Bad Botanist

‘Bogy and such like moorish places’; a paean to peat

Back in 2009, I spent a week at the Field Studies Centre in Preston Montford, attending a course for my OU degree. There was a lot to learn, each 12-hour day packed with activities vital to the budding environmental scientist. One day was all about soils. After a crash course in the use of soil sampling tools – long, corkscrew-like augers and broad metal pots called ‘dollies’ that were hammered into the ground – we were driven into the wilds of Shropshire and flung out of the minibus at random intervals, with instructions to grab a sample and be back in fifteen minutes or we wouldn’t have time to do the lab analysis. It was all quite intense.

Around midday, after bumping over a bridge so steeply curved it nearly grounded the bus, we were led up a narrow path, past a belt of trees, and came out into one of the most wildly beautiful places I had ever seen; Whixall Moss.

It wasn’t beautiful in the conventional way. That same day, we had already visited much prettier places. Whixall Moss wouldn’t feature on a holiday postcard, like the picturesque stream at Carding Mill Valley. Nor would it inspire a sweeping landscape painting like the great winding swell of the Long Mynd escarpment. It was a bleak beauty; a flat expanse of brown grasses rattled and rustled in a ceaseless wind, which drove ripples across dark pools under grey, scudding clouds. This was a landscape that didn’t care if you liked it or not, and it filled me with awe.

Alas, there was no time to appreciate it further. We thwacked our dollies into the earth and extracted discs of damp, dark-chocolate soil. Then it was back on the bus – in my case with several regretful glances back over my shoulder.

Those dark discs were a very special substance; peat.

Peat formation

Whixall Moss is a raised peat bog. The word ‘bog’ sadly has rather negative connotations. It suggests stagnant, stinking waters, and conjures up images of dangerous marshes that can suck in unwary travellers, or harbour some kind of swamp monster – a narrative that goes back at least a thousand years to Beowulf. But to a naturalist, bogs are marvellous places. Indeed Whixall Moss is a Site of Special Scientific Interest (SSSI), thanks to its distinctive ecology.

Raised bogs form when a wet hollow becomes filled with vegetation, notably sphagnum mosses. These act like a sponge, absorbing and retaining rainwater to create an area that remains wet even if it is not connected to any waterways. Over time, the moss slowly dies and more grows on top until it is above the level of surrounding land – hence ‘raised’ bog. This is a very slow process, with the bog growing by about 1mm each year. A mature bog can take centuries to develop. Meanwhile, in the dark, waterlogged conditions under the surface, the decomposing vegetation is slowly turning into the fibrous, dark soil that we recognise as peat.

Plants of peat

These ‘bogy and such like moorish places’, as described by John Gerard in his 1597 Herball, are a challenging habitat – low in nutrients, permanently wet and highly acidic. It is not surprising that many bog plants are specialists, as extraordinary as their environment.

Sphagnum moss; the ‘bog builder’

The Sphagnum family includes many species of bog-forming mosses, which can form a carpet of many colours.

As well as acting like a sponge by absorbing many times its own weight in water, sphagnum makes that water slightly acidic. This means that moss is both absorbent and antiseptic – qualities that have made it a natural wound dressing, used as recently as the First World War. This is doubtless the inspiration for the ‘bloodmoss’ described by Philip Pullman in his Dark Materials trilogy.

Common cotton-grass (Eriophorum angustifolium)

Gerard’s insouciance in classifying this plant shows he is a man after my Bad Botanist’s heart. ‘This strange Cotton-Grasse doth rather resemble grasse than rushes, and may indifferently be taken for either, for that it doth participate of both.’ Much as I would like to be indifferent, I have a responsibility to be accurate, so am duty bound to say it is neither a grass nor a rush, but is in fact a sedge. I can’t improve on Gerard’s description of the stems though, ‘bearing at the top a bush or tuft of the most pleasant downe or cotton, like unto the most fine white silke’. A mass of cotton-grass stalks dancing in the breeze is a charming sight.

Cotton-grass can survive in waterlogged soil because it can snorkel! It has air canals in its roots which suck down air from the stems above ground. It copes with low nutrients due to its excellent recycling abilities; when it dies down in winter, the nutrients in the tissues are drawn down into underground bulbs and used again next spring.

Round-leaved Sundew (Drosera rotundifolia)

Sundew deals with the low nutrients of peat soil by catching its own food. Delicate hairs on its leaves exude a sticky, sugary ‘dew’ which both attracts and traps insects. The leaf slowly rolls up to enclose its prey, and then secretes enzymes to digest it.

Sundew has been used in folk remedies as a skin treatment and as a cough cure, and has been found to have antimicrobial properties.

Bog asphodel – Narthecium ossifragum

The yellow stars of bog asphodel are almost too bright for their tawny-brown surroundings. The species name ossifragum means ‘bone-breaker’ – it was thought to make sheep’s bones brittle if they grazed on it, but the more likely culprit is that the wet soils in which the plant grows tend to lack calcium. Like cotton-grass, it recycles nutrients into underground bulbs.

Peat bogs and climate change

Peat isn’t just a wonderful habitat. The slow build-up of organic matter stores carbon, and in the wet, anaerobic conditions (i.e. with no oxygen available), it remains in the ground rather than decaying and producing the greenhouse gas carbon dioxide. Systems that keep carbon locked up are known as ‘carbon sinks’, and in the UK, our largest sinks are peatlands, storing around 3.2 billion tonnes of carbon.

You’ll hear much more often about tree planting being a great planet-saving panacea, and indeed growing trees can suck in and sequester carbon at a faster rate. However they also release it, through respiration – at night they ‘breathe’ out carbon dioxide, just like us! – and leaf decay. Peat bogs, however, hold on to their carbon indefinitely. As long as they remain wet, they can store 10 times more carbon per hectare than any other ecosystem.

Unfortunately, land use change can convert peatland from a carbon sink to a carbon source. In some places, notably Ireland, cut and dried bricks of peat have traditionally been burned for heating and cooking – a form of fossil fuel. This is less common now, but worldwide, peatlands are being drained and dried, for agriculture or (ironically) tree planting. When they dry out, their carbon combines with oxygen in the air, forming carbon dioxide. The Wildlife Trusts estimate that degraded bogs in the UK alone are releasing about 23 million tonnes of carbon dioxide equivalent each year.

How does your garden grow?

