Thursday 21 November 2013

Firethorn

Red and yellow bushes of Firethorn
beside the Bell Brook, Byfield.
21 November, 2013
Firethorn is a particularly well-named shrub. I have a vigorous specimen in my back garden and I always don gloves when pruning time comes around. The plant usually grown is Pyracantha coccinea, a native of southern Europe where I have found it from time to time on stony hillsides. Though not native to Britain it is well naturalised in many places, probably through bird-sown seed. 


Around Byfield it is a feature of many gardens, with both yellow and, more commonly,  red-fruited specimens planted. The plants are usually clipped but, when allowed to assume their natural form, they are rather pendulous. Both yellow and red tumble down beside the Bell Brook in this graceful manner.

The fruits are still rather firm as I write but as they soften they will be eagerly sought after by birds and the lucky gardener may receive visits by Waxwings in midwinter. The "berries" may look rather like those of Holly but the plants are unrelated. Firethorn is a member of the Rose family and thus related to Rowans and Cotoneasters, whose fruit not only look similar but are structurally near-identical. In a close-up photograph the fruit look almost like apples, to which, again, they are related.
Fruit of Pyracantha coccinea.
Byfield, 21 November, 2013


The plants are of interest too to the entomologist. Not only are the flowers attractive to bees but a micro-moth, the Firethorn Leaf Miner, makes use of the leaves. It seems to have been unknown in Britain before 1989 but is now very widespread; here in Byfield it affect many specimens. 




It forms an elongated blister-like mine down the midrib of the leaf, more clearly seen in this close-up, where the frass (droppings) show up as amber specks. The leaves may be a little disfigured but the plants seems to be otherwise unaffected.


Leaf mine caused by the Firethorn Leaf Miner Moth
Phyllonorycter leucographella.
Byfield, 21 November, 2013




Monday 18 November 2013

In search of Black Puddings

Northamptonshire has a limited fern flora but here and there, where the soil is reasonably well drained and not too heavy, substantial beds of bracken are to be found. One such site is near the summit of Solden Hill, to the south west of Byfield. I set out earlier today in the hope of finding some bracken plants galled by the tiny fly Dasineura pteridis. The larva of this insect forms tiny sausage-shaped galls on the edge of bracken fronds which, from their shape and colour, are called 'Little Black Puddings'.

A fine mist caused droplets of moisture to form on my eyebrows as I strode out and the visibility was down to half a mile or so as I looked out towards the west.

Looking west from Byfield on a misty
morning, 18 November, 2013


As I left the village my attention was caught by a large-ish Crab Apple (I use the term loosely - see my blog for 10 December, 2012) well laden with fruit. As they ripen further they will soften and fall, to provide valuable food for birds, especially species of thrush.
Crab Apple heavy with fruit.
Byfield, 18 November, 2013
The tree will almost certainly have sprung from the seeds in an apple core thrown to the side of the road, and therefore will not be a true Crab Apple. 

Crab Apple showing the typical leaf fold caused
by the Rowan Slender Moth
Byfield, 18 November, 2013


Dozens, if not hundreds, of the leaves showed mines formed by a tiny moth, the Rowan Slender (Parornix scoticella). As its name suggests it is frequent on the leaves of rowan but apple trees (which are closely related to rowan) are equally acceptable. Despite being a common and widespread insect it is the first time I've recorded it from the Byfield area, so I was quite pleased. Leaf mines and galls are hardly exciting but, by revealing what insects are around, it enables a better understanding of the ecology of a particular habitat. 




Coltsfoot plants were common along the roadside, with some of the leaves bearing a mine which opened up into a large blotch. This shape is diagnostic for Phytomyza tussilaginis, an agromyzid fly for which no common name exists. The actual fly is not often observed and the mine created by the larva is the best clue to its presence.


Coltsfoot leaf mined by Phytomyza tussilaginis.
Solden Hill, nr Byfield. 18 November, 2013







  
The murky conditions persisted as I pressed on but, murky or not, several plants were in bloom. None was receiving an insect visitor of course but, given a sunny day in the next week or so, a late hoverfly could make a call.  White Campion (Silene alba) was bearing a few flowers and nearby was a hybrid White Campion x Pink Campion (Silene alba x Silene dioica) although only the one parent could be found.
White Campion


Hybrid White x Pink Campion











Yarrow (Achillea millefolium) was present in some profusion, as was White Dead-nettle (Lamium album) but only a couple of bedraggled Common Ragwort plants were in bloom. One plant of Hedge Woundwort (Stachys sylvatica) was also doing its best, with the drizzle-covered leaves making it look like its garden relative, Lamb's Ear (Stachys  byzantina).
Hedge Woundwort, Stachys sylvaticaSolden Hill. 18 November, 2013






Common Ragwort
Solden Hill, 18 November, 2013


Yarrow. Solden Hill, 18 November, 2013















White Dead-nettle. Solden Hill
18 November, 2013




By this time I too was bedraggled, but I had reached my destination - several large clumps of Bracken. I spent several minutes carefully examining the fronds and found - not a sausage. Certainly not a Little Black Pudding. I'll try again in a few months, this time choosing a bright and warm sunny day.

