invasive species

THE PALM TREES ARE DYING

Sori, 27 April 2021

There is a walk which my wife and I take in Liguria (calling it a hike would be a bit of a stretch), which brings us by easy stages to mid level on the hills dropping into the sea, leading us eventually to the small village of San Bernardo perched atop the old fishing port of Bogliasco, from where we can walk down to Bogliasco itself and catch a bus home (after, perhaps, an ice cream to reward us for the walking).

On the way, we pass a wide terrace, which stands out from the surrounding olive terraces and vegetable patches for the simple reason that it is terribly bare. The little grass it has is clipped to within an inch – what am I saying, a centimetre – of its life. This bareness is due to the terrace’s hosting a number of ruminants – a couple of donkeys and three-four sheep – which graze voraciously on any blade of grass that dares to raise its head.

Until a year or so ago, the terrace also used to host half a dozen magnificent palm trees – very old Canary Island date palms judging by their height and girth. Two years ago, we noticed a sign which proudly proclaimed that the palm trees were part of some EU-funded project, leading us to make cynical comments about the wasteful use of EU largesse. Last year, the palm trees were gone; the ruminants had the terrace to themselves. After more cynical comments about wastage of public monies, we began to wonder.

Liguria, like most Italian regions by the sea, has a large population of palm trees. The most common palm tree by far is the Canary Island date palm, and any self-respecting seaside resort will have at least one avenue lined with them, like this one in Taggia, in Liguria.

Many gardens in Liguria, both public and private, will also boast a palm tree or two. Other than the Canary Island date palm, it’s possible to spot, over a garden wall or tucked away in the corner of a park, a whole slew of different palm species: the true date palm, the Chinese windmill palm, the California fan palm, the Mexican fan palm, the Chilean wine palm, and more.

Now, the fact is that in the last year or so during our walks and hikes in Liguria we have been noticing many dead palm trees, either with their fronds dried up and drooping piteously, or with the fronds completely amputated leaving behind a forlorn blackened trunk.

A quick zip around the Internet has shown us that this Great Die-Off of Ligurian palm trees that we have been witnessing is due to this critter.

This is Rhynchophorus ferrugineus, known in English as the red palm weevil. It’s really a very pretty beetle, one which I would be proud to have pinned to the board of a beetles collection if I had such a thing.

But this pretty, pretty beetle has the unfortunate habit of laying its eggs at the base of palm tree fronds, from which larvae hatch, which then burrow down into the trunk to the root of the fronds and live off their lymph, killing them off in the process. The larvae pupate inside the trunks, and when they have metamorphosed into beetles, they crawl out and fly off to find mates and new palm trees to attack. This attack on the fronds is deadly because palm trees, unlike true trees, die when their crown of leaves are killed or are chopped off.

This beetle is originally from tropical Asia, where it attacks many species of palms. But the active international trade in palm trees has brought it to Italy, where it has been overjoyed to find a host of new palm trees to attack. Unfortunately for the palm trees, our beetle friend is not at all finicky about what palm trees it attacks. And it seems to have no complaints about the Italian climate either.

It’s the same old story of invasive species, a topic I’ve covered several times in these posts: the water hyacinth, the prickly pear, the Himalayan balsam, the Jerusalem artichoke, among others. I’m beginning to sound like a broken record, repeating myself over and over again (as I write this, it saddens me to think that only people over the age of 60 will know what I mean, because they might well have owned a vinyl record in their youth and seen how a scratch can lead to the needle jumping backwards and repeating the same piece of music over and over. But I digress.)

Of course, it’s not just Italy which has been attacked by this plague of red palm weevils. Everywhere along the southern rim of Europe, where the climate is mild enough to allow palms to grow, the beetle has arrived and is decimating palm populations. It’s also arrived in the Middle East and North Africa and is decimating their date palm groves.

In this case, there are large, and growing, economic costs attached to this plague – in Italy, palms are merely for show. In fact, I had come across anguished talk of this beetle a year or so ago, when doing some research on date palms for a project I’m involved with in Egypt (the largest producer of dates in the world, in case anyone is interested). It is only now that I have made the connection between the holocaust of palms in Italy and this other massacre of palms in North Africa.

A sighting of the beetle in California was reported back in 2010, but it turned out to be a false alarm. It’s only a matter of time, though, before the beetle arrives in the US, and many of those tall, thin, graceful palm trees my wife and I saw in LA will start dying.

And no other corner of the world where palm trees grow will be spared the red palm weevil’s scourge. Eventually, the pretty red beetle will arrive. We simply live in a world which is far too open to trade; if we and our goods move all around the world so will other species, some of which will turn out to be invasive in their new homes. Simple as that.

As if all this is not depressing enough, Italy’s palm trees are under further attack from another invasive species, a moth this time, which hails from Uruguay and central Argentina. Its formal name is Paysandisia archon, but it’s known in English as the palm moth or palm borer. It too is quite a handsome species.