Perhaps the most pernicious and tragic agents of peatland destruction are the people who you’d think would treasure it most; gardeners.

Peat is a perfect growing medium for plants and seeds. It holds on to water and nutrients while the light structure keeps soil aerated. Its use as compost developed in the 1960s, along with the rise of suburban gardening and the arrival of garden centres. Customers cheerfully took home sackfuls of the stuff for pots and as a soil improver. A colourful display of front-garden flowers may come at the price of the wholesale destruction of rare habitat and unique plants, as the waving, rattling grasses are bulldozed away into a hellish ruin to harvest the profitable black gold. It is ecocide on a sickening scale, all to pander to the wishes of people who claim to love plants.

This is a habitat, remember, that takes centuries to recover. According to the Wildlife Trusts, over the last 100 years, peat cutting, drainage and afforestation has resulted in the loss of 94% of raised bog in Britain and 99% in Ireland – and 2.1 million cubic metres are still being extracted for horticultural use every year.

The damage caused by peat harvesting has been recognised since the 1970s, and wildlife charities have been calling for a ban on peat products since then. Yet peat sales have continued throughout, the public largely ignorant and governments largely uncaring about the wholesale destruction caused by the nation’s gardeners. I got my first garden in 1997 and have never bought peat compost, but then I was a member of several wildlife charities long before that, and had been horrified by images of black wounds gouged across golden grasslands in their magazines. Such images were rarely shown in the popular press. The destruction is as terrible as deforestation in the Amazon, but it never got the same headlines.

In 2011, in a half-hearted attempt to address the issue, the government set a target for all compost sold to the public to be peat-free by 2020. The main flaw in this plan was that the target was voluntary. Not surprisingly, no major retailers met the target. This shameful lack of action is being called out by wildlife and environment charities. In June this year, 27 charities wrote to those retailers that were still failing to take action, asking them to put their money where their greenwashed mouths were.

What can I do?

If you’re a gardener – DON’T buy peat-based compost. There is no excuse. Alternatives are now readily available, and have improved a lot over the years. if you can’t see one, ask.

If you can, don’t buy plants raised in peat, either. This is much harder to do, but a list of peat-free nurseries is available – and if you’re feeling brave, ask your garden centre if they are sourcing peat-free plants.

You can also sign the Wildlife Trust’s petition calling for an immediate ban on peat compost.

Finally – if you can, visit a wetland and experience its wild beauty for yourself. I can’t find a specific listing for bogs and moorlands – please let me know if you find one! – but you could start with the Wildlife Trust nature reserve list – try putting ‘bog’, ‘moss’, or ‘moor’ in the keyword search.

That whistle-stop minibus tour left its mark on me. Two years after rushing off with my little disc of peat, I booked a week’s holiday in Shropshire, and returned, with my husband, to Whixall Moss. We spent a day there, giving it the hours of appreciation it deserved, surrounded by the rustling grasses and the endless, roiling sky.

Peat resources

Information about peat bogs:

Information about peat degradation and the climate:

https://www.forpeatssake.org.uk/issue
https://friendsoftheearth.uk/climate/why-peat-good-climate-and-nature-guide
https://www.wildlifetrusts.org/ban-sale-peat (Includes quiz!)
Natural England Research Report NERR094 – Carbon storage and sequestration by habitat: a review of the evidence (second edition), 20^th April 2021 – available from http://publications.naturalengland.org.uk/publication/5419124441481216
re-peat is a youth-led collective looking to re-educate the world about peatlands – see their website or find them on Twitter, and watch this lovely TED talk by Ireen van Dolderen.

Photographs

All available from Wikimedia Commons, apart from Common Cotton-grass which is my own.

Bog grass and Water, Whixall Moss and Lake on Whixall Moss – both by Espresso Addict ,CC BY-SA 2.0
Sphagnum moss by Anton Papić, CC BY 3.0
Drosera rotundifolia, Round-leaved Sundew by Sarkan47, CC BY-SA 4.0
Narthecium ossifragum, Bog Asphodel by gailhampshire from Cradley, Malvern, U.K, CC BY 2.0
Peat harvester at Ryeflat Moss by James T M Towill, CC BY-SA 2.0
Peat extraction Co Donegal by Jonathan Billinger, CC BY-SA 2.0
Peat harvesting from Carnwath Moss by M J Richardson, CC BY-SA 2.0
Industrial peat harvesting in the Bog of Allen by Sarah777, public domain

Magnificent Meadows (2): Mini-meadow update

Today is National Meadows Day – rather a damp one where I am! Wildflower meadows are a unique habitat that we don’t have nearly enough of. Their flowers are hugely important for bees and other pollinators, and they are a wonderful place to be, although maybe not when the grass is soaking wet like today.

I wrote a post on meadow habitats a couple of years ago. In that post, I mentioned that I had just started up a mini-meadow on my front lawn. The main approach was simply to leave the area unmown and see what came up – that way, I know that anything that does arrive is already suited to that space, its soil and light levels. This method produced plenty of dandelions and creeping buttercups – no surprises there – but also a patch of selfheal (Prunella vulgaris), a fair amount of clover and trefoil, and some impossibly tiny thyme-leaved speedwell (Veronica serpyllifolia).

I also bought a few wildflower plug plants from the local wildflower nursery run by Avon Wildlife Trust. It’s now called Grow Wilder and it has got an online shop! Not all of the plug plants took to the area – I never saw the oxeye daisies again – but some were happy enough to pop up again the next year.

Two years on, and having politely ignored comments from my husband about ‘too many dandelions’ (too many by whose count? Not a bee’s!) it really is starting to look more like a meadow. The Red Campion has rewarded me by producing little paper potfuls of seeds which I have strewn around the place, and several others including Hairy St John’s Wort (Hypericum hirsutum) and Lady’s Bedstraw (Galium verum) are going strong.

The delightfully named Fox and Cubs (Pilosella aurantiaca) – like an orange dandelion, which bears flowers in clusters, a large one surrounded by several small ones, hence the name – is doing particularly well this year, with more flowers popping up every week and marching across the area like a determined tawny army.

I am most pleased about my Yellow Rattle (Rhinanthus minor). This flower is parasitic on grass – in fact, the Grow Wilder nursery found that seeds grown in pots don’t survive unless some grass is grown along with them. The Yellow Rattle weakens grass, allowing other wildflowers to take over. I sowed seed I had gathered from other meadows in 2019, and was disappointed when only a couple of flowers came up in 2020. But this year, a whole patch has appeared, and there is noticeably less grass and more clover where it is growing.

