Sunday, July 23, 2017

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  

Saturday, July 22, 2017


It's a sign of the high summer when harvestmen appear in our garden. Initially I though this was Leiobunum rotundum, until Richard Burkmar (see comment below) pointed out that it's an invasive, non-native species called Opilio canestrinii which was first documented in Britain in 1999.This species has remarkably long black legs, like L.rotundum, but there is an orange ring around the trochanter ('knee') that I hadn't notice. This male, sunbathing on a leaf in the late afternoon sunshine, is in pristine condition, probably having just reached maturity. Females have a darker saddle-like marking on their dorsal side.

The longest legs are the second pair and key senses of taste, smell and touch are located on these. If you watch them walking through the undergrowth you can see them using these to explore their surroundings.

Harvestmen often lose a leg of two, shedding them if they are grabbed by a bird or caught in a spider's web, and this isn't too much of a problem unless it's the second sensory pair - then they are in more serious difficulties.

For more harvestmen (including pictures of a female Leiobunum rotundum) on this blog, click here.

Opilio canestrinii has spread northwards quite widely since it was first found in Essex eighteen years ago. The Spider and Harvestman Recording Scheme web site (click here) shows that it has reached as far north as Inverness. 

My guess is that it arrived in our garden via a plant from a garden centre. The wholesale and retail garden plant trade provides perfect distribution network for newly arrived arthropod species like this.

Friday, July 21, 2017

A very hairy gooseberry

All over the North Pennines there are traces of small settlements - usually mining communities or sometimes farmsteads - that have long since fallen into ruin. In some cases all you can see is a few piles of stones and the rectangular outline of building foundations, but often you can also find botanical traces of past gardens.

The commonest edible plants in these are rhubarb and gooseberries, which persist for generations, long after the gardeners who originally planted them have been forgotten. At this time of year the gooseberries start to ripen and I always make a point of tasting these, which mare mots likely to be forgotten varieties that are no longer cultivated. There are also scattered bushes well away from gardens, that would have been bird-sown. There is a large gene pool of feral gooseberry varieties out there in the countryside and maybe there might even be some that are resistant to diseases like gooseberry mildew.

This unusually hairy example was growing through an old wall in Teesdale and ripens to a deep ruby red. Its fruits are exceptionally sweet, though you need to rub off those hairs first it you want to eat it uncooked. It probably closely resembles the wild species that originated in continental Europe and which lost most of its bristles during cultivation.  If it was stewed or used to make chutney (gooseberries make excellent chutney) then they wouldn't matter too much.

I've rooted a cutting of this one, that's now growing in my garden. 

Apparently, gooseberries were first domesticated in the Middle Ages and there are records of plants being imported from France in 1275 for planting in Edward 's garden in the Tower of London.

Growing goooseberries competitively, to see who could produce the largest fruits, became popular amongst Lancashire weavers in the 1740s and the heaviest fruits weighed in at over 50 grams, over seven times the weight of the wild ones. By the early 1900s almost 1000 named varieties existed, cultivated by gooseberry clubs.

There is still an annual gooseberry growing championship at Egton Bridge near Whitby in North Yorkshire, which you can read about by clicking here. This year's show is on 1st. August.

The world record currently stands at 62 grams.