Thursday, June 30, 2011

Rhinocerus beetle

We found this newly emerged specimen of a Rhinocerus beetle Sinodendron cylindricum on an old beech log in Allen Banks. Unfortunately the rotten wood fragments clinging to its head, where it forced its way out of the wood that it has fed on as a grub, partially concealed the 'horn' in the centre of its head and it scuttled away before I could brush them off for a better photo.

It has spikes protruding from either side of its thorax, in addition to the horn on its head.

Wednesday, June 29, 2011

Plants to Stuff a Mattress with.....

In the past - as their name suggests - some bedstraw species have been used for stuffing mattresses because they have pliable stems and make fragrant hay when dried. You would need to spend quite a long time collecting enough of this little ground-hugging species - heath bedstraw Galium saxatile  - to stuff a pillow, let alone a mattress. Up here in the North East heath bedstraw is quite common on dry, acid soils - this specimen was growing on bare ground in a felled pine plantation in the Derwent valley.

All bedstraws have stems with a square cross-section and tiny flowers in the form of a simple cross. This one is - appropriately - crosswort Cruciata laevipes (which was known as Galium cruciata when I was a botany student).

Crosswort has a long flowering period, from spring into summer and ..

... is robust enough to compete with grasses, often forming large stands on grass verges

Woodruff Galium odoratum has a particularly sweet scent of new-mown hay when it's dried (when it also turns black) and, around here at least, is the commonest woodland bedstraw. The other common feature of this family is that they all have their leaves arranged in whorls around the stem - and the leaves are especially large in this species.

The commonest bedstraw - cleavers aka goosegrass aka sticky Jack aka Galium aparine - is a persistent weed whose hooked hairs stick it to clothing, making it a favourite weapon for kids who like to throw handfuls of the plant at each other (at least they did in my day, maybe they do it electronically on a Playstation today). I've found this a handy plant for clearing my pond of duckweed, by dragging handfuls across the surface of the pond - it works a treat. I thought that this was my discovery but apparently handfuls of the plant have long been used as a crude filter for liquids - the Greek botanist Dioscorides (40-90 AD) got there before me and described how it could be used for straining milk.
The stem, seen in cross-section under the microscope, is also surprisingly beautiful.
Hedge bedstraw Galium mollugo, is another robust species....
.... that grows well over 50cm. tall and enlivens grassy places with masses of tiny flowers in late June and early July.

And finally, lady's bedstraw Galium verum which contains large amounts of coumarin and so has a powerful scent of new-mown hay when dried. The flowers have a honey-like scent. There have been attempts to cultivate this plant for the red dye produced by its roots, as a substitute for madder (which is also in the bedstraw family) and there are accounts of its flowers being used as an early source of yellow dye for colouring Cheshire cheese, adding sweetness to the flavour, although annatto from the tropical plant Bixa orellana replaced it. Apparent, the bones of pigs and chickens fed on lady's bedstraw turn red, which could add an interesting splash of colour to the Sunday roast.

Although bedstraws were used for stuffing mattresses (myth has it that lady's bedstraw, formerly known as Our Lady's Bedstraw, was used to stuff the Virgin Mary's bed, and Henry VIII is said to have enjoyed sleeping on a hay-filled mattress) it has been suggested that the 'straw' part of the name is a corruption of the word 'strow' and that the commonest use of this fragrant plant was as a strewing herb on floors. John Gerard describes how woodruff "being made up into garlandes and bundles, hanging up in houses in the heat of summer, doth very well attemper the aire, coole and make fresh the place, to the delight and comfort of such as are therein". More recently, in Victorian and Edwardian times, lady's laid the dried plant in the bottom of their drawers, to impart a sweet odour to stored clothes and to deter moths.

Saturday, June 25, 2011

Gruesome Greenfly Pictures...

If your garden is as plagued by greenfly as mine is, then this will be a welcome sight - a hoverfly larva tucking into an aphid. It's interesting to watch one of these voracious larvae crawl into a group of aphids. Once the aphids are attacked they emit alarm pheromones and the whole colony instantly becomes restless and begins to drop off the plant in a desperate attempt to escape........ but some are not quick enough....

The hoverfly larvae swallow the aphids tail-first....

... or head-first; they are not choosy. Hoverflies are assets in any garden. Many are pollen feeders, so a good supply of pollen-rich flowers (the daisy family is always a good bet) will ensure that they breed in a garden and produce plenty of these useful predators.

Recently the alarm pheromone that aphids produce and makes them drop off plants when they are threatened has been genetically engineered into wheat crop plants, in an attempt to protect the plants from aphid attack.

Friday, June 24, 2011

Wolves of the Water Surface

On sunny days wasps often land on the patches of duckweed on our pond, to drink from the surface - and sometimes they fall in and become trapped in the surface film. Within a few seconds the vibrations from their frantic struggles are propagated over the water surface and detected by the pond skaters that patrol the pond. Soon the first arrives and punctures its prey with its needle-sharp proboscis. In its eagerness to feed it has put its foot through the wing of the drwning wasp.