To celebrate National Meadows Day this year, Plantlife has started up a new online Meadows’ Hub, where you can find out everything you ever wanted to know about creating and maintaining a meadow – so now you’ve all the more reason to grow your own.

City Nature Challenge 2021: My tips for plant photography

Next weekend (April 30 – May 3) sees the annual City Nature Challenge. This international ‘citizen science’ project asks people around the world to find and record the wildlife living around them. It helps to gather a huge amount of data, and gets people outside, appreciating the nature on their doorstep. Despite the name, the Challenge isn’t just about urban wildlife – it takes in the suburban and rural hinterland too. I take part in the Bristol and Bath one, which is co-ordinated by the Bristol Natural History Consortium.

You can record any wildlife you like – animals, birds, insects and plants. Obviously I’m all about the plants, and they tend to make up the bulk of observations as they are easy to photograph – though the highlight of 2020 in Bristol was definitely the seal spotted in the River Avon. There’s also a bit of informal competition as there are league tables for the most observations, most species and most identifications in your project area. Last year, despite lockdown, 550 people took part around Bristol and Bath, submitting 8,875 records of 1,350 species.

The project uses the iNaturalist smartphone app, or you can upload photos to the iNaturalist website. I have found iNaturalist absolutely fantastic for plant ID. Just show it a photo, and the magic algorithm will tell me what it is most of the time – or at least helps me get close.

However, it doesn’t rely on algorithms alone. To count as a ‘research grade’ observation, every photo on iNaturalist has to be identified to species level by at least two human beings, usually the original observer and one other person. If someone disagrees with the original identification, it’s back to square one – but I’ve learned a lot from my mistakes, thanks to the patience of other users. I always try to identify a few photos from other people whenever I post to the site, as a way of giving back.

The identification screen presents a gallery like the one below. Each picture needs checking, and the City Nature Challenge produces hundreds of these screens for each region.

For the last couple of years I have contributed to the Bristol and Bath challenge by trying to identify as many of the easier plant photos as I can in order to free up the ‘proper botanists’ for the difficult stuff. In doing so, I have learned a lot about what makes a good photo for identification purposes, and what has me shouting at the screen ‘And just HOW is anyone supposed to identify THAT?!’

So, if you’re up for joining in – and I heartily recommend it – I have noted below some of my own top tips on recording plants for the City Nature Challenge. Please note, I am NOT an official member of the Challenge team: this article is entirely my own and reflects my personal opinions, not official guidance. But I’d like to make life a little bit easier for all those hard-working, mostly voluntary, identifiers!

Some general tips…

Focus, focus

Plant recorders have a massive advantage over their bird and animal counterparts – their quarry will sit still while they take a picture. If your subject is in motion then blurred shots are forgivable (the Audubon Society’s #WorstBirdPic meme even makes a thing of it)! But with plants you can always try again. If you can’t focus on a tiny flower, try putting something next to it that the camera can latch on to – your own finger will do.

Tiny moschatel is hard to focus on – try adding a finger!

Does it matter? Some plants can be identified from a fuzzy image, but for others, detail is important. Presence or absence of stem hairs, for example, or the number of stamens on a flower, can make the difference between a species-level ID and the ‘yes, it’s a plant’ general bin.

One species per picture

Each observation must be of just one species. Some photos show beautiful floral meadows or patchwork woodland floors. Lovely, but what are we identifying? Make sure you’re as close as possible, or crop the shot, so only one species is in view.

Save the woodland carpet for your Zoom background and get the plants ready for their close-up – here they are bluebell, wood anemone and lesser celandine.

Self-isolate

The plant should be distinguishable from the background. If it’s against a wall or tree trunk that’s ideal, but if it’s in a meadow or wood it will just be green against green. Put a bag or coat behind it if you need to – this is for ID, not winning BBC Wildlife Photographer of the Year.

Flowers

Many recorders will take one lovely shot of a fully open flower, submit it, and move on. For some easily identifiable species this might be sufficient, but there are some tricky customers. You can upload more than one photo for each observation, so if in doubt take several views:

Take a closeup view of the flowerhead if you can; for single flowers, take front, back and side profile.
Don’t forget the leaves, which can be really important for ID. If there appears to be more than one leaf shape make sure they are all there (e.g. many plants have differently shaped basal leaves and stem leaves).
If you can get the whole plant in shot that can be helpful for seeing growth habit.

This is probably too much work for every flower you find though – and I should be the first to say, I don’t do this for all of them! So to concentrate your efforts, some common but problematic species to look out for are:

Buttercups – We have three common species, Meadow, Creeping, and Bulbous. All the flowers look pretty much the same, but the leaves are different. Bulbous buttercups also have reflexed sepals, i.e. the little green structures under the flower are bent back, whereas in other buttercups they are flat against the flower petals.

Top left is definitely a buttercup – but which one? Top middle and right are Bulbous Buttercup, showing leaves and reflexed sepals; the bottom row shows three views of Meadow Buttercup.

Violets – seeing the ‘spur’ at the back of the flower can be a key ID point.

Left to right: Sweet Violet, with rounded sepals and a stout spur; Early Dog Violet, pointed sepals and dark, slender spur; Common Dog Violet, pointed sepals and a pale spur with a notch in it. They can’t be easily distinguished from only ‘face on’ photos.

The Asteraceae family (Things That Look Like Dandelions) – leaf shape and hairiness is important, and some flowers have tell-tale stripes on the back of the petals.

On the left is Mouse-ear Hawkweed, with red-striped petals and rounded, hairy leaves; on the right is Common Cat’s-ear, with brown-striped petals, dark bracts on the stem, and lobed leaves.

Trees

Leaves and buds, and their growth arrangement, are most important. Get a closeup of the branch with a few leaves and/or buds on it.
Photograph the bark on the main trunk.
If any flowers, fruits or catkins are present, photograph those too.

Grasses and sedges

OK I admit it, if I see a photo of a grass I will probably pretend I never set eyes on it and move on, leaving it to the experts. But there are a few I can do, given the right photo.

