Wednesday Weed – Himalayan Balsam

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…..

Himalayan balsam (Impatiens glandulifera)

Dear readers, I am glad to report that I have not yet seen Himalayan Balsam  in my East Finchley ‘territory’, but when I spotted it on a trip to see my parents last week I realised that I wanted  to write about it. It is a member of the busy lizzie family, but if you look at it through narrowed eyes it looks much like one of those exotic orchids that you can buy in Marks and Spencer. It’s also known as Policeman’s Helmet, for its hat-like shape.

It’s not hard to see why Himalayan balsam was introduced to the UK – it is a most attractive decorative plant, and comes in a wide variety of colours, from palest blush pink through princess-skirt pink right up to intense cerise. Is there something a little sinister about the buds though? The stems remind me of bony hands.

The plant is said to be sweet-smelling (though I would have had to wade through a drainage ditch to get to them, so I’ll take my plant guide’s word for it). It is certainly extremely popular with bees, though as the Non-native Species Secretariat points out, this could be a problem in itself, as, with fewer bees about, native plants might not receive so many visits from pollinators.. It is common throughout the UK – when I look at my Field Guide to Invasive Plants and Animals in Britain, all but the most mountainous areas of Wales, Scotland and Northern Ireland are a solid red colour, indicating the presence of the plant. It is particularly implicated, according to the book, in replacing plants such as the tansy, which is the only food of the endangered tansy beetle.

Photo One (Tansy) - CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=171549

Tansy (Tanacetum vulgare)

Photo Two (Tansy Beetle) - By Geoff Oxford - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=13290111

Tansy Beetle (Chrysolina graminis)

Himalayan balsam arrived in the UK in 1839, part of a trifecta of invasive plants that included Japanese Knotweed and Giant Hogweed. These three were selected because of their ‘splendid invasiveness’ (which meant they were cheap) and their ‘herculean proportions’. Ten years after being introduced, Himalayan balsam was already galloping across the country like a runaway horse.  The plant is an annual, but its seeds are fired when the seed capsules are triggered by touch (incidentally, the plant’s hair-trigger is the reason for the genus name Impatiens, meaning ‘impatient’).Up to 800 seeds are released with every explosion, and Richard Mabey reports that, in a competition held by schoolchildren to see how far the seeds would go, the record was 12 metres. Mabey also mentions that children know that if the seedpods are held in a closed hand, the ‘explosions’ feel as if you are holding a squirming insect. What fun!

The seeds are unaffected by water and so, much as plants like Oxford ragwort and buddleia were spread along the railways by the draughts created by passing trains, so Himalayan balsam is spread along rivers and streams and canals by the currents.

For a while, there was a programme of ‘Balsam bashing’ which attempted to control the plant by battering it to the ground. Alas, this was not probably the best way of dealing with an adversary that fires its seeds on contact, and the eventual conclusion was that cutting and removing the plant made more sense.

Why, you might ask, has Himalayan balsam been so successful, in such a short period of time? It can’t all be down to having artillery as a seed dispersal mechanism. One theory is that the plant uses something called allelopathy, which means that it secretes a toxin that negatively affects neighbouring plants. Bruising the plant and leaving it to rot means that these chemicals are concentrated, another reason why Balsam bashing was a sub-optimal control method.

If we look at the plant in context, however, another reason hoves into view. Himalayan balsam prefers waterways where there is eutrophication, or a high level of nutrients, usually phosphate-heavy fertilizers, from farmers’ fields. Our native plants generally prefer cleaner water. So all we have to do is clean up our waterways. Simple. There is also a school of thought that suggests that sometimes Himalayan balsam is the only thing that will grow along our most polluted canals and streams, and that it is better than no plants at all. I suspect that the only way to view the situation is pragmatically, on a case-by-case basis.

Pale pink Himalayan Balsam

In Wiesbaden in Germany, an attempt has been made to make the plant pay for its own iradication. After visiting the website of the Bionic Control of Invasive Plant Species, I have discovered that they are making jam from the flowers of Himalayan balsam, along with a relish and a jam from Japanese knotweed, and jams from stinging nettles and dandelions. Good luck to them, I say.