Soon another pond skater arrives ...

.... and another.

They home in like a pack of wolves ....

... until the doomed wasp is completely surrounded...

... and the feeding frenzy begins.

Vegetable Vampires 3: Hay rattle

Hay rattle Rhinanthus minor is the quintessential hay meadow wild flower that’s not only decorative but also popular with the bumblebees. It isn’t easy for an annual plant like this to compete with all the other plant species in a meadow but like other hemiparasitic flowering plants its solution to the problem is to dispense with an extensive root system of its own and, instead, plug itself directly into the roots of the surrounding grasses. This has a double benefit, providing it with water and mineral nutrients and suppressing the grown of tall host grasses around it.

In recent years conservation biologists have exploited hay rattle’s grass-suppressing properties in attempts to improve species diversity of degraded grasslands. It’s an easy plant to introduce if you want to turn your garden lawn into a miniature ‘hay meadow’, provided that you make sure that you rake the hay rattle seeds into the soil around the base of the grasses in autumn. It needs prolonged winter chill to break the dormancy of the seeds that tend to germinate in early April. Once the plant has flowered and set seed once it often tends to form a self-sustaining population.

Hay rattle seed capsules are enclosed with leaf bracts and the whole assemblage becomes dry and brittle has the seeds ripen, so the plant rattles in the wind. It’s said that the traditional time to cut a hay meadow was when the yellow rattle begins to rattle.

Tuesday, June 21, 2011

Here's a sight you don't see very often....

If you happen to be travelling out of Durham along the dual carriageway towards Darlington, pull into the lay-by and take a look at the fields on your left as you travel down from what used to be called the Cock 'o the North towards Croxdale. You still sometimes see arable fields with fine displays of poppies when their seeds are brought to the surface by the plough, but it's rare to see displays like this.

This land was formerly sown with cereals and oilseed rape but was bought by the Woodland Trust a few years ago. Eventually it will all be replanted as public-access woodland, to join up with the fragments of ancient woodland you can see in the distance in these photographs.

In the meantime some of it it has been sown with the kinds of arable field wild flowers that were a common sight before the days of intensive farming - corn poppy, corn chamomile, corncockle, cornflower.

It's a wonderful sight - well worth stopping to have a wander through if you happen to be passing - there's a gate in the fence near the lay-by. I've uploaded these photographs larger than usual - so it you double-click on the images you'll get a better impression of the spectacle.

Monday, June 20, 2011

How to Make your Urine Smell of Violets

They're fiddly to pick - I guess it would take most of the day to pick enough for a jar of jam - but sun-warmed wild strawberries Fragaria vesca have a wonderful flavour and aroma that's superior to the taste of most chiller-cabinet cultivated strawberries from the supermarket. According to the herbalist John Gerard, writing in 1597, ripe strawberries "quench thirst, and take away, if they be often used, the rednesse and heate of the face" - just the thing, then, if you're baking in the sun watching the tennis at Wimbledon. On the other hand, if it's raining, he also recommended water distilled from the plant mixed with white wine for "reviving the spirits, and making the heart merry" which I suspect had more to do with the wine than with the plant. Writing nearly 180 years later, the botanist and physician William Withering was clearly a strawberry devotee: "The berries either eaten alone, or with sugar, or with milk, are universally esteemed a most delicious fruit. They are grateful, cooling, subacid, juicy, and have a delightful smell. Taken in large quantities they seldom disagree. They promote perspiration, impart a violet smell to the urine, and dissolve the tartarous incrustacions of the teeth." The British native wild strawberry played no part in the parentage of the cultivated strawberry - which is a hybrid of North and South American species that you can read about here - and by the time that he wrote this, in 1776, Withering may well have been eating the much larger fruits of the New World species, which by then had become popular.

Sunday, June 19, 2011

Three-headed Monster

We found this three-headed corn poppy in Teesdale this morning. Sometimes abnormalities like this can be caused by herbicide sprays but, since there were other perfectly normal flower stems on the same plant, I think this was simply a chance developmental aberration. The flower stem is flattened like a plank - fasciated in botanical parlance - and this sometimes happens when growing points that would normally develop into separate shoots become joined together. There can be a variety of causes, including physical damage by an insect or pathogen, infection by the bacterium Rhodococcus (Corynebacterium) fascians, environmental shock or a genetic cause. There are other examples of fasciation here and here.

Here's a normal one...

Saturday, June 18, 2011


We were standing on Union Quay in North Shields this afternoon (after an excellent fish and chip lunch in the Waterfront), watching a ship move off from its mooring on the quayside. The ship's bow-thrusters churned up the water and several small, silvery fish came floating to the surface. Almost instantly, seemingly from nowhere, terns arrived .....