Friday 15 November 2013

In praise of ivy.

Let's face it, ivy can be a nuisance. When we moved into our current house one wall was clad with it and had got completely out of hand. To remove it was beyond me, given the height it had reached, and I had it professionally removed - not a cheap job. From time to time in recent years, trees top-heavy with ivy have crashed down across the A361, blocking it for several hours. Lichenologists and bryologists hate it for the way in which it smothers tree trunks, destroying the surface as a habitat for lichens and mosses respectively. And yet...

Ivy belongs to a plant family called the Araliaceae. My copy of "The Families of Flowering Plants" by John Hutchinson, published in 1959, suggests the family has 250-260 members; more recent floras put the number at around 1500 species. This is partly because studies in tropical rain forests (it is largely a tropical and subtropical family) have led to the discovery of many new species. But it also reflects the fact that the parameters for defining the family are far from clear and it is likely that, as the genetics of the family are unravelled, the figure could change drastically again.

Ivy, our sole member of the family, is Hedera helix. I assume that this suggests that the plant stems form a helix as they grow upwards in the manner of runner beans, but I have rarely seen them adopt a helical habit. The species is found throughout Britain and from Norway across to Iran but is absent from Russia.
Ivy scrambling across the woodland floor.
Byfield Pocket Park, 15 November, 2013


So, what can be said in its favour? It is reasonably hardy though not bone-hardy; it will flourish in dry and gloomy conditions where little else can survive and it has some attractive forms with bright yellow variations of the leaves. So much for its gardening merits. What of relationship with other wildlife? A song dating from 1943 called Mairzy Dotes tells us that:

                        Mares eat oats and does eat oats 
                        And little lambs eat ivy.

In fact the plant is occasionally browsed by deer and cattle and has been used as emergency fodder over many centuries. Only one insect (Dasineura keifferi) forms galls on the developing flower buds and although caterpillars of the Holly Blue butterfly will feed on the foliage, as far as I am aware not one insect mines the leaves. For such a widespread plant this is a remarkably low usage. However, that is not the whole story. 
A calliphorid fly feeding on ivy nectar.
Byfield Pocket Park. 15 November, 2013

Ivy begins to flower in mid August and at the time of writing is still in flower in our village pocket park. The flowers are dioecious, that is, there are separate male and female flowers. In the third photograph the male flowers can be clearly seen beside the now-fruiting females. These flowers provide a copious supply of nectar and are besieged by many insects including hover flies, bees and even today (15 November) wasps were gorging on this energy-rich liquid. 


When Shelley, in his poem "Poet's Dream", wrote of "The yellow bees in the ivy bloom" * he was writing of something which must have been going on for, probably, millions of years. The flowers eventually lead to fruit which slowly ripen to be available to birds as the year draws to a close. Even now, with some branches bearing flowers, others bear almost-ripe berries. It is a clever strategy because, in late winter, hungry birds will gorge on these fruit, ensuring widespread dispersal of the seeds via their droppings.

Ivy with ripening fruit. Byfield Pocket Park
15 November, 2013
In my first photograph, showing ivy sprawling across a woodland floor, the leaves are of the classic shape as shown on millions of Christmas cards. However, it will be seen that the flowering/fruiting branches bear leaves of quite a different shape, being of a simple, more or less elliptic shape and far glossier than the palmate ones.
 




So, a pest or an asset to the countryside? As with so many questions of this type, it is a matter of opinion but during recent decades ivy seems, over many areas, to be getting out of control. Perhaps we should return to using it as fodder.




* In this year of Benjamin Britten's birth centenary I should mention that he set this poem beautifully for tenor voice in his "Nocturne", opus 60) 

Wednesday 13 November 2013

Mostly mosses

A chill must have gripped my readers' hearts when, in my last blog, I mentioned that I was considering checking out the mosses and liverworts of the Byfield area. But putting such thoughts aside I sallied forth a couple of days ago to renew my contact with these much-neglected plants.
Blue Roundhead, Stropharia caerulea?
Flower bed in Byfield. 8 November, 2013

In fact, the first organism to catch my attention as I passed the village hall was not a moss or a liverwort. Not a plant at all but a fungus. With a cap only 20 mm across it would have been easy to overlook it but its pale blue colour, glistening with slime made it stand out among some dark wood chippings. I am not a mycologist and therefore cannot be confident in my identification but, if it is not Blue Roundhead (Stropharia caerulea), it is certainly one of its close relatives.