Show the growth habit. Some grass species form uniform meadows, other grow in bunches or ‘tussocks’ – it’s worth taking a general shot to show which it is.
Pull a piece out right at the bottom, and photograph the whole shoot in closeup. Shape, colour and hairiness all help with ID.
Really hardcore stuff, requiring a good macro lens; pull down a leaf, peer at the base and see if you can see a white membranous tissue, the ‘ligule’, to photograph. Grass experts just LOVE these. Grass experts are funny.
If there is a seedhead that’s really helpful. Unfortunately April is still a bit early for many of these.

Views of Cock’s-foot grass – tussock, shoot and ligules photographed this week. The seed head was photographed last summer.

But most importantly…

Just enjoy the Challenge, which is a celebration, and a chance to wonder at the sheer amount of nature that is out there.

I’d also like to thank all the wonderful experts who give their time to identify thousands of observations during the Challenge – you’re all ID heroes!

City Nature Challenge links

Find out if your region is taking part on the list – https://citynaturechallenge.org/city-list-2021/

Check out the City Nature Challenge FAQs.

Take part by registering (for free!) on the iNaturalist website and upload photos, or download the app – iNaturalist for Android or iNaturalist for iPhone.

Winter wanders

In the depths of a cold, damp winter, it can be difficult to muster up the effort to get outside. The lockdown exercise that was so easy on the bright, sunny May mornings is now much more of a chore. Icy roads stop me from cycling, a complaining knee has stopped me from running, and my waistband is sadly tightening as a result.

Fortunately I still have Wildflowerhour to hold me to account. Held on Twitter every Sunday evening between 8 and 9, it invites the people of ‘botanical Twitter’ (yes, that’s a thing) to share pictures of flowers they have found that week. It has to be that week – no cheating! – and it has to be a flower, but the odd fern or fungus sometimes sneaks under the radar. Plus any flowers you planted yourself – like the snowdrops from my garden in my title image – don’t count! So to take part, I HAVE to put on my boots and get outside.

The fact that there are relatively few species out means that I record small or else very common flowers, like daisies and dandelions, that I might not have bothered with previously; they now come into their own as a welcome sight. I’ve noticed that I’m more likely to find flowers in urban environments, probably because they are a degree or two warmer – and the bases of walls and lamp-posts have the added benefits of extra, erm, liquid fertiliser from the local dogs.

Lesser Celandines (Ficaria verna) have been popping up for a couple of weeks now. I wouldn’t normally expect them to be out yet, but other Wildflowerhour participants have posted several. My Mum has pointed out that the Welsh word for them, Llygad Ebrill, means ‘April Eye’ so these ones really have got going early.

Also ahead of schedule is this Three-cornered Leek (Allium triquetrum), an invasive but lovely plant with dangling white bells, which in previous years I have recorded in March and April. I photographed this one at the end of December, and the patch where I found it has now finished flowering!

You can’t go wrong with the Asteraceae (daisy family) which stay hard at work all year round. I am still seeing plenty of Groundsel (Senecio vulgaris) and Smooth Sow-thistle (Sonchus oleraceus) along the roads.

*Groundsel (Senecio vulgaris)* and *Smooth Sow-thistle (Sonchus oleraceus)*

I was delighted to find this Common Field-speedwell (Veronica persica) with fully open flowers in a patch of sunshine. It is a shy flowerer, only coming out in full sun – the rest of the time it remains tightly rolled up.

Common Field-speedwell (*Veronica persica*), flowering and rolled.

Another source of flowers that you might not normally think of – as they might not look like typical ‘flowers’ – are those of trees. Common Hazels (Corylus avellana) have two types of flower – male and female. You will easily see the male flowers, the dangling, pale yellow catkins which are lighting up many hedgerows just now. But have you ever looked really closely at the twigs to see the female flowers? I only did so quite recently, and was astonished. They are green pods bearing tiny, but incredibly bright fuchsia pink tassels. Magnified under a lens, they seem impossibly exotic for a grey British winter.

Male catkins (left) and pink female flower tufts (right) of Common Hazel, Corylus avellana.

What winter surprises can you find?

Wonderwalls

Back in Normal Times, which are now so far in the past they don’t seem normal any more, I cycled an hour each way to work, combining exercise with my commute. Working from home meant I lost part of my fitness regime, so I started cycling for its own sake, exploring the quiet routes around my neighbourhood. My penchant for spotting a beguiling leafy lane and wondering ‘where does this go?’ has resulted in a polite but firm request to get off private land (surely bikes don’t count?) and frequently getting lost (thank heavens for smartphones). It’s also led to the discovery of several plant colonies in what might seem rather peculiar places: walls.

Plants exploiting this seemingly inhospitable habitat are called ‘lithophytes’ – rock-plants. Their natural home is a cliff-face or rocky scree, but if humans obligingly provide a sheltered alternative, they will happily take advantage. While they may appear to be miraculously growing out of nothing at all, most of them do need some kind of fissure, however small, to get going. They rely on their relatives, lichens and mosses, to start this process. These pioneers of bare rock will start to dissolve the stone, creating tiny cracks, and providing the first dusting of organic matter that plants need to get their roots into. Natural erosion and weathering helps too. An old brick wall beginning to crumble, or a dry-stone wall that comes with lots of handy niches built in, provides the foothold these plants need to establish. My own town is a relatively new estate, built from neat, tightly mortared bricks, and I don’t see any wall plants there – so I was delighted to find them on my expeditions.

Wall-rue (Asplenium ruta-muraria) and Rustyback (Asplenium ceterach)

These are both little ferns, spreading through tiny wind-borne spores rather than seeds. They need damp places to establish, and the deep cracks of a stone wall seem to suit them well, while dry conditions in summer are perfect for spore distribution – Rustyback gets its name from the prolific coating of spores on its underside. The name Asplenium denotes a member of the spleenwort family, and indeed both of these ferns were once used as herbal remedies for spleen or liver disorders.

Wall pennywort or Navelwort (Umbelicus rupestris)

Mostly found in Wales and the west of England, this extraordinary-looking plant had me braking to a sudden halt when I first saw it in flower. The round, thickened leaves look to me like miniature lily-pads, but they also resemble coins – hence ‘pennywort’. The little dimple where the stalk joins the leaf leads to the name Navelwort, and indeed the Latin Umbelicus. In summer it has long spikes of greeny-white flowers – or to quote John Gerard’s rather enigmatic description, it is ‘beset with many small floures of an overworne incarnate colour’. (?!) These only add to the alien appearance, with the result being a plant that would not look out of place in an episode of Dr Who.

