Monday, January 30, 2012

You Have Been Warned .....

This morning this seven-spot ladybird crawled out onto a foxglove leaf in our garden, near the bird table, and spent the whole day there. All day long it was surrounded by hungry blackbirds, hedge sparrows, chaffinches and starlings, all fossicking around in the undergrowth looking for something to eat - and the ladybird remained completely unmolested,which is, I suppose, testament to the deterrent effect of its warning colouration (or aposematism, as it's more scientifically termed). 


I was surprised that the ladyird had ventured out at all because the temperature has hovered around freezing all day, with intermittent sleet showers. I wondered whether it was dead so just before darkness fell I gave it a gentle prod, when it beetled off into the leylandii hedge. These much-maligned conifers provide an excellent overwintering site for insects like this.

Friday, January 27, 2012

Signs of Spring: Arum maculatum leaves



































There's a long way to go yet, and cold weather is on the way, but this is something I look forward to at this time of year - cuckoo pint Arum maculatum foliage spearing up through last year's dead leaves and beginning to unfurl.

Wednesday, January 25, 2012

Birch Brackets

























I found two typical bracket fungi that live on silver birches this afternoon, on some trees on the banks of the river Tyne near Wylam. This is the aptly named hoof fungus Fomes fomentarius. We tend to think of toadstools as here-today-gone-tomorrow organisms that appear overnight, shed their spores over a day or two and then wither away but bracket fungi like these are perennial, adding a new layer of spore- producing tissue (the hymenium) every season until the tree that they are digesting has yielded up all its available nutrients. During their long lifetime the brackets can produce millions of spores. Each successive layer of spore-producing tissue is marked on the surface of the bracket by a ring-like indentation, rather like the annual rings of a tree but visible on the fungal outer surface. The hymenium on the underside of this specimen, formed from thousands of pores lined with spores, shows signs of damage - probably from a slug.
























These two are old specimens, are probably moribund - their hyphae have exhausted the supply of nutrients they can extract from their host's wood, which by this stage has developed a crumbly texture akin to balsa wood.


 This is an old specimen of the most familiar bracket fungus growing on birch, the birch polypore Piptoporus betulinus, also known as the razor strop fungus on account of its past use for honing a keen edge on cut-throat razors. Young specimens tend to be cream-coloured but they go brown and become leathery as they age. 
























Bracket fungi like these are hosts to a variety of different insects that breed inside their tissues, so this is a food chain where plant tissue is being converted into fungal tissue which in turn is being transformed into animal tissue. If you harvest one of these old bracket fungi at this time of year and keep it in a container covered in muslin (which I've just done) you can expect to see a variety of different beetles emerge in spring and early summer - and if they do I'll post pictures of them when they appear.

Tuesday, January 24, 2012

Mosses - plants with teeth
























The developing spore capsules of wall screw-moss, Tortula muralis, spotlit by the low winter sun.



The capsules are still in the early stages of development but when they're ripe they'll shed their spores through a remarkable mechanism that involves the uncurling of a set of teeth, twisted like a screw thread, arranged around the mouth of the capsule. You can see them here.

Monday, January 23, 2012

Spurge Laurel





There are always landmarks in the changing seasons that I look out for and this is one that's particularly welcome at this time of year: spurge laurel Daphne laureola coming into bloom, a sign that spring is creeping a little closer. These lime green clusters of flowers always begin to open at about the same time as snowdrops bloom and depend on bees and butterflies that emerge on mild days for their pollination. In January, the plant is likely to be better served by these insects in southern England  than up here in the North East. The flowers have a faint fragrance, though nothing like as strong as some of the Daphne species grown in gardens.
























When I was a kid growing up in Sussex I used to see spurge laurel quite often in the beech woods on the South Downs but in North East England it's an uncommon plant - but relatively easy to spot in hedgerows at this time of year because it's evergreen. This one is growing in a hedgerow at Wolsingham in Weardale.