It attacks palms in more or less the same way as the red palm weevil: it lays its eggs at the base of the palm fronds, the grubs once hatched burrow into the trunk to the root of the fronds, and then they proceed to suck the life out of the fronds. “Luckily” (if that term has any meaning here), this moth has a rather long life cycle, so it’s taking longer to spread through Italy’s palm populations than the red palm weevil (and so is getting less press). But it is spreading, under the radar. Like the red palm weevil, its tastes in palms are quite catholic, so none of the palm species in Italy are spared its attentions.

Of course, one could shrug one’s shoulders and point out that this beetle is wiping out plants that are not themselves natural to Italy but were brought here from somewhere else – a punishment for an earlier disregard of Nature’s ecosystems. Unfortunately, though, the beetle also seems to attack Italy’s one and only endemic species of palm, the dwarf fan palm.

As the name suggests and the photo shows, it’s a bit of a runt of a palm. It doesn’t grow more than 2 metres high, and it grows in clumps, so you can’t use it to line a stately avenue of some seaside resort. But it is actually from this part of the world, and it does have its niche and role to play in Italy’s ecosystems. Right now, the red palm weevil seems to prefer the other species of palm available to it in Italy, so it only occasionally attacks the dwarf fan palm. But imagine what will happen once the weevil has killed off most of the other types of palms around: very sensibly, it will turn to the next best thing to keep going, at which point the dwarf fan palm’s days will be numbered – if it hasn’t already disappeared, that is; contrary to the red palm weevil, the palm moth is very partial to the poor little Italian palm.

I’d like to end this post on a somewhat positive note, but right now it looks like we are losing the battle against weevil and moth. The classic modern response of spraying everything in sight with chemical insecticide is not only dangerous but it’s also not clear how well it works. And on top of that, it appears that the weevil at least is becoming resistant to chemical insecticides. Maybe pheromone traps could work. But maybe not. What I’m really nervous about is that some bright spark will go to tropical Asia (for the weevil) or Uruguay and central Argentina (for the moth) and bring back one of these pests’ natural predators, that the predators will be set free to attack weevil and moth, and that they will promptly attack some other easier target they find, thus becoming an invasive species in their own right – this is not science fiction, it’s happened before.

The best thing is just leave species where they are. We all have perfectly lovely local species. Let’s make our surroundings lovely with them and not with species we have brought from some other corner of the globe.

JASMINE

Sori, 6 June 2020

All the walks my wife and I do around Lake Como (and now Lake Maggiore, to change a bit) start in an urban setting. We take trains, or buses, or boats, to get to our starting points and we are perforce dropped off in small towns or villages. In the last couple of weeks, as we have walked up through the back roads of these towns or villages to get to the woods and meadows above them, we have noticed a marvelous thing: whole walls of the sweetest smelling jasmine.

This person has even made a tunnel covered in jasmine (I’m guessing it’s the garage).

The scent of so much jasmine has quite gone to my head and my fingers have automatically begun doing a little research on the flower.

Truth to tell, I already did a little research on jasmine for an earlier post, when I researched the only perfume of my wife’s which I have ever liked: Chance Eau Fraîche, by Chanel. One of its ingredients is jasmine oil.

As I noted in that post, there are a large number of different species of jasmine. Some 200 have been catalogued, and who knows how many more are out there waiting to be discovered. My guess, though, is that those walls of jasmine which we have been passing are Jasminum officinale, the common, or white, or summer, or poet’s jasmine (and that’s just the English names).

The logic for my choice is simple: it’s the most common jasmine in Europe.

But it’s not native to Europe. In fact, there is only one species of jasmine which is native to Europe, and only the Mediterranean part of Europe at that, the common yellow jasmine.

Even in this case it’s difficult to say it’s a European flower. Its range stretches all the way to northern Iran.

The biggest “hotspot” of jasmine species is actually in South and Southeast Asia, although the west of China, especially Yunnan, hosts quite a few species. A number of species are present in Central Asia, but I suspect they may have been carried there from the Indian subcontinent. Australia is home to a few species, I suppose as a southward extension of their presence in Southeast Asia. And then there’s a good dozen species in Africa, especially southern Africa. To complete this world tour, no jasmine species are native to the Americas, alas.