Wall-pepper or biting stonecrop (Sedum acre)

Sedum ‘sitting’ on the wall, hence its name

‘Sedum’ means sitting – as this plant does on top of a wall – and ‘acre’ means ‘acrid’. This in addition to its common names suggest that this edible plant is quite a piquant addition to salads. The yellow flowers are very cheerful in summer. It has another, quite extraordinary common name; ‘welcome-home-husband-though-never-so-drunk’. Perhaps this was given because, once it has colonised your walls and roofs, the plant is always there when the husband comes home, although the wife might not be.

Ivy-leaved toadflax (Cymbalaria muralis)

Ivy-leaved toadflax is native to Italy. One suggestion for its arrival here is that it hitched a lift on marble sculptures. From these civilised beginnings it appears to have scrambled up every wall in the country. The pretty purple and yellow flowers look like miniature snapdragons. They grow towards the light, but once the petals fall, the seedheads bend back towards the wall – where they are more likely to find another crack to grow in.

Tricks of the trade and a CAMazing adaptation

Growing on rocks is tough, so wall plants tend to be specialists. You can recognise this in some of their scientific names. The Latin for wall, murus, appears in muraria and muralis, while rupestris means ‘of rocks’- presumably derived from petra. They employ a number of survival tactics, most importantly various methods for surviving drought. Ferns can go dormant – the rustyback will curl up, apparently dead, but will revive in the next rainfall. Ivy-leaved toadflax has shiny, waxy leaves to help retain water, while navelwort and stonecrop are succulents, having thick, juicy leaves that act as water storage tanks.

Navelwort and stonecrop have an even cleverer trick. They are members of the Crassulaceae, a family which gives its name to a system called the Crassulacean Acid Metabolism, or CAM for short.

Every day, plants carry out the miracle of photosynthesis, in which they take in carbon dioxide and water, and, through the action of sunlight on a special enzyme, use them to create sugars and oxygen. This is the basis of ALL our food and breathable air. Please pause to consider that for a second.

Considered? Good. So, plants take in carbon dioxide from the air, and to do this, they have to open special holes, or stomata, in their leaves. But while carbon dioxide is getting IN, precious water can evaporate OUT. For plants in dry environments, this is a real problem. CAM is an ingenious answer to this eternal plant dilemma. CAM plants open their stomata and take in carbon dioxide at night, when it’s cooler and they lose far less water. They can’t photosynthesise in darkness, so they store the carbon dioxide in the form of malic acid, which builds up overnight. In the morning, once the sun rises, they close the stomata, turn the acid back into carbon dioxide, and start photosynthesising without risk of water loss. Due to the concentration of carbon dioxide in a few cells, this is also far more efficient than ‘normal’ photosynthesis. THIS IS VERY COOL.

I understand that edible CAM plants taste notably more acidic in the morning – when the acid concentration is at its highest – than in the evening, though I haven’t been brave enough to try tasting them at any time! The sap of both sedum and navelwort was once used in herbal remedies to cure skin complaints, and malic acid is still used in some skin creams and cosmetics today.

Wonderwalls indeed!

References

John Gerard – Gerard’s Herbal

Gabrielle Hatfield – Hatfield’s Herbal

Richard Mabey – Flora Britannica

Roger Phillips – Grasses, Ferns, Mosses and Lichens of Great Britain and Ireland

Well trodden ways: plants of trampled ground

According to my latest quarterly slew of wildlife magazines thumping onto the doormat, lockdown has led to people appreciating nature as never before. Deprived of gyms and high street shopping, we’ve been getting our exercise outdoors (the weather helped!) If this can lead to an increase in society’s value of green, open spaces then that can only be a good thing. I do worry though about the added pressure on some already fragile environments. The main path through my local nature reserve is packed with runners and cyclists even at 7 am, but at least it’s robust, with a gravelled surface. Where unsurfaced paths in the woods get muddy, they get wider and wider as people veer further and further away from the deeper parts, and the plants at the edge are eroded off and mushed into the slurry as a result. Regretfully, I think there is a case to be made for shutting some wild places off from humans altogether.

There are a few plants, however, that positively revel in this treatment. Nature has a specialist for everything, including being stomped on. Tough as old boots, these plants of the wayside have adapted to resist constant trampling, meaning that they can take full advantage of the spaces left by the demise of their weaker companions – and their seeds are distributed on the soles of walkers’ shoes, meaning they can colonise the next section of path.

Greater Plantain – Plantago major

The king of trample-tolerant plants, plantain leaves contain very tough, elastic fibres which resist damage. Its apparent indestructibility led to its use as a healing herb. It is included in ‘The Nine Herbs Charm’, a recipe for a salve written in Old English and found in the Lacnunga, a 10^th/11^th century herbal. Plantain is addressed as ‘wegbrade, wyrta modor’ (Waybread, mother of herbs). ‘Brade’ means ‘broad’, referring to the leaves.

Knotgrass – Polygonum aviculare

You may not easily notice the low, creeping knotgrass, spreading across the path; but if it gets into your flowerbed, you will probably never see the last of it. One of its other common names, irongrass, is testament to its indestructability – and the difficulty of removing it from where it’s not wanted. It is not a grass of course, but is related to docks. Its pinkish flowers are tiny, but quite pretty if you get very close up, and the seeds are important food for birds.

Scentless Mayweed – Tripleurospermum inodorum

Scentless Mayweed is the commonest of several plants with frondy, feathery foliage and daisy-like flowers which pop up on paths and in gateways. Chamomile is another and some gardeners create ‘chamomile lawns’ which are resistant to being gently walked on and release a sweet scent.

Pineappleweed – Matricaria discoidea

Pineappleweed is another member of the daisy family – much less showy than mayweed, but you can see that the yellow, domed flowers are similar to the centres of daisies. When crushed it exudes a pineapple scent. Originally from Asia, it has made a successful global takeover, spreading first to North America and then appearing in the UK by the late 19^th century. Spread by humans was of course the cause. The seeds of pineappleweed are easily picked up in tyre treads and shoe soles, and once it falls it appears able to take root anywhere, including roadsides and pavements.

So, do enjoy your walk, but try not to stray off the path. Only trample on the plants you know can take it!

Links

9 Herbs Charm, original text and transation by Benjamin Slade, https://heorot.dk/woden-9herbs.html

Richard Mabey’s Flora Britannica was as ever a source of wondrous and whimsical information.

