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.

Monday, March 24, 2014

White Violets

We found this large patch of white sweet violets, with more than 100 blooms, beside the disused railway line near Cotherstone in Teesdale at the weekend.

Sweet violet Viola odorata is the earliest of the violets to bloom and also the species that most often produces white-flowered variants. It spreads via stolons and this patch, which was more than a metre across, must be quite old. Although sweet violet is a native species it's often hard to tell whether plants are genuinely wild or are descendants of plants that have been planted in gardens and have then escaped back into the wild after being dumped with garden waste.  This patch is difficult to reach, under a very prickly hawthorn, and grows amongst stinging nettles which must hide it in summer.

Wednesday, March 19, 2014

The Last Day of Winter in Teesdale

Spent the last day of winter walking beside the river Tees through woodland downstream of Egglestone Abbey in Teesdale. The pace of spring is picking up!

Sunlight streaming through hart's tongue fern fronds, revealing the herringbone pattern of sori underneath.

Ivy berries ripening fast - a fine crop, food for many birds.

Wood anemones coming into flower.

Male cones of yew releasing pollen

Golden saxifrage in full bloom.

Saturday, March 15, 2014

The Go-Between

Tree bumblebees collecting nectar from sallow blossom this morning, beside the river Tyne at Wylam in Northumberland. They seem to be hardier than other bumblebee species, foraging despite the fact that it was cold and very windy.

Most trees that produce catkins in spring are wind pollinated but sallow relies on insect pollinators (and occasionally, perhaps, birds like blue tits that have a liking for nectar). Both male and female catkins of sallow produce nectar to attract the first bumblebees, flies and butterflies of spring. There are separate male and female sallow trees so these insect go-betweens are essential for successful seed set. The catkin above is a female and ...

..........this one is a male sallow, producing nectar and pollen. The bee has just withdrawn its proboscis from the flower (it's the brown tube with the knee-bend) and it has yet to withdraw it between the two protective sheaths that also give it rigidity: you can see the sheaths pointing upwards in a V-shape (double click image for a larger, clearer view).

Wednesday, March 12, 2014

Spurge laurel - made for the shade

Thursday's Guardian Country Diary is about a lone spurge laurel Daphne laureola plant, that I first found 35 years ago and is still thriving, partially hidden in the shade of a holly and hawthorn hedge at Wolsingham in Weardale. 

It's an easy-to-overlook plant until early March, when it produces these tight clusters of lime green flowers. The flowers, whose nectaries are at the bottom of the floral tube, attract long-tongued bee pollinators during the day but, like all Daphne species, they're scented. Their fragrance is weak during the day but much stronger at dusk, when they attract moth pollinators.

It's a very uncommon plant hereabouts. This year the shrub narrowly escaped serious damage when a tractor with a hedge cutter was used to trim the hedge. It was saved by the fact that it's a shade-loving plant and was so well woven into the gloom at the bottom of the hedge that the cutter could only reach a few of the tips of its twigs. I've rescued those and managed to root a couple, and if I can grow it in the garden next year I hope to take a closer look at the kinds of moths that are attracted to its nocturnal fragrance.

Beautiful beetles with unappealing habits

Two more photos from the past, found at the back of a cupboard and taken about 20 years ago.

This beetle, which turned up in our garden, is Oieceoptoma thoracicum, whose mottled exoskeleton has the appearance of shimmering silk. Apparently it feeds on insects found in dung and dead animals.

I found this very fine sexton beetle Nicrophorus investigator on the sand dunes at Embleton on the Northumberland coast. Sexton beetles bury corpses of dead animals by excavating the soil from under their bodies, then lay their eggs in the corpse. The females stay with the corpse and feed on it until the grubs hatch, then she feeds them with regurgitated food until they're large enough to tuck into thje corpse unaided. Nice.

Monday, March 10, 2014

Snowdrop Micromoth

I found this tiny micromoth yesterday when it was siphoning nectar from snowdrop flowers. Thanks to Stewart at From the Notebook for identifying this moth for me as Ysolopha ustella.

It seemed to be very proficient at slipping its long proboscis in between the petals to reach the nectar, so it might be a snowdrop specialist.

 In the second picture you can see that it has a scattering of golden scales when the sunlight strikes its wings.

Sunday, March 9, 2014

Green common lizard

Another old photograph found in the back of a cupboard.

Taken about 20 years ago in Hamsterley Forest and showing an unusual emerald green variant of the viviparous lizard. 

I'm not sure whether is was a young one in the process of acquiring more typical colours or whether it was part of a population whose colours were better adapted to a forest habitat. I've never seen another green one.

Those that live on open moorland nearby are usually coloured with shades of brown, grey and buff. Click here for a photo of a more typical local example.

Friday, March 7, 2014

Mass jellyfish stranding on the Northumberland coast

More old pictures from the mid-1990s. These are from Embleton beach in Northumberland and show the most spectacular mass jellyfish stranding that I've ever encountered.

Thousands of jellyfish, mostly the Lion's mane Cyanea capillata but also C.lamarckii and moon jellyfish Aurelia aurita, as far as the eye could see .....

.... in both directions. The largest was about the size of a dinner plate.

Wednesday, March 5, 2014

Melanic magpie moth caterpillar

More photos from the 1990s found in the back of a cupboard.

Every few years our garden gooseberry bushes are infested with magpie moth caterpillars. They're hard to miss, with this gaudy black, white and red colour scheme which is a form of warning colouration (aposematism), warning birds that they are foul tasting: the theory is that any bird eating one would remember not to eat these colourful but distasteful caterpillars again.

One infestation included this all-black melanic mutant magpie moth caterpillar. 

Industrial melanism, where mutant black forms of the pale grey peppered moth Biston betularia appeared and rapidly increased in frequency, is one of the classic textbook examples of natural selection in action, based in crypsis. In that case the melanic form provided better camouflage against sooty tree trunks in industrial cites, was less frequently predated by birds than the pale grey form and so rapidly increased in frequency. When air quality improved in cities and the soot disappeared from tree trunks the melanic form became more conspicuous and vulnerable and the better camouflaged pale form increased in frequency again.

With this melanic magpie moth caterpillar the selection pressure is quite different because this insect larva benefits from being conspicuous and warning birds of its unpalatability. Losing its bright colours ought to be a distinct disadvantage. 

Maybe that's why, in the 20 years since I took this photograph, I've never seem another melanic magpie moth caterpillar on our gooseberry bushes.

Sunday, March 2, 2014


I found this photo, which I had forgotten all about, when I was clearing out an old cupboard. I can't remember exactly when it was taken, other than that it was in spring, probably in the early 1990s. 

It was taken at Harperley Hall in Co. Durham, which at that time was a training centre for police horses. These birds love to forage for insects in dung heaps, so the sweepings from the stables would have been a magnet for a passing hoopoe. 

I was tipped off that it had been spotted by residents but at that time didn't have any decent photographic equipment and the camera that I had was loaded with colour print film. When I arrived it was sunbathing in the middle of the track, unperturbed by the approach of a car - but as soon as I stopped and got out it was off.

Sadly there are no police horses at Harperley any more, but I hope that one day another of these exotic birds will drop in locally, wafted along with the swallows by warm spring southerlies. Maybe this spring. I'll be ready this time.......