If the jasmine my wife and I are seeing is not native to Europe, how did it get here? It seems that common jasmine, along with a couple of other jasmine species – sambac (or Arabian) jasmine, and Spanish (or Royal, or Catalan) jasmine – originally entered Europe via Sicily and Spain, when these were Arabian kingdoms: common and sambac jasmines through Sicily, and Spanish jasmine through (appropriately enough) Spain. Since I inserted a picture of the common jasmine earlier, I feel I owe it to these two other species to insert a picture of them too:
sambac jasmine

Spanish jasmine

But none of these jasmines were native to the Arabian-dominated lands either. The Arabs had discovered them even further to the east and had brought the flowers back to their homelands. They brought common jasmine back from Persia after they conquered it (a similar post-conquest westward transfer occurred with the lilac, as I narrated in an earlier post). In fact, the European name “jasmine” is a corruption of the flower’s Arabic name, which is itself a corruption of the Persian name for the flower, Yasameen, which means “gift from God” (such poets, the Persians!). And it’s possible that the Persians had come across the flower further east still. As for sambac and Spanish jasmines, it seems that trade, not conquest, brought them westwards, in the holds of the ships of Arab traders doing business with the Indian subcontinent.

Jasmines didn’t just ride westwards on trade routes. Common jasmine and sambac jasmine also rode on them out to the east, into China (another result of the ancient trade routes across the Eurasian continent – the “Silk Roads” – about which I’ve written previously). Here, too, the Chinese adopted the Persian name: Yeh-hsi-ming.

It’s interesting that the Chinese felt the need to import jasmines, given that they had quite a few of their own. Perhaps it was the pure white colour of these imported jasmines which attracted the Chinese – many of their jasmines are yellow as far as I can tell; I throw in a photo of one of the more common Chinese jasmines, winter jasmine.

By the way, it’s called winter jasmine because it actually flowers from November to March. In fact, its Chinese name, Yingchun, means “the flower that welcomes Spring” (the Chinese, too, can be quite poetic). This quirk has meant that winter jasmine has now also been carried off to many a corner of the world.

But coming back to the jasmines imported into China, no doubt their heady scent helped too; perhaps they had a stronger scent than the native species. Or perhaps it was these jasmines’ close links with Buddhist ritual (something which the early Indian Buddhists had no doubt picked up from the Hindus). Anyone who has been to a Buddhist (or Hindu) temple in South and South-East Asia will have noticed the liberal use they make of jasmine flowers.

By this reasoning, the use of these jasmines entered into China along with Buddhism, something else which was transported along trade routes (I have written earlier about a slightly different botanical story, the cooption by Chinese Buddhists of the ginkgo tree as a replacement for the bo-tree tree so beloved of South Asian Buddhists).

No doubt the Arabs were attracted by the colour of the jasmines (white seems to symbolise purity in so many cultures). But they were assuredly also attracted by their scent (which, I have to say, is indeed sublime). The name “sambac” points to this. It is a corruption of the Medieval Arabic term “zanbaq”, which means jasmine oil. As attested by the perfume Chance Eau Fraîche, which I mentioned earlier, the modern thirst for jasmine oil in perfumery is as great as it was in the Arabian kingdoms – actually far greater, since there are so many billions more of us on this planet now. Here is a field of jasmine flowers in Grasse, in the south of France, waiting for their oils to be extracted (a field owned, by the way, by Chanel).

But there is so little oil in each flower! As many as 8,000 flowers will have perished to produce this little, 1ml vial of jasmine oil (jasmine absolute, in the jargon of perfumery).

Perhaps the way the Chinese use jasmine to scent tea is a little more “humane”. I watched a no-nonsense Chinese video on the making of jasmine tea. Cutting out all the marketing bla-bla, they mix together about an equal measure of tea (usually green tea) and jasmine buds (common or sambac), they let the mixture sit for a while so that the tea leaves get impregnated with the jasmine’s scent, and then they dry it. The result looks something like this.

In truth, I’m not a great fan of jasmine tea. I like the scent of the flower on the air, but the scent of it in tea I find rather sickly. But perhaps this is because I have never had a really high-quality jasmine tea. I am ready to be pleasantly surprised one day.

Is it possible that such lovely flowers with such a delightful scent could have an evil side? Alas, it is possible: some species of jasmine have been declared invasive species in a couple of countries and are subject to eradication programmes. It is not the fault of the jasmines. It is our desire to fill our gardens with foreign flowers that is to blame. Take Brazilian jasmine, a lovely member of the family.

For starters, it’s not Brazilian at all. It’s one of the African jasmines, no doubt taken to Brazil from one of Portugal’s African colonies (remember that the Americas have no native jasmines; perhaps a colonial administrator wanted to enliven his garden in Brazil). In the 1920s, the “Brazilian” jasmine was imported into Florida. Initially, it was planted in people’s gardens, but inevitably – as I’ve recounted in other posts in the case of other invasive species – the “Brazilian” jasmine “jumped over” the garden fence and began to spread. It has now invaded intact, undisturbed hardwood forests in the south of Florida, where it can climb high into the tree canopy, completely enshrouding native vegetation and reducing native plant diversity. Here is a picture of this jasmine at work in the forests of Florida.

I was thinking about this this afternoon as my wife and I were walking high up in the hills. We were surrounded by beautiful wild flowers of all descriptions. Why do gardeners have to fill their gardens with foreign flowers when there are so many beautiful ones right on their doorstep? Another mystery to be solved one day.