Green Grow the Rushes O!

Go into a field that is prone to damp and flooding and you will see myriad spiky clumps of long, rounded leaves. These are rushes, members of the Juncus family. Growing where many grasses would give up, rushes are often overlooked. They aren’t pretty (their ‘flowers’ are boring, brown clusters), they are spiky on your bare legs and they trip you up! But rushes used to be much more highly valued – indeed, they were an essential resource. ‘Rushlights’, made from the inner pith of the leaf soaked in whatever fat or grease was available, were an alternative to expensive candles for generations. Rushes were also strewn on floors to provide a softer, sweeter surface, and woven to make baskets, chair-backs or children’s toys. They were even used to thatch roofs.

There are several species of rush growing in the UK; here are four of the most common.

Soft rush, Juncus effusus

Juncus effusus inflorescence and pith, and in the field.

The leaves of soft rush are a shiny green, and are easily compressed between the fingers. If you peel away the green outer layer, you reveal the white pith – a continuous, spongy mass, the basis of the rushlight. Having attempted to peel the rushes for photographs, I found this very fiddly. However Gilbert White, the famous naturalist and vicar of Selbourne, attested in 1775 that with practice, people got so good at it that he had seen an old blind woman peeling rushes ‘with great dispatch’. Its inflorescence, or flowerhead, is a tightly bunched bouquet of little brown florets.

Hard rush, Juncus inflexus

Hard rush, true to its name, has grey-green, ridged leaves which are highly resistant to squeezing. Its pith is ‘discontinuous’ – i.e. full of holes – so far less desirable as a rushlight. It has a looser inflorescence than soft rush, waving like a flag halfway up the stem.

Compact rush, Juncus conglomeratus

Compact rush – inflorescence, continuous pith, and in the field

Compact rush is both compact in height, being shorter than its cousins, and in its distinctive dense inflorescence, like a brown pom-pom hugging the stem. Its leaves bear deep grooves, which can be easily felt between the fingers. Its pith is similar to soft rush.

Jointed rush, Juncus articulatus

Jointed rush inflorescences and ‘articulated’ partitions

Jointed rush has almost no pith but its leaves have regular internal partitions. You can feel these if you run your fingers up the stem – little bumps or ‘joints’ at regular intervals. It has an open, floppy inflorescence at the top of the stem.

Next time you take a walk through a rushy field, see if you can spot any of these – and be thankful for electricity!

References

Image of rush field -C Michael Hogan / Field with rushes south of the N67 road, downloaded from Wikimedia Commons.

Juncus effusus pith – By Alfred [GFDL (http://www.gnu.org/copyleft/fdl.html), CC-BY-SA-3.0, from Wikimedia Commons

Account of preparation of rushlights; letter of 1 November 1775 from Gilbert White to Daines Barrington, The Natural History and Antiquities of Selborne. Available at http://www.gutenberg.org/cache/epub/1408/pg1408-images.html

Juncus inflexus pith – By Kristian Peters — Fabelfroh 12:43, 9 July 2006 (UTC) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/)%5D, from Wikimedia Commons

Juncus articulatus pith – By Stefan.lefnaer [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)%5D, from Wikimedia Commons

The Botanical Book of the Dead

One of the biggest challenges for the new botanist is remembering all those plants you’ve learned. I only know a fraction of the hundreds of plant species in the UK, and forgetting what little I know is very frustrating! Even expert botanists agree that it’s a challenge, especially getting back to surveying after the long winter break. Even as an amateur, I’ve surveyed for enough years now to be all too familiar with the scene – kneeling in a woodland glade on a sunny April morning, staring at a plant and thinking sadly, ‘Well, I definitely used to know what that is’.

Repetition is key to retention; the best way is just to get out there regularly and look at plants alongside someone who knows what they’re doing. Gradually, as you see the same plants over and over again, some of them will stick. Except this year, there is a bit of a hitch, thanks to Covid-19. My usual Wildlife Trust team hasn’t got back to surveying at all. We’ve lost the entire spring survey season and it looks as if we’ll miss most of summer as well. I’m desperately looking at plants on my daily walk or cycle ride and thinking ‘Oh help. What’s that one?’

Technology is coming to my aid. The app and website inaturalist has a brilliant algorithm that can identify an incredible range of plants, and the wonderful Twitter botany community on #wildflowerhour and #wildflowerID is there to help and explain ID for any tricky ones – bless you all. But I’m also falling back on something far more old-fashioned, with not a silicon chip in site.

It was fellow Trust volunteer and long-term botanist Suzanne who introduced me to her Book of the Dead. This was a large notebook with leaves and flowers taped to its pages, accompanied by notes of where and when they had been found, with other ID tips. Suzanne explained that the action of taking and recording a specimen could help you to remember it; sticking something in a book just might help you stick it in your brain.

Inspired by this, I started my own Book of the Dead. Below you can see some of its pages. It isn’t pretty – this is no Victorian pressed-flower album. The pages are muddy, escaped spores make dark stains and the tape has usually got stuck to me, some dead leaves and part of my lunch before I manage to wrestle it into submission. However, it’s very effective at reinforcing new knowledge, and for some specific plants it’s proved better than a field guide. In lockdown, it’s also reviving memories of cheerful surveys in good company, at the lovely reserves where I collected the samples. They feel very far away at the moment, but we’ll be out there again before too long.

Below are four sample pages from my Book of the Dead.

IMPORTANT NOTE: I only ever take samples of common plants when there are clearly lots of them about. NEVER pick flowers or other parts of rare or scarce plants. If you don’t know, leave it to grow!

Fern samples. These were taken during a guided walk on ferns. I often refer to these pages, finding them more helpful than published guide books.

2. Comparing similar plants. The left hand page has some different types of speedwell. At the top of the right hand page are the similar-looking lobed leaves of moschatel, wood anemome and sanicle, which grow in the same kind of woodland habitat and which I could easily get mixed up. Published identification guides wouldn’t put these three on the same page as they aren’t related, but here I can make a direct comparison.

3. Black medick, lesser trefoil and hop trefoil all look very similar. I have used this page to record the main differences between them.

4. Samples from a grasses training day. Robust grass seedheads are stuck in, while the notes record details about the more delicate plant parts that won’t survive this process!

Pretty parsley or killer carrot? The world of the not so humble umbels

If you have taken a suitably socially-distanced wander around the roads and lanes recently, you have probably seen the verges frothing with one of our best-known wildflowers, certainly one of the first I learned to name:cow parsley, more sweetly known as Queen Anne’s Lace. It’s a member of the Apiaceae, better known as Umbellifers because they hold their flowers in ‘umbels’ – flattened flowerheads consisting of many tiny flowers held on branched stalks, just as the fabric of an umbrella spreads over its spokes and struts.

The Umbellifers are quite a family. They provide us with vegetables – carrots, parsnips, celery – and herbs and spices to flavour them with; parsley, angelica, cumin, coriander. But not all are so benign. Some can maim, and some can kill – and the fact that they can look very alike can result in unfortunate mistakes being made. With umbellifers, as with any plant, you should follow the common sense rule: if you aren’t absolutely sure what it is, don’t touch it, and definitely don’t eat it.

With that caveat over with, here’s a look at some of the umbellifers you are likely to see when out on your government-permitted walk.

Common hedgerow umbellifers

Cow parsley (Anthriscus sylvestris)

Cow parsley is indeed edible for cows, as well as rabbits and other herbivores. It was once also a source of free playthings for children, who used the hollow stalks to make pea-shooters or whistles. It flowers from April to June, after which its role as hedgerow adornment is taken over by its slightly smaller and slenderer cousin, Upright Hedge-parsley (Torilis japonica).

Alexanders (Smyrnium olusatrum)

Alexanders flowers at the same time as Cow Parsley, but is easily distinguished by its flowers being yellowish-green rather than white. Introduced by the Romans, it has been growing wild in the UK for several hundred years. It was widely eaten as a vegetable until its relative, celery, became available, which is why it pops up on the sites of monastery kitchen gardens. It’s commonly found near the coast, but near me, it grows in abundance in certain old field hedges.

Wild Carrot (Daucus carota)

Taking the stage from midsummer, wild carrot is nothing like its cultivated cousin, apart from the smell. It won’t give you much worth eating, though the seeds can be used instead of hops to flavour beer, and have been used to some effect in treating kidney stones. Wild carrot has lovely feathery foliage, and its flowers are worth pondering. The umbels start out pink and then turn the standard white, but if you look carefully you will usually see that just one tiny flower remains a deep claret colour. As they turn to seed, the flowerheads become bowl-shaped, giving rise to one of its common names, ‘bird’s-nest’.

Hogweed (Heracleum sphondylium)

Hogweed (Heracleum sphondylium) is a no-nonsense umbellifer, a big, sturdy, hairy plant with large multi-lobed leaves. Its main flowering period is late summer, but it can be found in flower all year round. As with cow parsley, the hollow stems can be used as toys, and it can also be food for livestock. It should be treated with caution, however, as the sap from mature growing stems can cause rashes or even burns. This is because the stems are high in chemicals from a group known as furocoumarins.

The dark side of umbellifers

Many members of the Apiaceae contain furocoumarins. In low doses these may be harmless, and indeed they are found in many of the edible plants, like celery (note that they can interfere with the action of some drugs, such as statins). However, some plants contain more furocoumarins than others, and certain types are phototoxic – that is, they are harmful if combined with ultraviolet light. If splashed on the skin and exposed to daylight they cause severe irritation, rashes or even burns, and the affected area can stay sensitive to sunlight for years. Different people can also have different sensitivities to these chemicals. So, if you get sap from an umbellifer splashed on your skin, try to keep it out of the light and wash it off as soon as possible.

Some umbellifers go further and produce chemicals that will do severe damage to your insides as well as your outsides. Here are two to treat with caution.

Hemlock water dropwort (Oenanthe crocata)

I have heard of one self-taught botanist who, as a boy, collected what he thought was cow parsley to feed to his rabbit, with fatal results. His realisation that he ought to be able to tell different plants apart launched a long and highly respected career. The plant he picked was hemlock water dropwort.

Hemlock water dropwort grows in marshes, ditches and other damp places. It is recognisable – once you know what you’re looking for – by its conspicuously grooved stem and rounded, pom-pom style umbels. It smells very sweet, and looks very pretty, and it is very poisonous, thanks to the dropwort family’s namesake chemicals, oenanthotoxins. Humans have poisoned themselves with it by mistaking it for angelica or another of the edible family members, and cows have been killed by grazing on the roots – this particularly tends to happen during dry periods, when roots can become exposed in drainage ditches.

Hemlock (Conium maculatum)

Hemlock grows in large, straggly curtains over a metre high. It also contains a namesake poison, the alkaloid coniine, and is well known as the method of Socrates’ execution. Fortunately the plant is easily recognisable by its purple-spotted stems, and it has a nasty sour smell, so mostly people and animals manage not to eat it by accident.

From baby to Big Daddy

I’ll finish up with two plants you are much less likely to see, but which I can’t resist describing as they are at such ridiculous extremes.

Honewort (Trinia glauca)

Honewort. Can you spot the ant for scale?

I have enthused before about honewort, the baby of the Apiaceae family. This is a very rare plant in the UK, being found in a handful of sites in the south of England. Fortunately some of those are Avon Wildlife Trust reserves and I am lucky enough to have surveyed honewort with the AWT monitoring team. It has the usual family trait of white flowers in umbels – but in ultra-bonsai’d form. It never gets more than 20cm high, and given its usual habitat of close-cropped turf over windblown rock, it’s generally tinier than that. You have to get down on your hands and knees to see it. Another unusual trait is that it has different male and female plants (dioecious); the female plants have smaller flowers and are even harder to spot.

Giant hogweed (Heracleum mantegazzianum)

Giant hogweed is the most infamous member of the family and is officially ‘offensive’ (!) in that it’s an offence to plant it, sell it or allow it to escape, under the Wildlife and Countryside Act 1981.

A recent Metro article claims that it can be ‘easily mistaken for cow parsley’. I’ve no idea how because IT LOOKS LIKE A TRIFFID THAT MIGHT ACTUALLY EAT YOU. The leaves are up to 1.5m wide and 3m long and the whole plant can get up to 5 metres tall – possibly the largest herbaceous (non-woody) plant in the UK.

Like many of our ‘problem plants’, giant hogweed is not native to the UK, originating from Central Asia, and was introduced here by the Victorians. (It’s always the Victorians). Of course it escaped its original garden homes, and spread through the UK. Its seeds can float on water, so it’s easily transported along rivers and streams, where it can colonise the banks.

