Tuesday, April 15, 2014

The Plant that turns Lawns Blue

It's the season for slender speedwell Veronica filiformis, a Victorian rockery favourite that first hopped over the garden wall in 1838, but didn't really begin its rampage until the late 1920s. It has been on the run ever since, invading lawns everywhere. The New Atlas of the British and Irish Flora confirms that it is still spreading.


The remarkable thing about this little colonist is that it almost never produces seeds but has spread the length and breadth of the country via vegetative propagation, thanks to its creeping stolons that thread their way through the grass, lawnmowers and the distribution network created by wholesale and retail horticulture that introduced it to gardens throughout the nation in the early years after its introduction from Turkey in 1808.



Once established in lawns, slender speedwell was distributed in lawn turf and then propagated by lawnmowers. Each pass of the mower takes hundreds of cuttings and many of them will quickly root. One plant can soon become a blue carpet.

As with daisies, it thrives in short grass - let the lawn grow a bit and it will struggle to compete. It's our national fetish for well-mown lawns and their establishment from turf that's already infested, rather than growing a lawn from seed, that has ensured its survival and spread.


Monday, April 14, 2014

Red squirrel in the Eden valley


Last week, when I was watching this delightful red squirrel feeding in a sycamore on the banks of the river Eden near Kirkby Stephen in Cumbria, I could see exactly why people find this species so much more attractive than their grey cousins, and also why they were so ruthlessly persecuted back in the 19th. and early 20th. century. 



Aside from their coat colour, magnificent tails and tufted ears, it's the sheer speed and agility of the native species that's particularly striking. In comparison, grey squirrels often look corpulent . Maybe that's more than a little due to the red's spartan diet of seeds, buds and bark, unlike grey's menu which includes more or less anything and everything, especially in urban areas where there's plenty to scavenge from waste bins. 


But in the past it was the red's liking for buds and bark that began its downfall. While I watched this one stripped bark off several branches and it was this kind of behaviour that led to intensive culling in the first half of the 20th. century, at the instigation of estate owners. The Highland Squirrel Club, formed in 1903, succeeded in exterminating 85,000 red squirrels over the next 30 years and that kind of persecution, together with habitat destruction, must have played a role in making the red squirrel population more vulnerable to the spread of their grey counterparts.





Saturday, April 12, 2014

Stonefly


I found this stonefly crawling on the footpath on Wylam bridge across the river Tyne yesterday.


Key identification features of stoneflies are their flattened profile, paired tail filaments and a strong propensity to scuttle along rather than fly.




































Stoneflies, which are important food for fish and birds like dippers and wagtails. They're very sensitive to water pollution so their presence is a reassuring sign of good water quality in the river.

Click here for more on stoneflies.


Gorse Shieldbug

Found this little gorse shieldbug Piezodorus lituratus  on the broom bushes beside the river Tyne at Wylam yesterday.




































From this angle the articulated rostrum, used for puncturing plant stems and sucking out plant juices, is clearly visible, along with the distinctive row of spiracles along the edge of the abdomen.

Click here for pictures of another species, the red-legged shieldbug


Wednesday, April 9, 2014

Close encounters with hares

Thursday's Guardian Country Diary describes close encounters with hares on Chapel fell, at St. John's Chapel in Weardale.














I was leaning over the wall admiring the view (and getting my breath back after a long, steep climb) when this hare appeared from behind a tussock of grass, just twenty metres away, ......


....... and I expected it to turn tail and run, but instead ......



...... it just ran straight towards me, then .... 





.... just sat and stared at me. Then it started to run towards me again, leapt onto the wall just a few feet away, then ambled off across the track, leapt into the far wall then jumped down into that pasture and disappeared again amongst the rushes. I couldn't photograph any of that because it was simply too close to me. Fortunately ..........


...... another hare appeared in more or less the same place ....


....... but a little further away, and repeated the whole performance. Once again it was too close for me to photograph on the wall that I was leaning against ..... but ....


... it stopped on the track to nibble some grasses ... 


...... giving me time to get my wits together, focus as it loped across the track ...



































.......... and photograph it when it leapt onto the far wall.

If I didn't have the photographs, I'd think I was hallucinating. Hares can have that effect on people.


Tuesday, April 8, 2014

Out of an empty sky.....

Thinking back a decade or two, there was a time when I very rarely saw a buzzard on the north eastern side of the Pennines. These days its rare to go out for a day, especially in spring, and not see at least one here. They seem to be commoner than kestrels. That perception might have something to do with the fact that buzzards are so much more vocal, with their mewing cries, than kestrels and so attract attention. A couple of years ago I watched no less than eight buzzards circling over St.John's Chapel in Weardale.

Today we were over on the western side of the Pennines, near Kirkby Stephen in Cumbria, where buzzards have always been more plentiful.



This pair appeared from nowhere just at the moment when the clouds parted and the sun broke through - and as always it was that mewing call that made us look upwards. I could watch the effortless soaring of these birds for hours - they cover such large distances with just a few shallow wing beats.



































