Sphagnum (bog moss) spore capsules

I don't often find spore capsules on bog moss Sphagnum species but they are well worth looking out for because they have a remarkable way of discharging their spores. 

They look like chestnut brown spheres, that swell and darken as they age.

When they mature you can see the lid. At this stage they remind me of tiny ginger jars. Gas pressure builds up inside as they age, and when the wall begins to dry out it shrinks. Eventually the pressure within  becomes so great that the capsule explodes, blowing the lid off and sending a column of spores into the air.

You can watch a video of this explosive 'air gun' mechanism  by clicking here

Moss pop-guns

It's not very often that I find bog moss (Sphagnum) bearing spore capsules. They are easy to overlook because they are not raised on a long stalk (seta) like the capsules of many other British mosses.

I found these on cushions of Sphagnum growing in a little hillside mire near Wolsingham in Weardale. I'm wondering whether it may have been the very dry spring followed by wet mild weather that triggered rapid growth and their formation.

The capsules remind me of small, round ginger jars.

They are unusual because, unlike most moss capsules that shake spores out through pores or peristome teeth, these literally explode.

As the capsules mature they lose water and the air inside them becomes pressurised. As the walls contract the capsules change shape, from spherical to cylindrical like the rearmost in this photograph. Eventually the lid blows off, sending a mushroom cloud of thousands of microscopic spores, in a vortex like a smoke ring, about ten centimetres into the airstream.

You can watch a high-speed film of the whole process by clicking here and here  

Wildlife viewed through beer goggles: 6. Is this the world's first moss-themed beer?

Still in pursuit of wildlife-themed beers (click here for earlier examples), here's a complete novelty. I suspect that this must be the world's first moss-themed beer.

Old Sphagnum has been brewed by the Allendale Brewery to celebrate the tenth anniversary of the Peatland Restoration Scheme by the North Pennines Area of Outstanding Natural Beauty Partnership.



This is Sphagnum, the wonderful moss that grows from the top, dies from below and produced deep peat deposits that - amongst other attributes - lock away atmospheric carbon.



And here, high in the North Pennines in Weardale, is a peaty pool, partially full of Sphagnum, that is a superb habitat for all sorts of wildlife.



Sphagnum absorbs water like a sponge, thanks to these highly specialised leaves that are formed by a network of living cells separated by dead, empty cells that hold water.



Here they are under the microscope, showing that network of living cells (green) and the hollow dead cells in between that hold water.

The Peatlands Restoration project aims to reverse past damage from moorland drainage, that has killed the Sphagnum and led to rapid peat erosion. 

This is the only moss-themed beer that I've ever encountered and has instantly become an indispensable addition to any bryological field trip.

Where the Bodies are Buried ...

Today's Guardian Country Diary describes a field excursion with some Durham University biology students to Chapel Fell, between Weardale and Teesdale in Co. Durham 


We were lucky from the weather and the views were stunning, although there were still patches of snow on the ground so it was pretty bracing up there. This is just about the last place in the local landscape to show signs of spring but if you take your eyes off the view and look at the ground under your feet there are plenty of signs of growth in the upland mosses. Some beautiful lichens thrive here too.

Bogs like this are deep pools filled with Sphagnum moss and are a potential death trap. Stroll onto this fine green 'lawn' and you'd instantly disappear up to your neck (at least) in ice-cold water. 

Sphagnum moss is a living sponge that retains vast amounts of water, thanks to its unique leaf structure which you can see by clicking here. Once you get about a metre down from the surface it's pretty anaerobic and preserves biological materials (like drowned bodies) extremely well. You can read about some fine examples of corpses exhumed from peat bogs by clicking here.

In more open patches of water the moss takes on this very attractive starry appearance.

Sphagnum species identification is a specialist skill (there are around 36 species listed in the latest field guide) that I've never mastered and there are several species up here that would keep dedicated bryologists occupied for some time, including ...

.... this delightful claret-coloured example.

One day I'll learn to identify them, using his excellent key.

Polytrichum species thrive on the drier banks ....

.... and  this one,  which I think is Hylocomium splendens, has intensely red stems bearing yellowish leaves and does well amongst the heather stems that have yet to show much sign of new growth. 

This is also home to some fine lichens (mostly Cladonia species) .....

I think this may be Cladonia diversa