little tributary of the Tees, downstream from Egglestone bridge, on Saturday.



















There's fresh new green growth everywhere - these are the new shoots of silky wall feather-moss Homalothecium sericeum creeping out over their rocky substrate, in Teesdale.....




... and amongst last autumn's decaying leaves in a beech wood these pristine cuckoo pint leaves were unfurling.

Saturday, February 26, 2011

Snowdrops


Snowdrops were late putting in an appearance this year. I've often found them around here in flower in mid-January, but the ground was still deep frozen at that time.Now they are at their best and today we saw some very fine displays in Teesdale. It's a plant that's most common in river valleys around here, no doubt because the small bulbs that proliferate after flowering are swept down river and thrive in the alluvial soils when they are stranded after flood waters recede. This was one of many well established patches in the woodlands beside the River Tees, between Egglestone and the Meeting of the Waters, where the Tees meets the River Greta. There were even a few honeybees around, visiting the flowers, in this afternoon's sunshine.


It's unlikely that snowdrop is a native British species. It comes from milder parts of Europe and is what would be known today as an alien species. It is known to have been cultivated in gardens in 1597 but the first record of it in the wild only dates from 1778. Today most people look forward to the appearance of the flowers in the wild in late winter but if it was a new introduction, rather that one that has been here for at least four centuries, no doubt there would be a lot of press hysteria about 'yet another alien species invading our countryside'. I wonder how many garden species that are currently escaping into the wild will be viewed with similar affection to the snowdrop four centuries from now?


Snowdrops are often associated with churchyards and it may be that they were often deliberately planted there because their pure white flowers are associated with Candlemas, the Feast of the Purification of the Virgin Mary, which takes place on February 2nd., when the plant is always in flower. These plants were photographed in St. James Churchyard, just outside of Hamsterley village on the edge of Weardale, this afternoon.


As we were leaving (as you can see from the weak winter sunshine shadow, at 2 o'clock) I noticed this sundial on the porch of the church. The inscription at the top reads "Man Fleeth as it were a Shadow" - a timely reminder that at this time of year, on the threshold of spring, there is so much to see and so little time....."


Thursday, February 24, 2011

Hairy Snail

One of my project students, Alice Rowland, found this juvenile hairy snail, Trichia hispida, when she was surveying some grassland in Durham University Botanic Garden yesterday.
It's only about 5mm. in diameter and shows the hairy protrusions on the shell rather well. These wear away as the snail ages, presumably lost as it drags its shell through the grass.

Friday, February 18, 2011

Feeling the Pinch: Earwigs

I found this fine specimen of a male earwig Forficula auricularia under a rotten log today. You can tell it's a male by the curved pincers on the tail - the female's are much straighter. Earwigs can fly and have exquisite fan-shaped wings but they are tightly stowed away under those little wing cases and are very rarely unpacked. When this one suddenly found itself in the daylight its first instinct was to ....

... crawl into a crevice, so that .....

... only those tail pincers protruded, capable of delivering a painful nip - although their other purpose is to clasp the female's pincers during tail-to-tail mating. Somewhere the female would have been hiding away guarding her eggs through the winter and when they hatch in spring she'll continue to guard the young during their early stages of growth - compared with most insects, earwigs are very attentive mothers.

Thursday, February 17, 2011

Millipedes

Habits developed in our formative years often stay with us for life and as a kid I could never resist turning over logs and stones to see what lurked underneath - and now, over half a century later, I still can't. I found these two millipedes under a rotting beech log yesterday. The first is the flat-backed millipede Polydesmus complanatus, which superficially looks like a centipede but if you look closely you can convince yourself that it has the millipede's trademark two-pairs-of-legs-per-segment. Flat-backed millipedes have a reputation for being fond of strawberries, which doesn't endear them to gardeners.

The second is the aptly-named snake millipede Cylindroiulus punctatus, coiled up like a serpent.

There is a wondertful YouTube sequence of rather more spectacular species of millipede featured in David Attenborough's Life in the Undergrowth series here.

Backstone Bank Wood



Today's Guardian Country Diary describes a late winter walk from Salter's Gate, high on the moorland above Tow Law in County Durham, down to Tunstall Reservoir and Backstone Bank wood. The most picturesque way to approach the wood is to first follow the route of this old railway line, part of the old Stockton and Darlington railway that was opened in 1845 to carry passengers and coal to the ironworks at Consett. The line closed in 1939 but it must have been a great train ride in its day ....




... with wonderful views down to the reservoir, built in 1879, .....

... and across wild moorland of Wolsingham Park Moor.

When you leave the rail track and follow the stony path downhill it takes you down past larch and spruce plantations, that have a wonderful scent of resin on a winter's day.



After heavy rain, all the way down you are never far from the sound of water cascading down from the hillside in the feeder streams that drain into the reservoir

...until you reach Backstone Bank wood, an ancient semi-natural woodland of oak, holly and birch that's now an SSSI.

The path through the woodland skirts the edge of the reservoir and is popular with birdwaters. There are sandpipers here in summer, geese and ducks on the reservoir and woodland birds that include redstarts and pied flycatchers. This, incidentally, is the point where we crossed paths with that magnificent pheasant that I mentioned in an earlier post.

