Monday, 29 November 2010


Well, the snow that we were promised duly arrived, although we haven't been hit nearly as badly as other areas. This is the time of year to spend some time in anticipation of what next year will bring, and as I checked the Willow trees in my garden, I saw the sheaths of next year's leaves growing from the point where this year's leaf has been shed:

Willow leaf sheath
That's quite normal and I'd expect to see that happening at this time of year. What I didn't expect to see, however, is the catkin beginning to open:
Opening Willow catkin
I'd expect to see that happening around the end of February, but something has completely confused this particular tree because many of the catkins were in the same condition. This early opening will have a short-term adverse effect on the tree because these flowers will be destroyed by the frost, requiring the tree to make a second set of flowers later in the spring.

This, of course, will impact our willow-dependent moths and other insects. Bees such as Andrena clarkella are only seen during the normal flowering season for willows, and this tree might flower too late to support them. On the other hand, it might just be possible that some of the other dependent species could extend their season a little due to the later availability of some pollen and nectar.

In our natural environment nothing ever happens in isolation.

Wednesday, 24 November 2010

Seasonal images

We're expecting snow later in the week, and that kind of weather is often preceded by interesting morning skies. This is the view from my bedroom window this morning:

Croaghan Hill, 8am, 24/11/2010

Stormy weather had brought down some small branches, and I found this specimen of the lichen Xanthoria parietina:

The green and yellow cups look like tiny cup mushrooms, and that's exactly what they are: the reproductive components of lichens are controlled by the fungus. In this case the cups are purely fungal and produce only fungal spores. The spores are ejected to land some distance away and must land on the appropriate alga to form a new specimen of the lichen.

The Candle Snuff fungus - Xylaria hypoxylon -  grows on dead wood:

This nice little image of a Mycena growing in moss is tinged with more than a hint of sadness:

Mycenas are a tricky little group, and I'm sad to report that my friend and Mycena guru Gerry Shannon is no longer with us. He was a very jovial and enthusiastic mycologist who specialised in the LBJ's that we found. He will be sadly missed.

Wednesday, 17 November 2010

More moss

A rare bit of sun and I was out like a shot.

Wall-tops are the place to find a number of mosses including the very handsome Tortula muralis (guess where it got its specific name from).

Last year's capsules are still in place (those are the taller, brown ones), but if you look closely you can see the new ones emerging just above the leaves.

Tortula muralis capsules - old and new

Emerging capsules of Tortula muralis
To give some sense of scale, the new capsules are about 5mm long.

The rear walls of ditches are also rich in moisture-loving plants. The following shot shows at least two species of liverwort and one moss.

1) The thallose liverwort Conocephalum conicum
2) The moss Plagiomnium undulatum
3) The liverwort Plagiochila porelloides
Liverworts are either 'thallose' (flat and ribbon-like) or 'leafy', and we have one of each in the shot above. The area in the shot is about 20mm across.

Wednesday, 10 November 2010

Small but beautiful

As I mentioned the other day, we're moving into a good time to have a look at mosses. They tend to start making their spore capsules around now and they're often very attractive whilst the capsules develop and before they mature and dry off.

Polytrichum urnigerum
Capsules of Polytrichum urnigerum
Although they are considered to be some of our most primitive plants (spores vs. flowers, pollen and seeds), the life-cycle of mosses is rather complex, and it took me a while to work it all out.

There are two generations in the reproductive life-cycle: a vegetative stage (the green plants you see) and a dependent stage (the spore-bearing capsule and its associated stem [seta]). Spores are produced in the capsule and are dispersed by air or water (or, indeed, insects) and these each result in a male or female plant. Male plants produce gametes, which swim to fertilise the female egg. This fertilised egg develops into the seta and spore capsule, which are then parasitic on the female plant (capsules and setae have no chlorophyll, and therefore need to absorb food from the female parent). So each capsule-bearing 'plant' is actually two generations: the mother (with leaves) and the child (the capsule and seta). 

Setae of Ceratodon purpureus
All parts of a moss can be truly beautiful if looked at closely, but you really do have to 'get down to their level' both physically and metaphorically to appreciate just how beautiful they can be.

Mosses can be quite tricky to identify at first, with most needing microscopic analysis of leaves and some requiring examination of capsules. I have found, however, that once the initial identification has been performed, most specimens are readily identifiable in situ.

Mosses often grow in similar habitats to our other 'primitive' plants - liverworts and ferns - and also lichens.

Lichens are usually thought of as the flattish marks on walls and trees, but some of them appear to be quite leafy, as in the Peltigera family of Dog Lichens:

Fruit bodies of Peltigera hymenina
In common with all lichens, Peltigera are an association of a fungus and its trapped alga(e). The fungus provides the physical structure and the alga provides nutrients from sunlight. The orange fruitbodies shown above are purely fungal, and produce fungal spores in the same way as an independent fungus does.

(I'm just getting to grips with the new formatting tools)

Sunday, 7 November 2010

Back in action

The weather has been absolutely hateful for a couple of weeks, and it was good to get out in daylight for a change.

A Beech tree shed this huge branch a couple of years ago, probably due to a fungal attack by Ganoderma applanatum, which is all over the tree. Various fungi are now busy decomposing the dead branch and I took a few shots.

This is Stereum hirsutum which can be resupinate (flat and crusty) or can form continuous waves of brackets:

Some clusters were in tiered groups:

Neobulgaria pura is gelatinous throughout and is specific to dead Beech:

Last year I showed the Oak leaf-miner Ectoedemia herengi, which makes mines in 'green islands' in fallen leaves.

The mine has only just started to form and we're into November:

The tree would normally withdraw all chlorophyll from the leaves before shedding them, but leaves with Ectoedemia larvae retain some of the chlorophyll and the miners continue to use the food source, thereby extending their active breeding season. The mechanism whereby the larvae blocked the chlorophyll has been largely unknown, but recent research has revealed a stunningly complex answer to the mystery.

Plants are largely controlled by hormones and some insects have managed to use this feature to their own advantage. (Gall-making insects use a similar technique to force non-standard growth of leaves, buds and roots.) The hormonal signature of the Ectoedemia larvae was noted to be similar to that of some bacteria, and the bacteria were found to be present in the larvae. When the larvae were dosed with an antibacterial, the leaves failed to make mines, so the bacteria are essential for the green islands to form. It looks like the larvae have formed a symbiotic relationship with the bacteria in order to perform their season-extending trick. The closer you look, the more complex our wildlife appears.

This is a good time of year to look at mosses and lichens: the season's growth has died back to reveal our smaller species and many of them are now fruiting or making spores.

This Cladonia lichen has bright red fruitbodies. Looks to be Cladonia macilenta.

Lycogala terrestre is a slime mould which forms purplish spherical bodies which later split to reveal a bright pink spore-bearing interior:

Just as I was leaving the woodland I spotted a group of Lesser Dungflies spread around various leaves on Bramble: