Every Wednesday, I hope to find a new ‘weed’ to investigate. My only criterion will be that I will not have deliberately planted the subject of our inquiry. Who knows what we will find…..
Common Toadflax (Linaria vulgaris)
Dear Readers, this week I have decided to celebrate a ‘weed’ that I have seen a hundred yards from my house in East Finchley, and also in the ravines in Central Toronto – Common toadflax. What a world traveller this plant is. In Canada, it is also known as Butter and Eggs, possibly a reflection on the delicious but dairy-heavy breakfasts that are available everywhere in that noble country. When I was a small child, my brother and I would pluck the flowers from Snapdragons in my grandmother’s garden and chase one another around whilst pretending to ‘bite’ with the blooms. It comes as no surprise that Common toadflax is also used around the world for the same kinds of capers, and that many of its other names refer to its shape – Calve’s Nose, Puppy Dog’s Mouths, and my favourite, Squeezejaws.
Common toadflax is native to Europe and most of Eurasia, but was introduced to North America about 300 years ago, and is listed in as a noxious weed in several provinces and states. It is certainly a tough, perennial plant, which can even survive hard-pruning, but it is useful for pollinators. Its flowers need a heavy insect to open them, and so, like our domesticated antirrhinums (which are part of the same family) it is a great favourite with bumblebees.
Common toadflax has been used to produce a yellow dye for cloth in Germany, and was boiled in milk as a flykiller in Sweden. It has been used medicinally for liver problems, maybe because its yellow colour indicated that it might be useful against jaundice. Its flowers were also used to make an eye ointment. Although the plant is not native to North America, it has been used by the Iroqouis as an ingredient in a potion against enchantment, and by the Chippewa people to counteract congestive diseases. There is something about its elegant shape and delicate colours that makes it look as if it would be health-giving, to my eye at least.
One of the most delightful alternative names for Common toadflax is ‘Imprudent Lawyer’ (sometimes written as ‘Impudent Lawyer’). How on earth this innocent flower came to be associated with the legal profession is anybody’s guess, but I fear that the plant has been given this name because of the size of its ‘mouth’. And while we are on the subject of names, ‘Brideweed’ and ‘Bridewort’ are yet more ways to refer to Linaria vulgaris. Is this because the freshness of the flowers made it perfect for a bride’s bouquet or is it, as described in Andy’s Northern Ontario Wildflowers because the plant was used as a cure for a pig disease called ‘Bride?’ The explanation, as with so many of these things, is lost in history, but how I love that one ‘weed’ can have so many different local titles. It seems to me that we name the things that we love and notice, and on that basis, Common toadflax is a very well loved plant indeed.
Dear Readers, you might think that the Royal Botanical Gardens, situated an hour’s train ride out of Toronto, would be a manicured, formal place, full of flowerbeds and statues and fountains. It does have these things, but it is also the starting point for a variety of trails which pass through woodland and wetlands, and which support an extraordinary array of wildlife and plants. For the past two years I have met up with my American naturalist friend Michelle, who drives from Youngstown in the USA so that we can go and explore together. Although we meet so seldom, I feel that we are kindred spirits – both of us are obsessed with gardening for wildlife, and with learning as much as we can about our local ecosystems. However, Michelle has a much bigger job than me, as the biodiversity of the eastern side of North America is much more complicated than that of the UK. To take just one example, there are 59 species of butterfly in the UK, compared to 110 species in the Toronto area alone.
As soon as we set off along the trail, we had the feeling that we were being watched. The eastern chipmunks appear within a few minutes of us starting our walk and look up at us with enormous eyes just in case we happen to have a sack of bird food with us. We don’t (at least until somebody takes pity on us later on and gives us some of theirs), but there was enough food already left on the fences along the trail to keep a whole army of chipmunks happy.
The name ‘chipmunk’ is thought to derive from an Ojibwe word meaning ‘he who descends the trees headlong’. These little rodents are fiercely competitive at this time of year – they need to gather as much food as they possibly can to enable them to survive the winter, and are not averse to stealing another chipmunk’s ‘stash’. Hence, when the chipmunks weren’t approaching us, they were chasing one another through the undergrowth.
And the chipmunks are not the only creatures who are stocking up on food. Other eyes are on us, too.
The birds also appreciate the way that humans often have pockets full of provisions – here, a chickadee eats some sunflower seeds from Michelle’s hand, while another one waits in the branches. These birds remind me so much of the great tits in my own garden, with their varied calls and opportunistic ways. As small birds both species will have their work cut out to survive the winter, and so they will need as many of these fat-rich seeds as they can get their beaks on.
The flowers here are very different from those that would be found in a UK wood . Here, for example, are some arrow-leaved asters. At least, I hope they’re arrow-leaved asters (aster experts, feel free to put me straight!) Ontario has a fantastic range of asters, which interbreed quite happily and cause a real headache for anyone trying to work out what species they’re looking at.
Arrow-leaved Aster (Symphyotrichum urophyllum)
Ontario is also blessed with a dozen or more species of goldenrod, which have a variety of flower types and preferred habitats. All of them seem to be beloved by pollinators.
As we passed through the woodland, and onto the boardwalk that goes through the marshes, we are lucky enough to bump into a man with a camera and a woman carrying a half-kilo of peanuts and seeds. This couple walk the trail every day, and by coincidence we’d met them during our previous visit, and had followed them on their rounds.
We asked them what was new, and as we were discussing the possibilities, there was a splash, and a pointy-toothed face peered up from the water. A muskrat was undulating between the mallards.
Muskrat (Ondatra zibethicus)
This was a new creature for me, a member of the sub-family that includes voles and lemmings, and hence not a true rat at all. Muskrats are thought to have a very important part to play in the preservation of wetlands – they eat some species, such as cattail and yellow water lily, in preference to others. Their populations are thought to cycle naturally – when very abundant, the muskrats will eat a lot of vegetation, which helps to keep the wetlands open. Their main natural predator is the alligator, but they are food to every kind of carnivorous animal, from pike to osprey to coyote. And humans have hunted them too, for their fur and as food. For several North American native peoples, however, muskrat played a vital part in the creation of the world, by bringing up the mud used to create the planet from the bottom of the primordial sea when all the other animals had failed.
After a few minutes, we realised that there were two muskrats, probably youngsters born this year. They are known to share the lodges of beavers, behaviour that was filmed during David Attenborough’s ‘The Life of Mammals’ series a few years ago. It’s not clear who benefits most from this arrangement, but maybe the shared body heat and the extra eyes to watch for trouble make it a most satisfactory cohabitation.
As we stood on the boardwalk, I saw a largish bird fly over. It seemed to have a white head.
‘Is that a gull?’ I asked Michelle.
‘It’s pretty big’, she said.
We watched for a few more minutes as it soared and banked.
‘It’s a Bald Eagle’, said Michelle. ‘Very rare around here’.
And so we stood as it banked in long slow arcs above the trees, and disappeared into the blue. What a surprise.
The birds below are rather commoner.
Turkey Vulture (Carthartes aura)
At one point, four turkey vultures were circling above us, riding the thermals on this unseasonably hot day. One way to tell them from other raptors is that they seem to tilt and correct themselves in flight, rather than holding their wings rigidly as the bald eagle had done. Turkey vultures are exclusively carrion eaters, and do not eat dogs, small children or prize chickens, in spite of their rather dark reputations. They are unusual among birds in having a well-developed sense of smell – they may quarter the ground searching for traces of the chemical ethyl mercaptan, which is produced by decaying bodies. This means that the birds can find food hidden under trees, where it is undetectable by sight. Unfortunately for the turkey vultures, other predatory birds watch what they are doing, and will follow them down when they find food, often displacing them from the corpse. However, if the dead animal is a large one, the turkey vulture (who has a surprisingly delicate bill for such a large creature) needs the larger birds to get through the hide. So, the turkey vultures wait around patiently, and mop up once the coast is clear. This is an example of mutual dependence, much like that between ravens and wolves in the northern forests – the ravens have been seen leading wolves to a corpse that is too difficult for them to open by themselves.
As we walk on along the boardwalk, the creek opens out, and we begin to see more water birds. At a distance, the one below looks very familiar, but as I get closer I realise that this is not the grey heron that I see at home, but an altogether more formidable bird, a great blue heron (Ardia herodias).
Great Blue Heron (Ardea herodias)
This bird has a height of 54 inches, and a wingspan of over six feet. It is the largest North American heron, and even at this distance it was impressive, striding purposefully through the water. Great blue herons are migratory, leaving Ontario for Mexico and South America during the long cold winters, although the toughest birds may stay, provided the water doesn’t freeze over completely. This bird is easily big enough to feed on anything from ducklings to turtles, fish to frogs and even, dare I say it, the occasional juvenile muskrat.
We walk on along the path. The creek broadens out further, and then comes to a halt beside a road, with a lake opposite, and some lorries extracting gravel on the hillside beyond. On our side of the tarmac there are thick beds of reeds, and along the edge is an array of asters and goldenrod and evening primrose, as pretty as anything that could be dreamed up by a garden designer.
What is not so pretty is a small brown snake, dead in the middle of the road with its head crushed. Was it sunning itself when a car went hurtling past? There is something about the precision of the injury that perturbs me, as if someone deliberately killed this animal while it was doing nothing except minding its own business. But then I look up as something else flies low over the trees beside the path, arching away over the reed beds. A large brown and white bird that looks strangely familiar. It isn’t until it passes that I realise that we’ve seen an osprey, a much commoner bird in North America than it is in the UK, and surprisingly widespread – I saw one in San Diego a few years ago. On the way back we check out any dead trees to see if the bird is perching, but we are only lucky enough to get this one glimpse. Still, to see a bald eagle and an osprey in one day is extraordinary luck, and neither Michelle nor I are complaining.
I see an old friend, too.
Monarch Butterfly
After seeing monarchs in Collingwood last week, I’ve continued to see them. Once, I saw one flying anxiously over the Distillery District in downtown Toronto. What a difference it might have made if the half-barrel containers full of impatiens and geraniums had contained something with a bit more nectar. But here along the creek there are lots of wild plants to feed on, and the monarchs are taking full advantage.
And then, as we come to the end of the boardwalk I see a bird that even I can identify.
Red-winged Blackbird (Agelaius phoeniceus)
The red-winged blackbird is said to be the commonest bird in North America, with an estimated 250 million breeding pairs. This has sometimes led to a difficult relationship with human beings: in 2009, it was estimated that over 950,000 birds were poisoned as ‘agricultural pests’ in the south-eastern USA, even though these birds also eat a large number of insects which are injurious to crops. As usual, the poisoning did not just affect the target species: the rusty blackbird (Euphagus carolinus) has declined by almost 99% since the 1960’s, and it is thought that these birds may have been caught up in the biocide, although habitat destruction has undoubtedly also played a part.
Rusty Blackbird (Euphagus carolinus) – see below for photo credit
And so, it’s time for lunch, and we head back to the main cafe in the Royal Botanical Gardens. But as we go in, we pass these strange characters.
I’m not sure exactly what these plants are, but to me they are full of character, like shaggy green gods waking up after a long sleep. Whether they have been designed to look like this, or have grown this way I have no idea, but they seem the very embodiment of a kind of vegetable intelligence, a different way of being in the world that we, with our mammalian senses, can barely begin to comprehend. If walking in nature teaches me anything, it’s how little I know, and how abundantly much there still is to learn.
Every Wednesday, I hope to find a new ‘weed’ to investigate. My only criterion will be that I will not have deliberately planted the subject of our inquiry. Who knows what we will find…..
Hoary Mustard (Hirschfeldia incana)
Dear Readers, the brassica or cruciform family of plants is a tricky one for the novice botanist. All those different rockets and cresses and mustards always make me scratch my head and run for help. So, when I found this week’s plant growing on a patch of disturbed ground by the edge of Coldfall Wood, I wondered about getting the identity correct. Fortunately our weed this week, Hoary Mustard, can be distinguished from its many relatives by having seed pods which some people compare to clothes pegs in shape, but which remind me of old-fashioned fountain pens. This has given the plant one of its alternative common names, Short-pod Mustard.
Hoary Mustard seedpods (By Harry Rose from South West Rocks, Australia (Hirschfeldia incana fruit3) [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons)
At this time of year the plant is a mass of long, wiry stems, each with a cluster of the typical four-petalled flowers on the top.
Like all of the cabbage family, the leaves are edible, and taste a little like rocket. They can also be used as a spinach substitute. It’s also one of the many plants that are used in Greek to make Horta, a cooked vegetable dish familiar to anyone who’s spent too much time sitting outside a taverna with a glass of ouzo.
Hoary Mustard was first recorded in the wild in 1837 (it comes originally from the Mediterranean) but in recent years it has been spreading from its heartland in London, and can now be found around the Severn Estuary, in East Anglia and in north west of England. It’s currently absent from Scotland and most of Ireland.
The word ‘Hoary’ probably refers to the grey-green colour of the foliage – this property is also picked up in the species name, ‘incana’, which is the Latin word for ‘grey’. In Australia, where it’s considered to be a noxious weed, the plant is known as Buchan Weed, probably because it grows in abundance along the banks of the Buchan river in Victoria.
The plant is also occasionally the larval foodplant of the Orange-tip Butterfly, who generally prefers to lay her eggs upon Garlic Mustard, but will manage with other plants if her favourite is not about.
So, here we have Hoary Mustard, another one of those leggy yellow-flowered plants that pop up as soon as the ground is dug up, and which go about their business largely unremarked. And yet, these plants are the closely relatives of so many of our foodplants – broccoli and cabbage, rocket and turnip, radish and even that superfood of the moment, kale. For the foods with a devilish hint of sulphur, or a tang of pepperiness, I give thanks to the wild brassicas, the plants that started it all.
Dear Readers, for the next two weeks my Saturday posts will be from Canada, where I’m visiting the friends and family who live on this side of the pond. For part of this week I’ve been in Collingwood, a town of almost 20,000 souls on the coast of Lake Huron, where I’m staying with my husband’s aunts, Rosemary and Linda, both keen wildlife and plant enthusiasts. Visiting this part of the world always reminds me of the Chinese phrase ‘Same-same, but different’ – so many of the plants and animals are familiar, but then there are those which are not. On a walk down to the lake shore I found the plant below. I’m sure that my North American readers will recognise it immediately but it was a complete mystery to me.
Milkweed (Asclepias syriaca)
Linda told me that this is Milkweed, is the food plant of the caterpillar of the Monarch butterfly. Its leaves contain toxins which make both the larvae and the adults poisonous to predators, which is probably some protection during the butterflies’ epic migration from Canada to Mexico, where they spend the winter.
Monarch butterfly laying eggs on Milkweed.Photo credit (1) below.
At this time of year Milkweed is covered in seedpods, which will soon burst to reveal a mass of fluffy seeds. These are so light and buoyant that they were used as an alternative stuffing for lifejackets during World War Two – children were encouraged to collect the seedheads, and over two million pounds of milkweed floss were gathered in one year. The slogan was that ‘Two bags save one life’, as it took two bags of floss to fill one lifejacket.
The latex-like white sap was also harvested during the war as a rubber substitute by both Germany and the US, although it proved to have too little of the key ingredient to be feasible.
The flowers, which appear between June and August, are an invaluable source of nectar for all kinds of pollinators. The pollen is stored in special sacs, called Pollinia, which attach themselves to the insect and are pulled away when the insect leaves, provided that it is big enough – non-native bee species may become stuck to the plant, and die. Milkweed has been used both as a source of sweetness by Native Americans, and as a way of making arrows poisonous. Few plants can have such a variety of contradictory uses.
Onwards! We advance along the paths beside the lake.
Canada Goldenrod ( solidago canadensis)
The road from the bus station at Barrie to our destination at Collingwood was lined with stand after stand of Canada Goldenrod. It is the dominant plant of roadsides at this time of year, and will be familiar to my UK readers as well, appearing in many situations where the soil is disturbed. It is also said to have become a terribly invasive plant in China, and is flourishing in the abandoned rice-paddies around the abandoned nuclear plant at Fukushima. Clearly this is a plant of extraordinary resilience and opportunism. In Canada, it is browsed by deer and is eaten by at least twenty species of birds and mammals. In Ontario, the local Ojibway people called the plant ‘Geezisomuskiki’, which means ‘Sun medicine’, and it has been used by various North American First Nations people for both veterinary and human medicine. The Thompson tribe bathed their children in a decoction of Goldenrod for its sedative effect.
Staghorn Sumac (Rhus typhina)
Staghorn Sumac is often seen growing along the railway lines in the UK, and is sometimes planted in gardens for its intensely red autumn foliage. It’s here in North America that it looks most at home, however, especially at this time of year, when the strange red fruits (called drupes) are beginning to ripen (the word ‘Sumac’ comes from an Arabic word meaning ‘red’). It is the source of the spice sumac, which has become very popular (especially with followers of chef Yotam Ottolenghi), but the seedheads are also used to make a pink soft drink called ‘Sumac-ade’ in North America. The leaves are added to tobacco and smoked by some Native Canadian peoples, and a dye can also be produced from the plant. Intriguingly, the wood of all Sumacs fluoresces under ultraviolet light, and I wonder if this is used to attract some nocturnal creature.
Sumac is a difficult plant to control, should one want to – cutting it down produces an array of sharp woody shoots. Apparently goats enjoy eating Sumac, but unfortunately they also enjoy eating pretty much everything else. As it is a plant that grows in poor, thin soil where other things are loathe to venture, it might be better, in general, to just enjoy it.
Common Eastern Bumblebee (Bombus impatiens)
Being on a new continent can feel a little like being illiterate – I don’t immediately recognise even the commonest of birds and insects. In the photo above, I could tell that I was looking at a bumblebee, but I had no idea what species. A quick look at the trusty internets told me that this was a queen Common Eastern Bumblebee, but to me she was a wonderful creature – her ashy thorax made her look like no bee that I’d ever seen before. No doubt she is topping up her reserves with nectar in order to allow her to hibernate through the long, cold Ontario winter. Bumblebees are well-adapted for cold conditions, and it’s thought that their larger size and thick coating of ‘fur’ developed to protect them in the tundra areas in which they first evolved. If last winter in Collingwood was anything to go by, she’ll need every layer of insulation that she can get.
New England Aster (Symphyotrichum novae-anlgiae)
The New England Aster is a plant that is often grown in gardens in the UK, but here in Ontario it is a native plant that grows in abundance, making a colourful counterpoint to the Goldenrod. Its flowers are much more to the reddish-purple end of the spectrum than most asters (though the photograph doesn’t really bring this out), and the plant seeds and leaves are eaten by everything from grouse to moose. Again, it has an Ojibway name – Waunissikaehniswung, which means ‘that which would kill pain’ – native peoples in Canada and the US have used a poultive of the roots for pain, and an infusion of the plant for fever.
And then, this afternoon, we went to visit Juliet’s farm. Juliet is a close friend of Rosemary and Linda, and a sculptor who made the wonderful piece below.
Her house is surrounded by fields full of New England aster and Goldenrod, Milkweed and Red clover. And, floating above the flowers, their wings like tangerine-coloured stained glass, were Monarch butterflies. As soon as one left, another arrived to take its place, like planes queuing up to land. I managed to get just one shot of a butterfly feeding, so anxious were they to fuel up and be on their way south. At a time when these butterflies are becoming more and more scarce, this one field drew them in from the four points of the compass, as if they knew that, among all the fields of maize and canola they would get a welcome here.
Like wild creatures the world over, Monarchs are becoming scarce, due to the destruction of their over-wintering sites, the industrialisation of agriculture, the increased use of pesticides and a variety of other factors. But here, the butterflies found a brief sanctuary before their journey south. Let us never underestimate the value that the right resource, at the right time, can make to the lives of individual animals, whether it’s a pot of early-flowering crocuses for the bumblebees or a whole field full of wildflowers.
Every Wednesday, I hope to find a new ‘weed’ to investigate. My only criterion will be that I will not have deliberately planted the subject of our inquiry. Who knows what we will find…..
Hemp Agrimony (Eupatorium cannabinum)
Dear Readers, I wonder if there was ever a plant quite as ramshackle-looking as Hemp Agrimony when it’s past its prime. The flower heads looks as if they are in need of a good comb, and when the seeds come the overall effect is of a gigantic thistle with bedhead. But if we look at the photograph above, we can see a hoverfly who is in no way put off by the general air of untidiness. For, of all the flowers that has self-seeded around my pond, Hemp Agrimony is among the most popular.
Like many plants whose blossom is made up of numerous small flowers, Hemp Agrimony’s nectar can be easily accessed by the more non-specialised pollinators, such as flies and hoverflies. And the multiplicity of blooms means that there is a lot of food in one place. Honeybees also have a great fondness for the plant, and when it’s sunny the bees drift drowsily over the dirty-pink flowers, which Richard Mabey compared to ‘whipped strawberry mousse’ in his book Flora Britannica.
Hemp Agrimony is a member of the Asteraceae, or Daisy family. You might expect that it has some psychotropic properties, what with it having the species name cannabinum, but this simply refers to the shape of the leaves. This doesn’t stop the occasional perfectly innocent Hemp Agrimony seedling being impounded of course, because botanical knowledge is not necessarily the first thing that they teach at Police Academy. Richard Mabey mentions that young Horse Chestnut trees have been taken into custody because their leaves also have a strange resemblance to the true Cannabis plant, at least if you’ve never seen one of the latter.
Hemp Agrimony is a native plant in the UK, and like so many plants that have been here for a while, it has some interesting folklore. One alternative name for the plant is ‘Holy Rope’ – the leaves of Hemp, which this plant resembles, were used to make rope, and it was believed that such a rope was used to bind Christ before his crucifixion. A more day-to-day belief was that if bread was placed on a bed of Hemp Agrimony leaves, it wouldn’t go mouldy. The plant has also been used medicinally, especially in the Netherlands where it was for jaundice, as a blood-purifier and as a cure for scurvy. It is said to be toxic, however, and it has been noticed that the iron-stomached goat is the only creature that will eat it.
Hemp Agrimony likes damp, shady places, and so is very at home beside the pond in my north-facing garden. It’s a perennial too, so all it needs is some cutting back to stop it becoming too much of an eyesore. I put the hollow stems beside the shed, where they will hopefully be used by hibernating insects. And next year, without any bother at all, it will be back as a late summer feast for pollinators. I am very happy to live with its wayward habit and general shagginess when the reward is such an abundance of insects and other invertebrates.
Resources this week include: Flora Britannica by Richard Mabey
Dear Readers, at this time of year a walk through the garden to get to the shed involves pushing through at least one spider’s web, strung at head height. I feel bad as the remains float in the breeze like so many silk curtains, but what can I do? The spiders are everywhere. One has strung her web between the wheelie bin and the drainpipe. Some have fixed their webs around the handles of the bins, so that taking hold of them on collection day is like pushing your hand through so much coarse hair.
The spiders have been here since spring – they don’t just appear as the days shorten, as I used to think. But for months, they have been tiny. Only in autumn do they start to come to our notice. Most European spider species will moult their skins five to ten times in their lives, growing larger after each episode of ecdysis (and what a fine word that is!). But in these late golden days, we start to notice the signs of the creatures for the first time. On a misty October morning, it may feel as if a hedge is more web than foliage.
The webs that spiders weave vary greatly between species, from the circular webs that we are all most familiar with in the garden to the sheets and traps made in hedges, or in the corners of windows. But, according to Michael J. Roberts in the Collins Field Guide to Spiders, the webs will vary according to the age and experience of the spider. With practice, you can determine the style of an individual spider. It’s easy to think of small creatures as identical automata, but science is showing us that there is great variation in ‘character’ even among animals that we’ve been taught to consider almost brainless.
Silk is not just for webs, however. Spiders use it in almost every aspect of their lives. The females use it to create an egg-case, which keeps their eggs together and makes them transportable. The silk also helps to prevent them from drying out. A female may leave drops of a pheromone on silk strands to attract the male, a kind of scented trail leading to her lair. The male puts his sperm onto a silk package in order to place it into the female. And, (for me the most wondrous use of all), spiderlings, especially money spiders, use an especially fine kind of silk known as gossamer in order to disperse. As Roberts puts it:
.’…the spider moves to a relatively high point, stands on ‘tiptoe’ pointing the abdomen upwards, and lets out strands of silk from the spinners. There may be one, or several threads, and pieces of fluffy white silk may be incorporated, increasing air drag like a kite. These strands may fall to the ground or become entangled, but success comes when they are carried upwards. The spiderling is very light and, when the pull of air current on silk is established, it lets go with the foot claws and sails aloft’.
Once launched, the little spiders have no control over where they go. They may perish on ice-fields, get eaten by swallows, fall into water or become food for other spiders. Nonetheless, this literal leap into the unknown seems much like what many young humans will have been doing in the past few weeks, as they start school or college, or leave home to go to university. Like all of us at the start of our adult lives, we jump and hope that some kind of net will appear.
So, what exactly is spider silk? It’s a form of protein, which is produced within the spiders’ body in the form of strands, and which is exuded by the spinnerets, two glands at the base of the spider’s abdomen. Whilst many invertebrates produce silk, it has reached its highest form in the spider: an individual spider can produce up to seven kinds of silk. Some of it will be thick and strong, for anchoring a web, or supporting the spider as it swings from one point to another at the start of web construction. Some silk will be covered in sticky globules, for catching prey. Yet another is used to wrap the eggs, or to build the sperm package. The names for these different kinds of silk form a kind of poetry: ampullate, aggregate, tubiliform and aciniform.
We often hear that spider silk is as strong as steel, and so it is. But what is truly remarkable is its toughness. Toughness is the measure of how hard it is to break a filament of a material, and in this the kind of silk used for supporting the web is tougher than any man-made substance. Darwin’s Bark Spider produces the toughest silk of all, which has been estimated to be ten times as tough as Kevlar. This is a species from Madagascar, which can build webs with strands of up to 25 metres long across rivers. I imagine walking into a web like this would be like walking into a cheese wire.
Strands of silk made by Darwin’s Bark Spider over a river in Madagascar. Photo credit and link for this and the orb web at the bottom of the piece.
Darwin’s Bark Spider also makes the largest orb web of any species as well, at over 30 square feet.
The orb web of Darwin’s Bark Spider (see below for photo credit)
There may be occasions when a spider needs to cut through the silk. For example, a wasp may fly into a web, or the spider may need to do some tidying up because her web has become too visible. Although it might look as if she is biting through the strands, in fact she uses a chemical reaction to cut the silk by regurgitating some of her stomach juices. And because producing silk is such an expensive activity for the spider, she will eat her old webs before she produces a new one, so that the protein is recycled.
For all their strength, though, the thing that I love about spiders’ webs is their combination of strength and delicacy, the way that they are both strong and as light as a cloud. And they so often go unnoticed, maybe until a foggy morning shows that every inch of a box hedge is connected with a lace-like lattice of silk, as beautiful and tattered as Miss Havisham’s wedding dress in Great Expectations. It reminds me that invertebrates truly are the little things that run the world. They outnumber us billions to one, but go about their business largely unremarked – at least until the House Spiders start to emerge in search of their mates, or there’s a headline about a tarantula in a bunch of bananas.
This autumn, I have suddenly been offered some unexpected work, which will take me away from home. As always, I have mixed feelings: I am delighted to be able to earn some money, and sad that I will be away from the things and people that sustain me. But when I feel down, I remind myself that wherever I am in the world, there is always a weed in the pavement, or a spider in the park. If we have a passion for these things, we are never far from home.
“Caerostris darwini web” by Ingi Agnarsson, Matjaž Kuntner, Todd A. Blackledge – Lalueza-Fox, C., Agnarsson, I., Kuntner, M., Blackledge, T. A. (2010). Bioprospecting finds the toughest biological material: extraordinary silk from a giant riverine orb spider. PLoS ONE 5: e11234. doi:10.1371/journal.pone.0011234. Licensed under CC BY 2.5 via Commons – https://commons.wikimedia.org/wiki/File:Caerostris_darwini_web.png#/media/File:Caerostris_darwini_web.png
Every Wednesday, I hope to find a new ‘weed’ to investigate. My only criterion will be that I will not have deliberately planted the subject of our inquiry. Who knows what we will find…..
Red Valerian (Centranthus ruber)
Dear Readers, Red Valerian is one of those plants that seems to be cropping up all over the place. In the photo above, I found it growing on the banks of one of the streams in Coldfall Wood, here in north London.The photos below are from my parents’ village of Milborne St Andrew in Dorset, where the pink form proliferates over the more usual red-flowered type. If you are lucky (and I was not this time) you can also see a white-flowered form.
Now, the first thing to say is that this is not the plant that is used to make all manner of herbal sedatives – that is Common Valerian (Valeriana officinalis), which I will hopefully find at some point and will blog about separately. Red Valerian is in the same family, but is a naturalised plant, whose native habitat is the Mediterranean. It was first recorded in the UK in 1593, and was reported in the wild for the first time in 1763. It has a tolerance for very alkaline conditions, and is hence sometimes seen growing in the mortar in old walls, both here and in France and Italy.
Close up, you can see that the head is made up of hundreds of tiny 5-petalled flowers. As the year goes on, these are replaced by the fluffy seeds which will set up home with the slightest encouragement. Red Valerian has a reputation for being invasive, but is easily pulled up if it occurs somewhere that it is not wanted. It is loved by bees and butterflies, and by one very special visitor in particular, which seems to prefer this plant above all others.
On at least three occasions, people that I know in the UK have told me that they have seen a hummingbird in their garden. I have to tell them that we don’t actually have hummingbirds in the Old World, but what they have seen is no less remarkable – it’s a Hummingbird Hawk Moth, which, with its large size, thrumming wings and zig-zag flight pattern is easily mistaken for a small bird. I have always been a little jealous because in all my wanderings I have never seen a Hummingbird Hawk Moth for myself. Then, a few weeks ago, I finally saw one feeding on Red Valerian in my parents’ garden. I heard the moth before I saw it, a low-pitched buzzing like a giant bee, and just had time to see the blur of copper wings, and to take in the furry body and the long, long tongue before the moth moved on, at speed. Its caterpillar is no less remarkable, and these moths have been seen laying their eggs on Red Valerian as well as feeding on it, so if you see a patch of the plant, have a good look! You can tell a Hummingbird Hawk Moth caterpillar by the distinctive blue and orange spine at the back end.
Local names for Red Valerian have always had a certain boozy, maritime quality – it’s known as Kiss-me-quick, Drunkards and Betsy in various parts of the country. Is it because, when it hangs down from the walls that are its favoured habitat, it sways tipsily in the breeze? I have no idea, but it does lend a certain Mediterranean ambiance to the places that it grows. I half expect the walls of the half-bricked houses to become white-washed, and to smell the sea.
There are rumours that Red Valerian can be eaten – the Plant Lives website describes how the leaves have been used in salads ‘in spite of their catty smell’, and that apparently the root can be eaten as well. Even more enticingly, it says that the seeds of Red Valerian have been used for ’embalming the dead’, though this may be because of a confusion with a similar plant called Spikenard, or False Valerian root, which was used by the Egyptians during mummification. It has no medicinal properties that anyone has discovered so far.
Something that intrigues me about Red Valerian is that it is often also known as Jupiter’s Beard. I had never thought of Jupiter, king of the gods, as being a red-head, but I’m sure there is absolutely no reason why this shouldn’t be the case. The plant is also known as Devil’s Beard – red-headed people have, unfortunately, been associated with the devil for a long time, which just goes to show how stupid prejudice can be. But whatever it’s called, this is a long-flowering, insect-friendly plant which brightens up any backyard, wall or parking lot. It’s a great example of a ‘weed’ with charm.
Dear Readers, while I was in Milborne St Andrew in Dorset with my parents this week, I went out in search of autumn. It is my favourite season, with its lengthening shadows, golden light and occasional sun-blessed days. And being in the autumn of my own life I sometimes feel a certain restlessness, a kind of scratchy irritability and dissatisfaction. At times like these, I need to get out and walk, and tune in to something that’s outside my own head. Sometimes, it takes me a while to find what I’m looking for, to slow down enough to ‘see’ properly. But this time, I was pummeled into paying attention by creatures that were even more restless than I am.
House Martins (Delichon urbica)
House Martins are among the first birds to arrive in the UK from sub-Saharan Africa, and the last to leave. On this late August day, they seem deeply conflicted. One minute they land on the red-tiled roofs at the end of the village, and preen energetically. The next they fly up in a great flurry, circle the roof and land again. They resemble nothing so much as a shoal of little fishes, darting this way and that, directed by some imperative that is invisible to mere humans. The distinctive blue-black and white plumage of the adult birds reminds some people of orcas.
All the time, the House Martins call, a sound like a bagful of pebbles being shaken vigorously. This is an anxious time for them. For the newly fledged youngsters, it will be the first time that they’ve made their epic migratory journey. In a good year, House Martins will have two or three broods, and all those fledglings will accompany their parents on the trip south. What triggers this journey is probably a combination of the shortening day-length, falling temperatures and the decline in insect numbers. This last is vital: House Martins feed only on insects, catching them in mid-air. Without these birds, and others like them, our mosquito and midge problem would be much worse than it is.
Not everyone is delighted to have House Martins or Swallows or Swifts nesting under their eaves. The birds can be messy and noisy for the few months that they are rearing their young. Most people tolerate the inconvenience for the delight of seeing the birds soaring and barrel-rolling over their houses, and for the joy of their return every spring, for these birds are intensely faithful to their nest sites, and will re-use a nest if they can, patching it up with mud if it’s been damaged by the winter weather. But for some people it’s a nuisance too far, and the nests are destroyed, or wire is used to deter the birds on their return. I can only imagine the confusion when, having braved desert, mountain, ocean and conurbation, the birds arrive at their destination only to find that their nest, lovingly built with over 1000 beakfuls of mud, no longer exists. House Martins have declined significantly in the UK in the past few years, enough for the RSPB to put them on their Amber list of conservation concern. This may be down, in part, to the lack of suitable nest sites, as new houses and farm buildings often lack the overhanging eaves that are essential to create the nest. I’m sure that our addiction to pesticides will also not be helping with the food supply.
We know very little of what happens to House Martins once they reach their wintering grounds – of the 290,000 birds ringed in Britain and Ireland, only one has been recovered south of the Sahara. In fact, there is a theory that the birds spend the winter in the air, eating insects, and only come to earth in uninhabited forest regions to roost. This is not as unlikely as it sounds: while the breeding population of House Martins spends the hours of darkness on the nest, unmated birds are thought to roost on the wing at elevations of over 3300 feet. But wherever they go, there is a certain sadness in their leaving. By the time I left my parents to come back to London, most of the House Martins had gone. This is all to the good, of course – any bird that stayed in the UK would undoubtedly die of starvation. We must make peace with their going, because we know that it is what they need to do. And, as in so much of life, the letting go is all.
Resources this week included Mark Cocker’s Birds Britannica, a wonderful guide to both the facts and folklore of British birds.
Every Wednesday, I hope to find a new ‘weed’ to investigate. My only criterion will be that I will not have deliberately planted the subject of our inquiry. Who knows what we will find…..
Purple Toadflax (Linaria purpurea)
Dear Readers, this plant is so delicate and elegant that for a while I was convinced that it was solely a garden flower. But then I saw it cropping up on wasteland, and seeding itself in hedgerows in Dorset and Somerset, and came to the conclusion that it has hopped over the fence and established itself ‘in the wild’. And once I noticed it, I started seeing it everywhere. The photos here are from my Aunt Hilary’s garden in Somerset, but there is plenty of Purple Toadflax on the mean streets of North London, where only those carrying skinny lattes dare to tread.
And what a sweetheart it is! The flowers are popular with honeybees, and resemble those of a pint-sized snapdragon (and indeed, the plant is also known as Perennial Snapdragon). In addition to this, the leaves are the foodplant of the caterpillars of the Toadflax Brocade moth (Calophasia lunula). These are spectacular creatures, with their neon yellow stripes and black spots, and it’s almost worth ‘encouraging’ Purple Toadflax just for a chance of seeing them. For some more splendid photos, have a look at the Back in Birdland blog. In North America, where Common Toadflax (Linaria vulgaris) has become a problem, the Toadflax Brocade has been introduced as a biological control. In the UK the moths are at the northern end of their habitat range, and are classified as rare, so if you see one, or the larvae, you are extremely lucky!
Purple Toadflax was introduced to the UK from Italy in the 1830’s, and was recorded in the wild shortly afterwards, thereby joining the native Common Toadflax and introduced Ivy-leaved Toadflax. It is a most undemanding little plant, flowering from May through to September and providing nectar the whole time. The Guardian’s Alys Fowler championed it as a garden plant a while back, and for information on the available varieties, you can have a look here. I must admit to a preference for the original purple version, though you can now buy it in white, pink and mauve.
Purple Toadflax also seems to be a favoured nectar-plant of the rare Wool Carder Bee (Anthidium manicatum), a large and solitary bee which uses the hairy leaves of plants like Stachys byzantina (Lamb’s-ear) in order to line its nest. What a pleasure it would be to have these insects in the garden! I can imagine planting up a pot of Purple Toadflax next to a pot of Lamb’s Ear in my front garden next year, just to see what happens.
Common toadflax is native to Europe and most of Eurasia, but was introduced to North America about 300 years ago, and is listed in as a noxious weed in several provinces and states. It is certainly a tough, perennial plant, which can even survive hard-pruning, but it is useful for pollinators. Its flowers need a heavy insect to open them, and so, like our domesticated antirrhinums (which are part of the same family) it is a great favourite with bumblebees.
Common toadflax has been used to produce a yellow dye for cloth in Germany, and was boiled in milk as a flykiller in Sweden. It has been used medicinally for liver problems, maybe because its yellow colour indicated that it might be useful against jaundice. Its flowers were also used to make an eye ointment. Although the plant is not native to North America, it has been used by the Iroqouis as an ingredient in a potion against enchantment, and by the Chippewa people to counteract congestive diseases. There is something about its elegant shape and delicate colours that makes it look as if it would be health-giving, to my eye at least.
One of the most delightful alternative names for Common toadflax is ‘Imprudent Lawyer’ (sometimes written as ‘Impudent Lawyer’). How on earth this innocent flower came to be associated with the legal profession is anybody’s guess, but I fear that the plant has been given this name because of the size of its ‘mouth’. And while we are on the subject of names, ‘Brideweed’ and ‘Bridewort’ are yet more ways to refer to Linaria vulgaris. Is this because the freshness of the flowers made it perfect for a bride’s bouquet or is it, as described in Andy’s Northern Ontario Wildflowers because the plant was used as a cure for a pig disease called ‘Bride?’ The explanation, as with so many of these things, is lost in history, but how I love that one ‘weed’ can have so many different local titles. It seems to me that we name the things that we love and notice, and on that basis, Common toadflax is a very well loved plant indeed.
![By Harry Rose from South West Rocks, Australia (Hirschfeldia incana fruit3) [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons](https://i0.wp.com/bugwomanlondon.com/wp-content/uploads/2015/09/hirschfeldia_incana_fruit3_14629597514.jpg?ssl=1)
![Hummingbird Hawk Moth (Macroglossum stellatarum) (By Marcel Oosterwijk [CC BY-SA 2.0 (http://creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons)](https://i0.wp.com/bugwomanlondon.com/wp-content/uploads/2015/09/hummingbird_hawk-moth_in_ec49firdir_turkey.jpg?ssl=1)
![Lamb's Ear (Stachys byzantina) (By Jean-Pol GRANDMONT (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0) or GFDL (http://www.gnu.org/copyleft/fdl.html)], via Wikimedia Commons)](https://i0.wp.com/bugwomanlondon.com/wp-content/uploads/2015/08/0_stachys_byzantina_-_yvoire_2.jpg?ssl=1)