Later in the year it produces glossy black berries which are poisonous, but like many poisonous plants it has been used in herbal medicine in controlled doses. The 18th. century botanist and physician William Withering had a high opinion of its therapeutic properties. "Very happy effects have been experienced from this plant in rheumatic fevers", he wrote. "It operates as a brisk and rather severe purgative. It is an efficacious medicine in worm cases; and upon many accounts deserves to be better known to physicians; but in less skilful hands it would be dangerous, as it is possessed of considerable acrimony. The whole plant hath the same qualities, but the bark of the root is the strongest. Dr. Alston fixes the outside dose at ten grains"


Sounds risky, so please don't try this at home - even if you can find kitchen scales that are calibrated in grains. 


Incidentally, Dr. Charles Alston, 1683-1760, quoted by Withering above, was  lecturer in materia medica and botany at Edinburgh University and was the first person to produce opium from poppies in Britain, conducting experiments with it on animals and drawing attention to its potential for pain relief and drug-induced feelings of well-being.

Saturday, January 21, 2012

The Spider who was Determined to be on the Web.























There's quite a varied spider fauna on the window ledge in the room where I work (examples here and here) and this very small zebra spider put in an appearance at the beginning of the week, exploring my desk and even my computer keyboard. Since it seemed so eager to get itself on the web, I thought I'd oblige. The pictures are not very good because it really is tiny - just a few millimetres long - and these are small sections of the whole frame.























Zebra spiders don't actually spin a web to capture their prey. Instead they stalk it then leap onto it from a distance. They can do this with remarkable accuracy, thanks to the two large forward facing eyes that are somewhat akin to a pair of binoculars.


There are two further pairs of smaller eyes on either side of the central pair, so this arachnid has almost 360 degree vision. I find it hard to imagine how its relatively simple brain can process, prioritise and respond to all that visual information. It must be like watching six TV screens at once.


As you can see from this angle, its difficult to creep up on a zebra spider from behind - there's a rearward facing eye watching both flanks.

Although zebra spiders don't spin a capture web they do anchor themselves with a thread of silk, ready for instant escape ....... which is what my specimen did when I got too close with the camera ..... it bungee-jumped from the window ledge then climbed back up its escape thread when it thought the coast was clear. The other role of this escape thread is as an emergency safety line, in case the fly that it leaps on carries it aloft before the spider can subdue its victim.

Friday, January 20, 2012

Winter Aconites


I found these winter aconites Eranthis hyemalis just coming into bloom near Wolsingham in Weardale yesterday, amongst trees beside a stream. I've known them from this spot for 35 years and they must have been planted there long before that. I've tried to establish them in my own garden on a few ocasions with no success - maybe they need a little more neglect and some sheep hooves to churn up the soil in winter...



They come from southern Europe but are well naturalised in quite a few places around here. I've seen them in hedgerows in the Tyne valley, near Corbridge.


These early flowers are a little weather-beaten. They are unusual because the structures that look like yellow petals are really coloured sepals and the real petals are reduced to small, rolled-up green tubes that fill with nectar, located within the flower below the stamens - you can see one clearly at the 5 o'clock position in this photo. Hellebores, which are fellow members of the buttercup family, have a similar floral arrangement. Both are early bloomers so I imagine that these 'vases' of nectar have evolved to lure the few pollinators that are around on early spring days, on the lookout for an energy top-up....

Thursday, January 19, 2012

River Wear, Wolsingham


Today's Guardian Country Diary describes a walk along the River Wear at Wolsingham in Weardale. Even though the riverbank woods look bare at this time of year there's always plenty to see along this stretch of river .....
























 ... like the exquisite filigree of cypress-leaved feather moss Thuidium tamariscinum. Many woodland mosses make a lot of fresh new growth during mild spells in winter, when more light can reach them through the leafless branches.


There are often some fine fungi along here too on all the decaying wood - like these velvet shanks.