Is it really so bad? It can certainly be invasive, but the main reason for its bad rep is those furocoumarins again. The sap and bristly stem hairs contain a lot of them, and a splash of sap on the skin can cause a very, very nasty burn and a permanent scar. But if you leave it alone, and admire it from afar, it’s really a very impressive plant. And there’s enough bad stuff going on in the world just now without wasting hate on a wild flower. It’s only a big carrot, after all.

All photographs my own except for:

Hemlock stem and Hemlock flowers – MPF / CC BY-SA (https://creativecommons.org/licenses/by-sa/3.0)

Flowering giant hogweed – Meneerke bloem / CC BY-SA (https://creativecommons.org/licenses/by-sa/3.0)

Botany in your back garden – the BSBI Garden Wildflower Hunt

The Botanical Society of Britain and Ireland (BSBI) have just launched an initiative ideally suited to the constricted circumstances in which we find ourselves: a Garden Wildflower Hunt. They want to understand how wild plants are distributed in our gardens, and how they are spreading – or not – in the face of various challenges such as climate change or changing gardening practices.

Anyone with a garden, however small, can take part, and it’s a great way to discover what’s on your patch if you aren’t already in the habit of taking a close look. Some people may view the wildflowers in their gardens as ‘weeds’, but they can be very valuable as a habitat or food plant to wildlife, so it’s worth leaving some to flourish… plus it’s less work!

If you want to take part then visit https://gardenwildflowerhunt.org/app/list/survey/welcome. You will need to take photographs. You can enter records online, or if you have a smartphone then it’s probably best to use it to visit the site and download the app – you can then take photographs on your phone and they’ll be entered directly into your records.

A lot of the wildflowers in my garden were in leaf but not yet flowering, and so it was helpful that I was already familiar with them as I knew what they were going to be. If you don’t know what you’re looking at, don’t worry; as long as the photograph is clear there will, hopefully, be a nice botanist on the other end who will be able to work it out! However I can also highly recommend the inaturalist website and app, which has a brilliant algorithm for identifying species from photographs.

Here are some of the wildflowers I found in my own garden.

Three Speedwells

I was delighted to find three varieties of Speedwell in my garden. There are several types of native speedwell, in various shades of blue and lilac. As they are common wayside flowers their name may come from ‘speeding the traveller well’ on his way. The Common Field-speedwell is the largest of these three, though still small, with flowers less than 1cm across, but it is shy and tends to keep its flowers furled up – I had to wait until the sun was right on it before it came out to say hello. The others have really tiny flowers at about 2mm across. I was lucky to spot the thyme-leaved speedwell in my front lawn, but ivy-leaved speedwell is EVERYWHERE in my garden – all up the path, taking over pots, and generally enjoying itself.

Dandelions and their allies

The dandelion family or Asteraceae is huge and successful, thanks to its members’ ability to colonise any patch of ground with casual efficiency. The most recognizable is the dandelion itself – its name comes from the French for lion’s tooth, dent-de-lion, after the jagged shape of its leaves. Even this common flower that most of us simply think of as ‘dandelion’ comes in about 200 micro-species – the mere thought of sorting these out is enough to drive me to binge-finish the Easter egg.

Nowadays thought of as a weed, dandelions were once prized enough for people to be paid to dig them up, thanks to the use of the leaves as a diuretic, the flowers for dandelion wine, and the roots in dandelion-and-burdock drink. While they are not so prized by humans today, they are an invaluable source of nectar for insects, which is my excuse for not getting rid of them.

I was able to easily recognise dandelions and their cousin groundsel in my lawn, as they were in flower. But I also photographed some leaves, growing in the flat rosette form typical of the Asteraceae (this contributes to their success by helping them evade the lawnmower). What were they? This is where it comes in handy to keep a year-round eye on your patch – and take photographs. I know what other flowers I have seen growing there and consulting my picture library helped me to sort them out. These are the leaves I photographed this week, combined with the flowers identified last summer.

Cat’s-ear and mouse-ear hawkweed are both named after their softly hairy leaves; cat’s-ear leaves have triangular toothed edges, while mouse-ear hawkweed leaves are rounded. Cat’s-ear also has dark spots (bracts) up the stem, and liquorice-coloured stripes on the back of the petals, while mouse-ear hawkweed flowers are a paler lemon yellow with red candy strips.

Bristly oxtongue is actually identifiable from the leaves alone as nothing else is that pimply.

And the rest…

I was similarly able to identify another mouse-ear, Common Mouse-ear (this is why common names can be confusing!) – but this one, Cerastium fontanum, is a chickweed, from the Campion family. Its tiny, fuzzy leaves really are like a mouse’s ears. It will have little star-like white flowers, emerging in late spring.

I mentioned Lesser Celandine (Ficaria verna) as a woodland plant in my last post, but the cheerful thug has also taken over my woodland-style garden, without being invited. I prefer it to bare ground.

Another favourite in the garden is a member of the Geranium family, Herb Robert (Geranium robertianum). I let it ramble where it likes, but it’s easily pulled up if you don’t want it.

Wavy bitter-cress (Cardamine flexuosa) likes the area around the compost bins. I can tell it’s wavy, not hairy bitter-cress as I got a good enough photo to see that it had 6 stamens (see Wee white cabbages).

Finally I was delighted to spot the leaves of a tiny plant whose common and scientific names are both charmingly eccentric; Kickxia elatine – Sharp-leaved Fluellen. I first spotted it flowering in my garden last August and am very glad to see that those arrow-shaped leaves are back.

Join in!

Why not step out into your own garden, put down the weedkiller, and go on your own wildflower hunt? If you send your records to the BSBI, you’ll be contributing to a valuable citizen science project.

If you find you get the plant recording bug, and you are happy using a smartphone app or with uploading pictures to a website, then I can also highly recommend the City Nature Challenge which takes place next weekend, 24-27 April. Using the excellent inaturalist website, this global initiative encourages people to identify as much wildlife (plant or animal) as they can over four days, in their local city and its environs. In previous years this has been a competition, but in view of the current Unprecedented Circumstances they are making 2020 a celebration instead – an opportunity to rejoice in the nature that is still out there waiting for us, including in your back garden.

So get out there, get plant-hunting, and stay safe.