Easter Sunday walk along the river Wear

Probably the best weather that I can ever remember for an Easter Sunday. We took a walk along the south side of the river Wear, between Wolsingham and Black Banks plantation at Harperley.

Reassuring to find that the weird flower spikes of toothwort Lathraea squamaria were coming up again under the old coppiced hazels, where we've known them for nearly 40 years.

There's something vaguely reptilian about these parasitic flowering plants that siphon off all their nutrients from the roots of hazel.

You can read more about the strange physiology and folklore of toothwort by clicking here.

This is the plasmodial stage of the slime mould Reticularia lycoperdon [recently renamed Enteridium lycoperdon], probably only about a day away from turning into the sporulating stage. In the plasmodial stage it creeps over the alder tree trunk surface, digesting bacteria, then it forms a parchment-like skin (for pictures click here) enclosing countless dark brown spores. When the skin ruptures they are dispersed on the wind, then germinate into minute amoeba-like organisms that eventually aggregate back into this creeping plasmodial stage, which is most often seen in spring.

I found my first wild primrose of the season growing at the base of an ash tree, and ....

... hundreds of butterbur flower spikes had appeared along the riverbank in the last week.

Elm flowers. A mature elm tree in full bloom was a wonderful sight, with its crown a haze of purple, but it's one we are unlikely to see again, thanks to Dutch elm disease. Young elm trees that have regenerated from the roots of dead stumps are common enough though.

The beautiful juvenile female cones of larch, waiting to be pollinated.

Artefacts of autumn: a hazel nut neatly split in two by a grey squirrel and the stone of a fruit (wild arum?) nibbled by a field mouse.

A rather tatty peacock that had safely made it through the winter and was sunbathing on an old plastic bag.

A pair of goosander on the river. Their behaviour changes in spring. A few weeks ago they would have flown before I could get close but once they are paired up and have identified a hollow tree to nest in they are reluctant to leave their territory.

A fantastic carpet of wild garlic leaves beside the footpath, that will become a sea of white in a few days' time when the flowers open.

Those trees at the top of the bank host a rookery, so we were accompanied by their cawing along this stretch of the walk.

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........... 

Slime Mould

 This is the slime mould (myxomycete) Fuligo septica var. flava, that we found on a rotting log at Smardale Gill National Nature Reserve near Kirkby Stephen in Cumbria on Tuesday. These are amazing organisms, that start life as microscopic amoebae that germinate from spores, slither over wet surfaces and ingest bacteria in their path. Ultimately they aggregate to form the slug-like slime mould, that continues to crawl and grow until it's mature - this one has just reached maturity and looks like miniature scrambled egg. What happens next is that it begins to lose water and produce spores that will blow away in the wind and germinate into new wandering amoebae, feeding and on the lookout for other amoebae that they can aggregate with.

This is the same organism, photographed about two hours later and if you double-click to enlarge the images you can see that its structure is already changing, from miniature scrambled egg to miniature yellow Brillo pad .... and soon it'll dry out and release its spores.

Slippery and Slimey

The current spell of mild wet weather has provided perfect conditions for this fine specimen of Suillus bovinus, a close relative of slippery Jack S. luteus, that we found around the roots of some Scots pines beside the South Tynedale Railway at Alston this morning.

The whole surface of the cap in this species is covered in a slippery mucilage. As the toadstool ages it gradually turns darker brown, but this specimen is the prime of life. The books say it's edible but I'm not tempted.....

 

Suillus is a polypore, releasing its spores down the narrow tubes that line the underside of the cap.
Slippery Jack is indeed slippery, but not in the same league as the organism that was creeping through the grass on the other side of the footpath.

This is the slime mould called Mucilago crustacea. Slime moulds, or myxomycetes, are amazing organisms and if they didn't exist science fiction writers would surely have to invent them. They begin life as individual microscopic amoebae that hatch from powdery spores that are released from the wrinkled surface you can see here. The amoebae aggregate and fuse together to form a creeping, translucent plasmodium, that moves across the surface of wet soil, grass, wood and rocks digesting bacteria and dead material that lies in its path.

If you look closely at the image above you can see the plasmodium - the translucent part, with thickenings that look like veins - stuck to the dead grass in the foreground and hanging in a blob slightly above and to the left.

This plasmodium is almost fully fed and its wandering days are over. The leading edge, seen here is already wrinkling, is beginning to produce vast numbers of spores on the surface of those convolutions and these will dry and blow away in the wind or be washed away by rain..... to germinate again and release swarms of amoebae

 You can find some very fine movies of the creeping plasmodial stage here and here

Slime moulds

These spectacular examples of the slime mould Reticularia lycoperdon are currently to be seen on the trunks of an alder, in the Long Alder Wood at Durham Wildlife Trust's Low Barns Nature Reserve at Witton-le-Wear. These are the most spectacular examples of this weird organism that I have ever seen. It begins life as a swarm of microscopic, amoeba-like organisms that slither over tree bark, engulfing bacteria. Eventually they aggregate to form these white, tear drop-like blobs that form a hard white skin and produce millions of powdery spores inside, that are dispersed when the skin ruptures. Each spore germinates to form another amoeba. Each of the white blobs here is about the size of half a tennis ball; I have never seen so many in one place. You can find out more about Low barns Reserve at http://www.durhamwt.co.uk/LowBarnsVisitorCentre.htm

and more about this slime mould at

http://www.discoverlife.org/20/q?search=Reticularia+lycoperdon