When we had prolonged heavy rain in Weardale a couple of weeks ago and the river rose very rapidly and flooded its banks. It scoured away all the dead leaves but the dead sweet cicely flower stems - which are chest-high here in summer and smell of aniseed - remained rooted but were flattened by the water, leaving a contour map on he ground of the path of the current as it had swept around the tree trunks.


Above the high water mark of the flood there was still a thick layer of autumn's decaying leaves ...


...... with bluebell leaves already spearing through.



Closer to the river the retreating water had deposited a thick layer of silt, but the buried snowdrops that grow in profusion here early in the year had already forced there way up to the sunlight and started to bloom.
























When the water level falls if leaves behind these dark, temporary pools amongst the alders on the edge of the river. Sometimes there are fish trapped and the local herons are well aware of this - there are always heron footprints around the edges. In the spring toads breed in the pools and then it's a race against time for the tadpoles to develop before the pools dry up.


This stretch of river always has resident dippers and at this time of year they sing a lot, establishing their territory. It's amazing how you can always hear their song above the sound of the river - its pitch must have evolved to penetrate the background noise of the water rushing over a stony riverbed.
























The riverside woodlands are constantly raided by parties of long-tailed tits .....
























nuthatches ......
























..... and treecreepers, all looking for insects in tree bark crevices, while ........


...... this heron, evidently out of luck in the riverside pools, flapped away to try its luck on earthworms in the fields above the river.

Wednesday, January 18, 2012

Stemonitis fusca - joss sticks for forest fairies?



Slime moulds are interesting organisms but you couldn't really describe them as being beautiful (one of the commonest bears the name 'dog's vomit slime mould') - but this one is a little different. When Stemonitis fusca has finished crawling around and feeding in its plasmodial stage it enters its sporing stage and produces these cinnamon coloured structures, about a centimetre high. You can find   a wonderful movie of it on YouTube.


I've found it on a number of occasions on dead wood in forest plantations in Weardale. On the first occasion when I showed them to my kids (many years ago, when they were very young!) they were convinced they were looking at  'sparkler' fireworks for the forest fairies. Once they got to their teenage years they revised their opinion and claimed they were joss sticks for the forest fairies, who had clearly developed become hippies in the intervening years........... 

Tuesday, January 17, 2012

Winter Blossom and Bullfinches




I planted this Prunus subhirtella autumnalis about fifteen years ago and every winter at this time it graces the garden with these flowers on bare twigs. It begins blooming in November and reaches a peak in February, but one of the best things about it is that .....



.... bullfinches find its apparently inexhaustible supply of flower buds irresistible. Yesterday there were three cock birds like this one feeding on it, together with three females.






































This flowering cherry also diverts the birds' attention from the pear trees' buds further down the garden, so on the basis of its winter flower display, bird visitors and decoy attributes, planting it was a win-win-win strategy. 

Monday, January 16, 2012

Convolvulus hawk-moth (deceased)


I receive quite a lot of natural history specimens to identify, some live, some dead. I found this dead Convolvulus hawk-moth Agrius convolvuli specimen waiting for me when I went into work last week. It was in a plastic beer glass, covered in cling-film .......although it must have been deceased for some time ..... with new indication of who left it or where it was found, but I'm assuming it was local i.e. from Durham.

Even in death it's a magnificent insect and when it was alive and hovering in front of flowers it must have been truly spectacular. Those wings are each 4 inches long, making this one of the the largest British moths on a wing-span basis. Convolvulus hawk-moths migrate here from North Africa in late summer and this one must have benefited from the long, mild autumn before it expired.

The natural distribution of the species extends into tropical East Africa and right across Asia. There are records in the literature of it pollinating papaya and baobab trees in Kenya. Those that reach here, after a 1000+ mile migration journey, tend to feed on nectar from flowers of night-scented flowers like tobacco  and the caterpillars, which don't survive the winter here, feed on Convolvulus spp. leaves.



The proboscis of a convolvulus hawk-moth is something to behold. In his New Naturalist book Moths E.B. Ford (1955) mentioned that it can be three times the length of the body when fully extended. When this one died the proboscis contracted into a tight, brittle coil that I can't uncurl, to test the veracity of Ford's claim, but you can see here the slot between the eyes, on the underside of the head, where the proboscis normally sits.

In the newer New Naturalist book on moths by Mike Majerus (2002), he mentions that each compound eye of one of these moths has 27,000 facets. Hawk-moths certainly have outstanding low-light vision and can easily locate flowers by moonlight as well as by scent. There is evidence in the literature of some hawk-moths locating flowers by starlight on moon-less nights.

Convolvulus hawk-moths tend to spread up through Europe on their migration flights. reaching as far north as Norway in some years. It seems that the few that reach England cross the English Channel and most often turn up in the southern counties but Majerus also mentions that they regularly take refuge on North Sea oil rigs, so maybe these head north into Scandinavia then cross to eastern England via a North Sea route?

A magnificient moth ..... so thanks to whoever it was who left it for me to have a look at. Now I want to see a live  one and will be planting tobacco plants and lurking with a torch in late summer - ever the optimist!

Sunday, January 15, 2012

A Touch of Frost



At last we've had a photogenic frost. These are the frost-dusted fruits of stinking iris aka roast-beef-plant aka Iris foetidissima. It's a British native wild flower but not, I think, native to North East England. It's an excellent plant for a wild flower garden, holding onto its strikingly coloured fruits all through the winter. My plants are growing on a dry, sunny bank in the garden, under a hedge. Its common names come from the fact that its crushed leaves smell of roast beef - to my nose they have the over-the-top beefy aroma of beef-flavoured crisps. There are some pictures of the flowers here.


Back in the autumn the Norway maple tree at the end of our garden produced a massive crop of winged seeds that are now scattered all over the garden. If they were left to germinate and grow it'd be a forest in no time. They look attractive when they're welded to the soil with frost, though. Frost breaks they're natural dormancy and they'll germinate in late March. It's amazing how far they can travel - on just a moderate breeze I've watched them 'helicopter' 50 metres down the garden then fly over the house on an updraft.





































Some very fine ice crystals formed last night - these are on the surface of a sage leaf.

Saturday, January 14, 2012

Underground




































This is a lesser celandine Ficaria verna plant that was growing in our garden, which has already produced an amazing network of new roots. While we wait for new growth to appear above the soil surface in spring, there's a lot happening underground, out of sight . Once new growth begins in spring - even while the first new leaf is beginning to unfold - underground roots are making vigorous new growth. If you want to control the buttercups in your garden, now is the time to do it - don't waiting until spring, when they'll have produced very large root systems. 
























Lesser celandine survives the winter as a cluster of teardrop-shaped root tubers, filled with starch, and its this energy store that's used for new root growth, even before the new leaves become functional.


You can find more on the beautiful internal structure of roots here .....


.... and more on hidden characteristics of lesser celandine flowers here.

Thursday, January 12, 2012

A Brief (and very dubious) History of Chewing Gum























I was passing some wild cherry trees in Weardale this afternoon and noticed this ball of solidified gum exuded from a damaged branch of one of them. Prunus species tend to do this if they're wounded – plum and cherry trees in particular are prone to exude gum if they’re wounded. 

I vaguely remembered that this gum is supposed to be edible and when I got home checked it out in some early natural history books. Curiously the notion of its edibility seems to be based on the same original account,repeated more or less verbatim in books from the 18th., 19th., and 20th. Century (plagiarism has always been rife in natural history writing). It goes as follows:

Hasselquist relates that more than a hundred men, during a siege, were kept alive for near two months without any other sustenance than a little of this gum taken into the mouth sometimes, and suffered gradually to dissolve’.

That comes from William Withering’s 1776 treatise called A Botanical Arrangement of all the Vegetables Naturally growing in Great Britain..., which was the oldest source I could lay my hands on.

So who was the mysterious Hasselquist, who seems to be the original source of this persistently plagiarised information? It turns out that Fredrik Hasselquist (1722-1752), a Swede, was a contemporary of Linnaeus who travelled extensively in the Middle East during his all-to-short life.