Well, the evening is drawing in. It’s time for me to get ready to test something. I’ve read that the jasmine flower opens at night, so the scent is most powerful then. I shall persuade my wife to accompany me on a hunt for a wall – or just a modest bush – of jasmine, to see if this is true. I shall report back.

JERUSALEM ARTICHOKES

Milan, 18 November 2019

A few days ago, my wife entered a greengrocer’s to get some fruit and came out with fruit but also with a gleam in her eye. “I have bought some Jerusalem artichokes”, she announced, and I was delighted to hear it.

It was a University flatmate who many, many (many …) years ago introduced us to this tuber. One evening, it must have been about this time of the year, he appeared in the kitchen with these strange-looking things.

As we looked at them curiously, he asked us if we had ever tried them. When we confessed that we had not, he promised us a plateful. He was as good as his word. I cannot remember now how he cooked them – more on this later – but it allowed us to appreciate that delicate artichoke taste which is the hallmark of this tuber.

Its name in English recognizes this gustatory affinity to the artichoke. And it is that artichoke taste which drew me to this lumpy, knobbly little tuber; as I have written in a previous post, I am very partial to artichokes.

Not that we’ve eaten Jerusalem artichokes all that often since that first tasting 40-plus years ago. It is one of the few foodstuffs that is still only found seasonally – it’s available from late Autumn to late Winter, and very difficult to keep once out of the earth – so unless you maintain a sharp lookout, you’re liable to miss it. Because of that, and because, frankly, of a bad press – it has a reputation of being something you feed to animals and only eat if you’re literally starving – it’s not grown in large quantities and supermarkets rarely stock it. Once, I bought a whole load of ginger because I thought they were Jerusalem artichokes. They really do look quite similar, as I think this photo shows; the resemblance between the two has often been noted.

I cannot remember where it was that I bought this ginger, but it must have been somewhere where I couldn’t read the labels – Thailand, maybe? I also cannot remember what we did with all the ginger: probably, after a few half-hearted attempts to drink tea with a lot of ginger in it, we threw it away.

I must confess to also rather liking the name, which I find satisfyingly quirky. I initially thought that the “Jerusalem” part of the name indicated a Levantine origin for the tuber; maybe, I romantically mused, it was a foodstuff brought to Europe by returning Crusaders. But no, I discovered, North America is its place of origin. It is actually the tuber to a rather lovely flower, the Helianthus tuberosus.

It is part of the Great Columbian Exchange, that massive intercontinental move of plants and animals (and diseases … and people) which took place after we Europeans discovered the Americas: plants and animals mostly travelling from the Americas to Europe and the rest of the world, and vice versa for diseases and people. I’ve written an earlier post about a minor representative of this exchange, the prickly pear. The Jerusalem artichoke is another minor representative. It is the relative of a much more important representative, also an emigrant from North America, the common sunflower, planted in vast quantities for its oil-bearing seeds.

The French explorers of North America seem to have been the first Europeans to report on this tuber, and French colonists the first to send exemplars back to Europe. Samuel de Champlain, the explorer of the Saint Lawrence River and the Great Lakes, first came across it on Cape Cod. As related on the US National Park Service website, “after rounding the headlands of Cape Cod in 1605, the French explorers sailed south along the ocean side of the outer Cape. Avoiding shoals and sandbanks, they managed to enter the first embayment they encountered. They called the place Malle Barre and left the ship to go onshore to inspect the Native American settlement. Champlain described the scene:

Before reaching their wigwams we entered a field planted with Indian corn … The corn was in flower and some five and a half feet in height. There was some less advanced, which they sow later. We saw an abundance of Brazilian beans, many edible squashes of various sizes, tobacco, and roots which they cultivate, the latter having the taste of artichoke. The woods are full of oaks, nut-trees, and very fine cypresses, which are of reddish colour and have a very pleasant smell. There were also several fields not cultivated, for the reason that the Indians let them lie fallow … Their wigwams are round, and covered with heavy thatch made of reeds. In the middle of the roof is an opening, about a foot and a half wide, through which issues the smoke of their fire.”

Champlain helpfully included a map of the embayment in his printed report.

Another Frenchman, Marc Lescarbot, met Champlain soon after this in Port-Royal, a new settlement on the coast of what is now Nova Scotia. I throw in here a map of Port-Royal which Lescarbot included in the book he wrote some years later.

Among other things, Champlain introduced him to the tuber. Lescarbot described it as follows: “a sort of root, as big as a beet or truffle, tasting rather like chard but more agreeable”. Chard is a vegetable which I’m fond of, fond enough to have written a post about it a little while back. Lescarbot was onto something, I think: the two share a similarly delicate taste. Nevertheless, in the end I would plump for the artichoke connection, so Jerusalem artichoke it should be, not Jerusalem chard.