One feature of recent plant introductions is that they have few ‘enemies’, because they’ve left them all behind in their original homes – in fact, in Clive Stace’s magisterial ‘Alien Plants’ (New Naturalist series) he describes the situation of recently arrived non-native plants as being ‘enemy release’. Often, it takes a long time for native generalist insects and fungi to start recognising a newIy arrived plant as a food source, and any specialised ‘enemies’ often don’t make the journey with the plant.In the UK, a rust fungus has been released to control the plant, which fills me with some trepidation: we have a native Impatiens, called the touch-me-not balsam, which is nationally scarce (confined to parts of Wales). Let’s keep our fingers crossed that the paths of these two plants don’t cross.

Photo Three (Touch-me-not balsam) - By MdE (page at dewiki | page at commons) (own photo) [CC BY-SA 3.0 de (http://creativecommons.org/licenses/by-sa/3.0/de/deed.en)], via Wikimedia Commons

Touch-me-not balsam (Impatiens nolitangere)

Medicinally, Himalayan balsam is one of the five plants used in  Rescue Remedy, one of the Bach flower essences that is used specifically for anxiety. In the village of Kishtar, described as being in ‘the lap of the Himalayas’, the roots and leaves are crushed and applied to the forehead, hands and feet to produce a cooling effect and, interestingly, a decoction of the leaves is also used for anxiety. The flowers are used as a treatment for snakebite.

I have a positive cornucopia of riches for you on the poetry front this week. As a starter, here is ‘Wild Balsam’, one of ‘four Flower Remedies’ by Katherine Towers, a poet that I hadn’t come across before. To read the rest of them, go here.

Wild Balsam

a remedy for impatience

I gave short shrift
to motherhood and flung
my children from me.
Who’d have those tiny shoots
under their feet all day?

I want to think and work.
I want to make of my hamstrung life
a brilliant fever.

Then, there is a poem by the Irish poet Tara Bergin, called ‘Himalayan Balsam for a Soldier’. I generally don’t cut and paste the work of living poets (because after all, this is how they earn their living) but you can hear the poet read her work, and see the poem here.

And finally, here is ‘Himalayan Balsam‘, by Anne Stevenson. It’s a poem of many twists and turns, but don’t let that put you off. It is apparently an AS level text, so there is a handy presentation on Youtube explaining it to death.

So, what a problematic plant Himalayan balsam is. Beautiful and invasive, nectar-rich and explosive, a beautifier of polluted riversides and a smotherer of native plants, it is impossible (for me at least) to come to a definitive conclusion about it. Hero or villain, I have no idea without knowing the context, and will be full of doubt even then. As with most ‘alien’ organisms, it’s our fault that it’s here in the first place, so it seems a little churlish to be quite so hostile. On the other hand, we are losing biodiversity hand over fist. I suspect that, as climate change continues to bite and urban areas continue to grow, we will need to be both humble and intelligent in our relationship with the natural world. However, as I write this I note that some chaps in Florida are actually firing their guns into the approaching hurricane, although whether out of frustration or some atavistic belief that bullets will overpower Mother Nature I have no idea. It seems we have some way to go before that humble and intelligent attitude prevails, but I continue to live in hope.

Photo Credits

Photo One (Tansy) – CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=171549

Photo Two (Tansy Beetle) – By Geoff Oxford – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=13290111

Photo Three (Touch-me-not balsam) – By MdE (page at dewiki | page at commons) (own photo) [CC BY-SA 3.0 de (http://creativecommons.org/licenses/by-sa/3.0/de/deed.en)], via Wikimedia Commons

 

9 thoughts on “Wednesday Weed – Himalayan Balsam

  1. Rachael

    So familiar with this flower but had no idea it had been introduced. The forget-me-not impatiens is quite beautiful though. My daughter is an ecologist and is very uncompromising about invasive species. Recently at Lopham and Redgrave Fen (the source of the River Waveney) near my home in East Anglia, they have discovered a thoroughly dangerous invasive plant from (probably the Far East) which I cannot name and have not heard of – but the botanists seem terrified of it…

    Reply
  2. Veronica Cooke

    It’s hard to know what to do for the best . There were signs everywhere in Ireland telling people NOT to cut down the Japanese Knotweed as it would only spread further.

    There are concerns in Bedfordshire about the amounts of Comfrey along the River Ivel but it is so pretty, as is the Russian Comfrey.

    Reply

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