At this time of year the brightest green is confined to the woodrushs - still flattened from the winter snow - and new growth of mosses.

The humidity makes this a good spot for lichens like this Cladonia...

... and in late winter many mosses, like this Polytrichum species, produce new growth before the leaf canopy develops in spring and casts them into shade.


















The oaks are rooted in poor soil in a severe climate so growth is very slow. Near the end of the walk through the wood we came across this stump that had been cut, presumably to remove a tree that had blown down in the recent gales. We gave up counting the annual rings after we got to 100 but they are each notably narrow - testament to the short growing season.

When you emerge from the wood the path crosses the dam wall, with this view of water overflowing and cascading down the spillway into Waskerley Beck, which must have extraordinarily well oxygenated headwaters. It eventually flowers into the River Wear at Wolsingham, at the bottom of the valley.

Monday, February 7, 2011

Everlasting

I hope I look this good after I've been dead for almost a year.

This is one of last summer's carline thistles Carlina vulgaris, growing up at Salter's Gate near Tow Law in County Durham. I usually associate this plant with coastal habitats, but here it grows on the embankment of part of the old Stockton and Darlington railway line that carried coal from the collieries of Crook to the ironworks furnaces at Consett.

I'm amazed that the flower head is so well preserved, taking into account that it would have been buried under a metre of snow for several weeks in January. Those grey, spiny bracts continue to open and close over the central disk of dead flowers, depending on the weather - on wet days they close. I have a copy of Flowers and Flower Lore, written by the Rev. Hilderic Friend and published in 1886, that mentions that continental carline thistle seed heads were once nailed above the door of houses as indicators of the state of the weather, much as people have used seaweed or the opening and closing of pine cones for the same purpose, with the thistle closing at the approach of humid weather preceding a downpour.

The author also gives an interesting derivation of the Latin generic name, Carlina, which is supposedly a Latinised version of Charlemagne. "The story goes", he writes," that when the Emperor was on one occasion engaged in a  war, a pestilence broke out amongst his army, which carried off a large number of his men. This so troubled Charlemagne that he prayed to God for help, and in answer to his prayers an angel appeared and shot with a cross-bow, telling the Emperor to mark the spot where the arrow fell. The plant which the arrow indicated [carline thistle] would, the angel said, prove the best of antidotes, and stay the raging of the plague."

Meanwhile, in my 1934 copy of Wild Flowers in Literature (I seem to have accumulated a lot of obscure plant-related books) author Vernon Rendall mentions that carline thistle acquired its name from the Scottish word for a witch - a carlin - as in Robert Burns poem Tam O'Shanter:

As Tammie glowr'd, amaz'd, and curious,
   The mirth and fun grew fast and furious;
The Piper loud and louder blew,
   The dancers quick and quicker flew,
The reel'd, they set, they cross'd, they cleekit,
   Till ilka carlin swat and reekit,
And coost her duddies to the wark,
   And linkit at it in her sark!

So there you have it .... is it named after an Emperor or a witch? Either way, it's a memorable plant - especially if you happen to sit on one when you're having a picnic...


Saturday, February 5, 2011

Fine Feathers

We came face-to-face with this fine cock pheasant when we were walking through Backstone Bank Wood, on the edge of Tunstall Reservoir in Weardale this morning. Just as we crested a ridge in the path, there he was, decked out in magnificent feathers and a sporting a threatening countenance - probably because he was comfortable sitting beside the path in the sun and resented being disturbed. Pheasant rearing is becoming increasingly popular around here and these birds have zero road-sense, sometimes dawdling around in the road pecking grit. I suspect as many end up as road-kill as are shot.

A little further around the reservoir we found this muscovy duck preening its beautiful metallic-hued plumage, enjoying the weak February sunshine and maybe dreaming of warmer weather in its native Mexico.

Tuesday, February 1, 2011

Hedge Laying

Here's a sight that you don't see very often these days - a newly laid hedge. I found this old picture, that I must have taken fifteen years ago, amongst some old colour transparencies. The fresh, new cuckoo pint leaves at the bottom of the hedge show that it was a very early spring day and I can remember stopping the car to take the picture, somewhere between Kirkby Stephen and Sedburgh in the Howgills. This is a very laborious method of hedge management but when hedge laying is well done it produces a stock-proof barrier that will last for decades with only minimal maintenance. Young hawthorn stems are partially severed, bent over and then tied into stakes, then...


... when spring arrives vigorous new, prickly shoots grow up through the laid stems and produce a living, interlocking barrier. There are some very fine examples to be seen on the National Hedgelaying Society web site. It must be hard work, tough on the hands with all those hawthorn spines, so I guess it's no wonder that flail cutting hedges with a tractor has taken over, but although that keeps hedges in shape it can never produce the dense growth at the bottom of a laid hedge that stops a sheep pushing its way through. Annual flail cutting also tends to remove all of last year's young shoots that bear flowers buds - so no flowers for insects in early summer or haws for the birds to feed on in autumn.


You can often see old hawthorns that were once part of hedges that were laid in the distant past. The horizontal branches with vertical growths are a tell-tale sign ...
















Long ago, someone must have spent several days laying this old hedge ......























... and you can still see the legacy of their work in the distinctive silhouettes of these ancient hawthorns.