Europeans were responsible for the global redistribution of the Jerusalem artichoke, but in truth humans had already started to move the plant out of its natural range before Europeans discovered the Americas. When Champlain, Lescarbot, and all the other anonymous European colonists came across the native plantations of the Jerusalem artichoke on the East coast, it looked to them like the plant had always been there. But actually that was not so. The plant’s natural range is somewhere in central North America, straddling the modern US-Canada border. However, the American Indians, recognizing the tuber’s value as a foodstuff, and especially its availability during the winter months when other food is often scarce, had centuries earlier carried it out of its natural range, all the way to the east and west coasts of North America, and down south into Mexico too.

Fascinating stuff, but none of it explains that “Jerusalem” bit of the name. Unfortunately, the chroniclers of the 17th century – the time when the Jerusalem artichoke arrived in Europe and was diffusing across the Continent – were more interested in the Great Men (and possibly Great Women) as well as the Great Events of their time rather than in the names being given to new vegetables. So it has been left to modern historians and etymologists to make some educated guesses. I give two of these guesses here, the two that seem to me the most likely – or perhaps the least unlikely. The first guess has it that the tuber made its way to Rome, as a foodstuff which had miraculously saved the French (Catholic) colonists of North America from starvation. It was planted in the Vatican gardens, whose gardeners gave the plant the name girasole articiocco – “girasole” being the Italian name for the sunflower (readers will recall that the plant is a cousin to the sunflower). The usual mangling of foreign words in British mouths meant that girasole articiocco became Jerusalem artichoke. This is quite neat and is the guess I would normally lay my money on, but I can’t explain to myself how Protestant Britain would have picked up a name being bandied about in the Catholic Vatican. The second guess has it that the tuber originally entered the UK from the Netherlands and more specifically from the town of Terneuzen (the Dutch botanist Petrus Hondius, who lived there, reported in the early 1600s on having successfully planted a shriveled tuber which he had received, no doubt from Dutch colonists in North America). In British mouths, Terneuzen artisjokken got mangled into Jerusalem artichokes. Trade between the two countries was brisk, so a transfer such as this of a new foodstuff sounds quite reasonable to me. But a mangling of Terneuzen into Jerusalem seems a bit of a stretch.

One of the rare places where my wife and I came across the Jerusalem artichoke was in Paris. The French name for the tuber is equally quirky: topinambour. Here again the mists of time have veiled over the origin of the name. The best guess is that the tuber began to appear on Parisian plates at around the time that a delegation of three Amerindians from the Tupinambá tribe, which had settled on the Brazilian coastline, were paraded before King Louis XIII and his court in the Tuileries (three others had died en route). They were sent there by some missionaries, who were competing with the Portuguese for the souls of the local “savages”. No doubt the idea was to get the king interested in defending French interests in Brazil. I’m not sure they succeeded in that, but the Tupinambá created a sensation. One of the missionaries commented enthusiastically: “Who would have thought that Paris, used to the strange and the exotic, would go so wild over these Indians?”. After being paraded before the king and his court, no doubt in their “savage” state, the three Tupinambá were taken off to a church, baptized, and dressed in more “civilized” garb.

Parisians, being vague about the geography of this New World that was being discovered before their very eyes but knowing that the tuber came from somewhere over there, simply decided that the Topinambá had brought the tuber with them and began to call it the topinambour.

Helianthus tuberosus grows extremely well in Europe, it is very easy to grow, and as I said earlier its tuber is available in the winter months when other foods can be scarce. As a result, the plant’s popularity grew, especially in France, where it saw its heyday in the 18th Century. Not only were people eating it, but it was given as feed to livestock. It was so widespread in France that one of the days in the Revolutionary calendar – the thirteenth day in the month of Brumaire, to be precise – was dedicated to it. But by then, its days were numbered. The potato (another representative of the Great Columbian Exchange), after facing a century or so of hostility in France, finally won wide acceptance. It eventually completely eclipsed the topinambour.

Which is sad really, because the Jerusalem artichoke/topinambour is really quite good to eat. I personally prefer the tubers steamed (they can be boiled, too, but they risk crumbling in the water).

There’s Jerusalem artichoke soup, too, which I have yet to try.

Then they can be roasted

fried

or prepared in just about any other way one can think of – there are recipes out there for all tastes.

I feel that I cannot in all fairness finish this post without mentioning one negative thing about the Jerusalem artichoke: the plant has a tendency to be invasive, a problem I’ve written about several times. It’s the tubers – if you leave just one little piece in the ground, they will proliferate. This is fine if you have them planted in your garden or in a field; it means you don’t have a problem getting another harvest next year. But it is not fine if the tuber somehow jumps the garden fence or the field boundary. Like another invasive species which I recently wrote about, the Himalayan balsam, Helianthus tuberosus is particularly troublesome if the plant colonizes river banks, for the same reason. It dies back during winter, leaving the river banks much more exposed to the danger of erosion during winter and spring floods.