I couldn’t find the original source of Withering’s quote on the web but did find another, even more improbable, account by Hasselquist of the miraculous nutritional qualities of chewing gum.

It comes fronm his book entitled Voyages and Travels in the Levant in the years 1749, 50, 51, 52, containing observations in natural history, physick, agriculture and commerce, particularly on the Holy Land, and the natural history of the Scriptures. Remarkably, its available to read on the web, here, courtesy of Google books.

In this passage he’s referring to gum Arabic rather than Prunus gum, but for gum chewers everywhere it's reassurance that, if you are caught in a difficult situation, salvation may come through mastication.

The Abyssinians make a journey to Cairo every year, to sell the products of their country......They must travel over terrible deserts ... the necessities of life may chance to fail them when the journey lasts too long. This happened to the Abyssinian caravan in the year 1750, when provisions being consumed, when they had still two months to travel... they were obliged to search for something amongst their merchandise, wherewith they might support life in this extremity, and found nothing more proper that gum Arabic. This served to support above 1000 persons for two months ... the caravan arrived safe in Cairo, without any great loss of people either by hunger or diseases’. 

Improbable maybe, but I've seen more outrageous claims made in the popular press about purported benefits of health foods.....

Meawhile, back to cherry trees - and you can read about their beautifully fragrant wood at this excellent new blog.

Wednesday, January 11, 2012

Rotten Antiques























I guess most of us would shy away from buying antiques infested with a wood-destroying fungus - unless  the agent of decay is this one. The green staining in this dead branch is caused by the green elf-cup fungus Chlorociboria aeruginascens (which used to be called Chlorosplenium aeruginascens) and the tinted wood was once used to make Tunbridge Ware - furniture inlaid with a  patterned veneer of different coloured woods. According to John Ramsbottom in his Mushrooms and Toadstools (New Naturalist, 1953) the green pigmentation is produced by a fungal compound called xylindeine and Ramsbottom mentions that patents had been taken out on a process to produce attractive green wood by artificially inoculating it with the fungus, so that cabinet makers wouldn't need to forage for it in the woods. I wonder if the process was ever developed and commercialised? The fungus is very common and widespread on a variety of different trees, including oak, ash, beech, hazel and birch and the tinted wood is commonly known as 'green oak'. The fruiting bodies look like small, cup-shaped green scales on the surface of the rotting wood, but they aren't produced very often so are not easy o find.

Tuesday, January 10, 2012

Bad Hair Day

























I found this amongst some old photos. My kids bought it for me for my birthday years ago... claimed it looked like me on a bad hair day ...I don't know whether you can still get them, but I hope you can.  All you needed to do was water his scalp and lush green hair grew. 

Monday, January 9, 2012

It's a catkin..... but not as we know it ...



































I found this strange hazel catkin when I was out walking along the River Wear at Wolsingham at lunchtime. Unlike the normal one on the left, this one has branched into seven separate 'tails' at the tip. Might have been caused by damage during the very early stages of its development last summer.

Monday, January 2, 2012

Microcosm


In winter, it's the smaller things that tend to capture your attention on country walks - like, for example, this miniature garden of mosses, lichens and fungi growing on top of a drystone wall at Stanhope in Weardale. In the space of a few square inches there are toadstools (haven't identified the species yet - can anyone help me out with some suggestions?); at least four species of moss; at least three species of lichen. If you really got to work with a hand lens I suspect you could probably double the biodiversity count for this tiny patch .......... and if you resorted to using a microscope, who knows how many! Below are two of the larger ones that I think I can identify.....



This (I think) is an Orthotrichum species although I'm not certain yet which one..... most probably O.anomalum.





































..... and his, with the distinctive hair-point extensions to the leaves and capsules that curl downwards into the moss cushion, is Grimmia pulvinata (with another moss on either side of it and Orthotrichum anomalum at the top and bottom).


It's a long time since I last tried to identify moss species.....................