....spotted the fish ....

..... hovered for a second or two ...

... rolled into a dive ....

.... splashed down (pity this wasn't sharper)

... and made off with the spoils.

Friday, June 17, 2011

Honeysuckle Sawfly, Zaraea fasciata

There I was, sitting in the garden, enjoying the sun and photographing the flowers, when this portly hymenopteran buzzed past my ear and crash-landed on a lady's mantle plant. It's the honeysuckle sawfly Zaraea fasciata (formely known as Abia fasciata) - and that makes sense because our garden hedge is full of flowering honeysuckle at the moment. Its larvae feed on honeysuckle foliage. It only settled for a few seconds and then I lost sight of it, but you can find a much better photograph of this insect at Pete Smith's Focus on Wildlife blog. Now I need to find the larvae on the honeysuckle. This isn't an insect I've seen in County Durham before.

It belongs to a family of sawflies called the Cimbicidae, or club-horned sawflies, that have clubbed antennae. The only other photo I managed to take - with a shift in focus - shows these quite nicely.

There are some more sawfly-related posts here

Thursday, June 16, 2011

Vegetable Vampires 2: Lousewort

Lousewort Pedicularis sylvatica is one of several members of the foxglove family (Scrophulariaceae) that have evolved to become hemiparasites, attaching themselves to the roots of surrounding plants and siphoning off their water and dissolved mineral supply.  Lousewort leaves are convoluted and quite small in comparison with the flowers, which sit inside an inflated calyx that later encloses the seed capsule.

I've seen several suggestions concerning the origin of the name 'lousewort' but one plausible explanation is that it sometimes tends to grow in seasonally wet pastures where there's a high incidence of parasites that infest grazing animals. William Withering, the 18th. century physician and botanist, issued stern advice about the dangers of this plant to livestock. Writing in his Botanical Arrangement, published in 1776, he warned "If the healthiest flock of sheep are fed on it, they become scabby and scurfy in a short time; the wool gets loose, and they will be over-run with vermin". 

Marsh lousewort P. palustris, sometimes known as red rattle, grows in much wetter, permanently boggy sites. Common lousewort is a ground-hugging plant but marsh lousewort sometimes grows to 50cm. or more in height. William Withering also had a low opinion of this plant, commenting that "This is an unwelcome guest in meadows, being very disagreeable to cattle".
For more hemiparasites, click here

Tuesday, June 14, 2011

Carnivorous Plants 1: Butterwort

If every there was a Jekyll-and-Hyde of the plant kingdom, this is surely it. At this time of year common butterwort Pinguicula vulgaris produces delightful little violet flowers that attract pollinating insects that ensure that it sets seed, while at the same time catching and digesting small insects on that rosette of sickly yellowish-green leaves down at soil level.

These plants thrive on the permanently boggy conditions on the old lead mine ore-washing floors at Middlehope Burn in Weardale. There's very little nitrogen in the ground but the small insects that they digest make up for that. The surface of the leaf is covered in glistening, stalked glands producing mucilage that glues the insect down, then tiny glands embedded in the leaf surface release diestive enzymes that convert it into nutritious soup. The rolled edges of the leaves keep the pool of digestive enzymes in place. To see the capture and digestive glands of another, more exotic butterwort species in more detail, click here. The glands release protein-digesting enzymes that curdle milk and butterwort leaves were once used in the first steps in making butter - hopefully making sure that there were no flies stuck to the leaf first!

Butterwort keeps its welcoming flowers and deadly digestive equipment well separated via a tall flower stalk...

... and the precious nectar, there to attract small bee pollinators equipped with a suitably long proboscis, lies inside that nectar spur that you can see at the back of the flower - protected by a forest of fine hairs that prevent small, non-pollinating insects from crawling in and stealing it.

Monday, June 13, 2011

Vegetable Vampires 1: Common Cow-wheat

Backstone Bank wood near Wolsingham in Weardale has an interesting ground flora - one factor that qualifies it for SSSI status - and it includes this attractive little plant that blooms amongst the bilberry around the western edge of the wood. This is common cow-wheat Melampyrum pratense and although it looks harmless enough it's a partial parasite (hemiparasite) on the roots of bilberry. Its green leaves carry out photosynthesis and produce sugars but its roots invade those of the bilberry, siphoning off water and mineral nutrients.
Specialist hemiparasites like this thrive in soils with low fertility where there is intense competition for essential but scarce minerals, like nitrogen and phosphorus, because they are the botanical equivalent of vampires, tapping into the internal plumbing system of their host to supplement their own nutrition.

This is common cow-wheat but for pictures of its much rarer cousin small cow-wheat Melampyrum sylvaticum take a look at Mark's Beating the Bounds blog.

Some plants (holoparasites) have taken parasitism one step further, losing their chlorophyll and becoming totally dependent on their host for all their nutritional requirements - you can find a common example here and an extremely rare and beautiful example here.