I pressed on and after an hour or so had recorded half a dozen mosses and liverworts, all very common. On a fence post in the Pocket Park was Common Pincushion Moss (Dicranoweisia cirrata). 


Common Pincushion, Dicranoweisia cirrata. Byfield Pocket Park
8 November, 2013

Each moss species tends to favour a particular substrate - acid rock, alkaline rock, tree bark, bare soil and so on. A weathering fence post such as the one shown is a typical habitat for Common Pincushion.

Adjacent to the Pocket Park is a burial ground. Large areas of the "turf" were composed more of moss than grass, the culprit being Springy Turf-moss, Rhytiadelphus squarrosus. It is indeed very springy and pleasant to walk on - but try telling that to a gardener whose lawns are infested with it. It is a beautiful moss too under a microscope, a feature to which my photograph fails to do justice.


Springy Turf-moss, Rhytiadelphus squarrosus
Byfield burial ground, 8 November, 2013


My final call was the churchyard. (Come to think of it, its the final call for many of us.) Again, very commonplace mosses were present until, on a damp shady section of wall I saw something rather different. "Ah," I said to myself. "That looks like a Pouncewort." (Don't tell porkies. Admit you didn't have a clue!) O.K. other than recognising it as a liverwort, I really didn't know.  Once home, a bit of investigation with Watson (that's E.V.Watson*, not Sherlock Holmes' sidekick) I keyed it out as Lejeunea cavifolia. Latin names are often a bit of a mouthful but the common name is Micheli's Least Pouncewort. For once the Latin name seems simpler. 

Micheli's Least Pouncewort, Lejeunea cavifolia.
On wall, Byfield churchyard. 8, November, 2013




This liverwort is largely confined in Britain to Wales and the west country. It is only known from a handful of sites in Northamptonshire so I was smugly satisfied with my find. 





Once home, I paid attention to the porch over our own front door. It is constructed using a fissile limestone akin to Collyweston Slate and is a congenial home for many mosses. The most abundant of these proved to be Grey-cushioned Grimmia, Grimmia pulvinata, instantly recognisable from the way its setae (fruiting capsules) are curved over to bury their heads among the leaves. Long, whiskery leaf tips give it a greyish appearance.






I finally strolled around my back garden
Overhanging porch with a rich growth of mosses.
Byfield, 8 November, 2013
in search of Common Pocket-moss. It is unusual in appearance, looking like a minute fern. Very common, I have found it in many gardens growing on damp, bare soil and again I was not to be disappointed. The area in which I found it is constantly disturbed by weeding, hoeing and so on. It looks delicate but it is a tough little plant and survives against the odds.



Common Pocket-moss Fissidens taxifolius in my own garden
8 November, 2013



  



POSTSCRIPT 

I was uneasy about the 'Pouncewort' so I sent a sample to Rachel Carter, the county bryophyte recorder. She identified it as a considerably commoner but close relative, Porella platyphylla, known as Wall Scalewort. 

* E.V.Watson, "British Mosses and Liverworts". First published in 1955 it is, with numerous revised editions, still perhaps the best introductory book on the subject.


Wednesday 6 November 2013

Five hundred - and counting

On 3 November the total number of arthropods (insects, woodlice, centipedes, etc) recorded from Byfield Pocket Park passed the 500 mark and has now reached 506. The five hundredth species was a common beetle which I should have found long ago. Aphodius contaminatus is a rather small (about 5 mm) Dung Beetle, related to - but far less charismatic than - the scarab beetles of Egyptian fame, being a dull brown with darker markings. Nevertheless it is, like its Egyptian cousins, often found investigating dung, with rabbit droppings arousing interest.

Aphodius contaminatus found in Byfield Pocket Park
4 November, 2013
This beetle presented few difficulties but I also took a leaf beetle for which dissection of the genitalia will be required for identification. As the specimen is barely 3 millimetres long I fear it will remain unidentified.


At this time of the year it can be a challenge finding insects, although leaf litter can be productive. Insects may not be abundant but small linyphiid spiders - "money spiders" as they are popularly known - can be surprisingly common, so the total for the pocket park should continue to creep upwards. Failing that I'll blow the dust off my copy of E.V.Watson's "British Mosses and Liverworts" and see what this area has to offer.

It is obvious even to the naked eye that mosses can be very attractive; under a microscope they are often beautiful and their study is, I find, very rewarding. From time to time small creatures known as tardigrades will be found in the moss. These extraordinary animals can be frozen to near absolute zero temperatures and survive. Similarly they can be freeze-dried, boiled, subjected to theoretically lethal doses of radiation, - and still survive. It is not surprising that they are the subject of intense interest in university laboratories around the globe.