They were joined by this tatty-looking individual which had moulted its outer primary feathers, although that didn't seem to have impaired its soaring ability in any way.


Sunday, April 6, 2014

The daughter of the winds




The name anemone, which is derived from Greek, literally means 'the daughter of the winds' and the Roman naturalist Pliny the Elder believed that spring winds were essential to bring anemones into flower. You certainly need a still, windless day to photograph these  delightful spring flowers, that shiver on their slender stalks if there is the slightest breeze. 



Wood anemones are grow very slowly, spreading via creeping rhizomes, so woodlands with large patches of this flower are likely to be very old. It sets few viable seeds and spreads at a rate of about six feet in one hundred years, according to Richard Mabey in his Flora Britannica. It's plants like this that highlight the foolishness of the government's proposed practice of allowing developers to 'offset' destruction of  old-established woodlands by planting new ones on open fields.  Assuming it was possible, it would take centuries to replicate the drifts of wood anemones that are one of the defining features of ancient woodlands.


This seems to have been an exceptionally good spring for wood anemone, with some wonderful displays in woodlands in Weardale and Teesdale.


Saturday, April 5, 2014

Townhall clock


Moschatel Adoxa moschatellina  is one of the most easily-missed woodland spring flowers due to its small size and green flowers, but it's worth taking a close look at its inflorescence because it's really rather remarkable.


The inflorescence, in a two inch-tall stalk, is made up of five small flowers. Four face outwards like the faces of a townhall clock, giving the plant its alternative common name. Each of these has five petals and ten stamens. 

The fifth flower points upwards and this one has four petals and eight stamens. 




There's nothing else quite like it in the British flora. 


Friday, April 4, 2014

Here today, gone tomorrow: leafy liverwort spore capsules

Leafy liverwort leaves are only one cell thick and have no means of controlling water loss, so these plants are always confined to permanently wet places. This is Lophocolea bidentata


The tiny, delicate plants spend most of their year in the vegetative state but in late winter they enter their reproductive phase and produce microscopically small egg cells inside flask-shaped structures called archegonia hidden amongst the leaves, and also minute containers of male sex cells called antherozoids. 

The antherozoids swim in the surface film of water on the leaves, frantically heading for the archegonia that release a chemical attractant. A surface film of water is essential for successful sexual reproduction in these plants. When the sex cells fuse a spore capsule forms, filled with minute spores, and when it's ripe this elongates on a two inch-long stalk, often overnight............and ......



































.............. that's what these are - a forest of ripe Lophocolea spore capsules, like little black beads, already beginning to burst and shed their spores (the white fuzzy structures are burst spore capsules). In another day they will all have shed their spores and withered away, their reproductive phase over for another year.

Although their reproductive season is short livrworts been around for about half a billion years, surviving five great mass extinctions that have wiped out many other life forms. Fragile plants, but durable within the great evolutionary time scale.

Wednesday, March 26, 2014

Toothwort and toothache: a botanical old wive's tale.

Thursday's Guardian Country Diary concerns toothwort Lathraea squamaria, the parasitic flowering plant that depends entirely on hazel trees for its nutrition, since it is a plant without chlorophyll.
















There is no hint of the plant's presence until March, when its scaly flowering shoots, which look quite reptilian and menacing, erupt through the soil.


















They're attached to hazel roots and some, like those in the picture above, can appear in grass some distance away from the trees, revealing how far hazel roots extend underground. 



















After a brief flowering period, during which they attract bumblebee pollinators, the flowering  shoots soon set seeds and then by early summer they wither away.



































Almost every wild flower book that I've ever read explains that the plant's common name arose from the appearance of  its flowers, which resemble rows of discoloured teeth, and then go on to suggest that it acquired its name via the Doctrine of Signatures. This fanciful notion, which dates back to Roman times and the physician Dioscorides, claimed that plants to look like a part of the human body will cure that organ's ailments. So with it's toothy appearance, toothwort must surely be a cure for toothache....... 



































...... but there seems to be no evidence that anyone ever tried to use the plant in that capacity. In their scholarly work Medicinal Plants in Folk Tradition (2004) David E.Allen and Gabrielle Hatfield could only find one slight reference, in Gerard's Herbal, to a medicinal use for the plant and that was to treat lung complaints. It seems that the use of toothwort in folk medicine for dental self-medication is one of those plausible myths that never dies but is endlessly repeated.

The Doctrine of Signatures owes much to the German botanist Phillipus Aureolus Theophrastus Bombastus von Hohenheim (1493-1541) who, unsurprisingly, is best known by his shortened, Latinised name: Paracelsus. He refined the concept and it was later taken to absurd lengths by the English herbalist William Coles (1626-62), whose book Adam in Eden, or Nature's Paradise, woven together religion and botany, claiming that God created plants to look like body organs in order to signify their medicinal virtues to humans, extending the Doctrine far beyond the limits of credulity for all but the most devout.