So, dear readers, bon appetit! But if you want to grow these tubers please make sure they don’t escape from your garden!

BEAUTIFUL FLOWER, DEADLY PLANT

Vienna, 27 September 2019

Picking up where I left off at the end of my last post, my wife and I were on our way back to our hotel from our little tour of Traunkirchen when I spied on the side of the road these beds of wild flowers.

They were really very pretty, with the flowers going from magenta to almost white, passing through a candy pink. Even as I admired and took a couple of photos I had to admit to myself that I no idea what they were.

The next day, at breakfast, I showed our host the pictures. Ah, she said, that’s a Drüsige Springkraut. She had no idea what its English name was, but the German name was enough for my wife. A few clicks later, she handed me her iPad and I was reading a Wikipedia entry on the flower.

Its official name is Impatiens glandulifera. It has many colourful names in English. Three – Policeman’s Helmet, Bobby Tops, Copper Tops – reflect the flower’s apparent resemblance to British policemen’s helmets. Here’s a close-up of the flower itself.

I leave my readers to decide, but I really don’t see this resemblance – unless the helmets have changed considerably since I last lived in the UK. Another name, Gnome’s Hatstand, makes more sense to me. It presumably harks back to the decidedly florid hats which some gnomes in children’s books sometimes sport, and I definitely can see a florid hat in the flower’s shape. And of course the plant then becomes the hatstand for these florid hats. Two other names, Himalayan Balsam and Kiss-me-on-the-mountain, refer to the mountainous origin of the plant; more on this later. Another name listed in Wikipedia is Ornamental jewelweed. I’m guessing this was inspired by the fact that we have a beautiful flower grafted onto a decidedly weedy-looking stem.

The English-speaking world seems to have been particularly poetic in its choice of names. The names in German and French (the only other two languages I checked) are decidedly more prosaic and seem mostly variations on balsam and glands (the latter being also found in the official name). I read that the plant does indeed carry glands, under the leaf stem, which produce a sticky, sweet-smelling, and edible nectar (the latter presumably being the origin of the balsam names). Eager to try this nectar, I poked around under various leaf stems the next time we walked past the flowers but failed to detect anything; a puzzle to be solved another day. The only exception to the list of prosaic Franco-German names is the German Bauernorchidee, Farmer’s orchid. We’ll come back to this link to orchids in a minute.

A beautiful flower – but alas an invasive species! Invasive species are a terrible problem; they have been the subject of an earlier post of mine. The flower’s original home is the Himalayas, specifically to the areas between Kashmir and Uttarakhand. I am ashamed to say that it was an Englishman who unleashed this particular botanical scourge on the rest of the world in 1839. He was no doubt part of that legion of Europeans who followed in the footsteps of conquering European armies, scouring the newly-colonized lands for plants. Initially, they were looking for plants from which some monetarily useful product could be extracted but later they also looked for pretty plants which they could sell to the growing ranks of gardeners looking for an extra splash of colour or texture in their gardens.

The Himalayan Balsam, to use one of its many names, was thus first grown outside of its natural range in the UK but eventually spread to many other parts of the world. Coming back to that German name, Farmer’s orchid, it seems that its popularity was at least in part due to it allowing gardeners of modest income to have a flower that looked very orchid-like; I throw in here a photo of an orchid, to allow readers to see the resemblance.

Real orchids were the playthings of the rich, who could afford not only the stiff purchase price but also the high maintenance costs (and by the way, the picture above is actually of a Victorian orchid hunter; orchids commanded prices which allowed serious expeditions to be funded).

As with water hyacinth which I wrote about in that earlier post on invasive species, the Himalayan balsam eventually escaped from the confines of gardens and began to spread through the countryside. As far as the UK is concerned, it has become one of the country’s most invasive species. It colonizes damp woodlands (which is where we came across it in Traunkirchen, although in beds that were not nearly as thick as this).

It also colonizes the banks of waterways – this is a view of the River Monnow, which makes up part of the England-Wales border.

The flower’s crowding along the banks of rivers is particularly problematical. When the plants die back in autumn they leave the banks bare and subject to erosion from winter and spring floods. I read that the plant is a terrible pest in the Norfolk Broads. That gives me pause; I used to go there as a young boy – 50+ years ago – and I never remember seeing it. The Himalayan balsam is marching across the landscape …

People are trying to do what they can to stop the plant. In some places, there are regular “balsam bashes”, where volunteers go out and physically pull up the plant. Here, for instance, we have a group of volunteers in Yorkshire, who by the size of the pile in front of them have had a hard day’s work.

More extreme measures are required, though, if the invasion is truly to be stopped. The basic problem is that the plant has escaped from all those predators which back home in the Himalayas keep it in check, and none have taken their place in the rest of the world. Researchers in the UK have gone off to the Himalayas to see if they can’t bring at least one of the original predators back to the UK. They have found a very promising candidate: the Himalayan balsam rust. It attacks the plant at various points: the stem, the leaves, the seedlings. This is what the leaves look like once they are under attack.

The scientists are currently conducting field tests. I wish them the best of luck. And I really pray that they will not unwittingly release into the British environment a rust that will find other, native species much more to their liking and which will then forget about attacking the Himalayan balsam. As I pointed out in my previous post on invasive species, this has happened before, and you end up with two invasive species instead of one!

While we wait for the results of the tests to come in, I invite readers to locate their nearest “balsam bash”, or whatever they might be called in the local language, and take part. You will be doing us all a favour and getting a breath of fresh air at the same time.

A beautiful flower, but to be admired in its native habitat and not in our gardens.

Bangkok, 25 October 2015

A few weeks ago now, my wife and I were greeted with this site when we came out for breakfast on our balcony overlooking the Chao Phraya River

Huge mats – small islands, almost – of water hyacinth were floating by, on their way to the Gulf of Thailand. So big were they that they were interfering with the water buses as they zig-zagged across the river from pier to pier. They had to slowly push their way through the mats, rather like ice-breakers, to reach the piers and let off their passengers. As the days went by the mats got smaller, and now there are only clumps moving to and fro with the tide, some with a white egret perched on them going along for the ride. A flotilla of yellow boats went by yesterday morning loaded up with baskets full of water hyacinth.

They must be part of some collection system. Given the amount of the stuff floating in the river, it seems a doomed effort, more a way for the government to give jobs to the boys than to really clear up the river’s water hyacinth problem.

When we first arrived here a year ago, these mats of water hyacinth floating by were one of the things which had struck us about the river. Then, over the months, they had disappeared. We had almost forgotten about them when those huge mats greeted us at breakfast that morning of a few weeks ago. I suppose the seasonal rains had filled canals and reservoirs upstream enough for someone to open dykes and dams to relieve the pressure and in the process clear out the water hyacinths which had been quietly growing there all year.

Water hyacinth has a beautiful flower

which is why someone (or someones) took it out of its original habitat, the Amazon basin, and carried it off to botanical and private gardens around the world. But from there, the plant somehow made it out into the big wide world and happily colonized waterways which had never known it and had no biological weapons to combat it. It grows very rapidly and soon was choking up waterways, beautifully of course, but still choking the life out of them.

Water hyacinth is considered an invasive species, that is to say, a species which is not native to a specific location and which has a tendency to spread in that new location to such a degree that it causes damage to the environment, to human health, and/or to the economy. That certainly describes the water hyacinth. It invaded the waterways of Louisiana and Florida in the late 19^th Century, choking them up. In Africa, it’s invaded many places. It’s invaded the Nile, all the way from Sudan to Egypt. It invaded Lake Victoria in the 1980s (it was brought to Rwanda by Belgian colonists, who wished to beautify their properties, and then escaped into River Kagera, which led it to the lake). This is Kisumu harbour on the lake.

In India, it has invaded the Kerala backwaters.

In South-East Asia, apart from the Chao Phraya River and many, many other places, it has invaded Tonlé Sap Lake in Cambodia, a lake with a very unique ecology.

If you don’t control it, water hyacinth will cover lakes and ponds entirely, as these pictures show. This dramatically impacts water flow, it blocks sunlight from reaching native aquatic plants, and it starves the water of oxygen, often killing aquatic species. The mats are also create great places for mosquitos to live, as well as a species of snail known to host a parasitic flatworm which causes schistosomiasis.

I am reminded of a beautiful but evil woman: shall we say Julia Roberts as Snow Queen?

OK, to be gender-neutral let me also suggest a handsome but evil man: shall we say Robert Pattinson as Edward Cullen in Twilight?

To be fair to water hyacinth, it is not the only invasive species by any manner of means. There must be hundreds if not thousands of species which are considered invasive in some corner of the globe. The International Union for the Conservation of Nature (IUCN) has come up with a list of the 100 worst invasive species, confessing that it had great difficulty in squeezing the list down to a mere hundred (although water hyacinth did make it onto the list). Reading the list is eye-opening and depressing. Let me make a relatively random selection of a few of them. Kudzu, which has been receiving a lot of bad press as an invasive species, is on the list, and if this picture of a house smothered by kudzu is anything to go by, with good reason.

Originally from China, it was introduced to Japan, and from there to the US as an ornamental. Then during the 1930s farmers were paid to plant kudzu to combat soil erosion. Then it went crazy.

The brown tree snake, which has also received a lot of bad press as an invasive, is on the list too.

Originally from northern Australia, New Guinea, and some of the nearby islands, it was accidentally introduced into the island of Guam in the late forties-early fifties, maybe by crawling into the landing gear of an aeroplane, maybe as a stowaway on a ship. Once on the island, it went crazy, decimating, and in some cases completely eliminating, certain species of birds and rodents. Since Guam is a big transport node, it’s highly possible that the snake will get carried to other islands in the Pacific.

The fungus Batrachochytrium dendrobatidis, or Bd as it is known, is also there.

This little bugger has been wiping out frog populations all over the world, down to extinction in some cases. Only discovered in 1998, it’s thought that Bd originated in Africa and subsequently spread to other parts of the world by trade in the African clawed frog. Another fungus on the list is Ophiostoma ulmi sensu lato, better known as the fungus that causes Dutch Elm Disease. Originally from Asia, it somehow got into Europe in the early 1900s, probably in a shipment of Asian elm, but it was a mild form and was contained. From the Netherlands, it got into the US in the 1920s, through New York, where it has slowly but surely been killing off the North American elms. A much more virulent strain came back into Europe from the US in the late 1960s, probably in some infected wood, and has been killing off European elms ever since. This view of Salisbury Cathedral, for instance, painted by John Constable in 1820, is no more; the magnificent elms to the left have all died.

Closer to home, did you know that the cat is an invasive species?

Well, it is in certain parts of the world like New Zealand or Australia, or even the US. European colonists brought them, they have gone feral – or they just hunt for the fun of it – and have decimated, if not obliterated, certain bird species, and continue to do so. It’s so bad that it has made in onto the list of the 100 worst.

Staying with the familiar, the goat – an aggressive “eating machine” – is on the list, as are the rabbit, the red deer, the fox, the starling, and the rainbow trout, all introduced into new habitats by European colonists to make the colonies more like home, and all causing damage to the new ecosystems they found themselves in .

Going small again, I pick a mollusk from the list, the cannibal snail.

I pick it because it teaches us an important lesson in the fight against invasive species. The snail is an invasive in Hawaii, where it was originally introduced to try to eliminate another invasive species, the giant African land snail. Our friend is a fast and voracious predator, hunting and eating other snails and slugs, which gives it its pretty nickname. So the hope was that it would go after the giant African land snail. But instead, it went after the indigenous O’ahu tree snail species. And it went after them so enthusiastically that many of the species were extinct within a year. This is the risk with introducing a new predator to prey on an invasive species. There are chances that the predator will find other, indigenous, prey more yummy or simply easier to hunt, and you now find yourself with two invasives on your hands rather than one. Stoats, also on the list, fall into this category. Introduced into New Zealand to control the invasive rabbits and hares, it went after the indigenous birds instead, so now New Zealanders are left with trying to get rid of the stoat as well as the rabbit and hare.

For another plant on the list, the prickly pear, I refer the reader to an earlier post which I wrote about it. I’ll finish with a small tree, the cedar tree.

I add it simply because my French grandmother had one in her garden, and I loved climbing it when I was small. It was OK for her to have it, it is native to Europe and Asia. But when this tree, with its lovely pink flowers and feathery leaves, was introduced into the Southwestern US it was a disaster.

I invite readers to look at the list. It is quite sobering. In fact, as I study it, it occurs to me that there is one horribly invasive species that is not on it: homo sapiens sapiens.

This species left its original home in Africa 70,000 years ago and slowly spread all over the world. In at least three places, Australia, North America, and much later New Zealand, its arrival seems to have triggered a massive die-off of the bigger indigenous fauna, probably because they didn’t have sufficient defences against its clever hunting habits. About two hundred and fifty years ago, the species started the so-called scientific and industrial revolutions, which have resulted in it now having unprecedented power over all other species. It has, for its amusement or to make money or to protect one of its enslaved species (its agricultural crops and its livestock) from predatory attack or simply by mistake, moved species around the world, creating all the ecological catastrophes I’ve touched on above. And because it is taking living space away from all other species, crowding them out much more effectively than the kudzu pictured above is, it has set off the greatest die-off of species that the planet has seen in the last 66 million years.

I really think it should be on the list. I must write to the IUCN suggesting it.

__________________________

Water hyacinth on the Chao Phraya River: my photos
Water hyacinth flower: https://upload.wikimedia.org/wikipedia/commons/5/56/Common_Water_hyacinth.jpg (in https://en.wikipedia.org/wiki/Eichhornia)
Water hyacinth in flower in canal: http://img.tamtay.vn/files/2008/02/25/dinhkhoa/photos/247869/48c4920a_a019_resize.jpg (in http://blog.tamtay.vn/entry/view/472876/Thang-Sau-Co-loai-ve-dai-dot-trot-vuong-vao-yeu.html)
Kisumu harbor, Lake Victoria: https://en.wikipedia.org/wiki/Eichhornia_crassipes#/media/File:Kenya_Kisumu_Harbour_Hyacinths_1997ke09b21.jpg (in https://en.wikipedia.org/wiki/Eichhornia_crassipes)
Kerala backwaters: https://en.wikipedia.org/wiki/Kerala_backwaters#/media/File:Kerala-Backwaters_Alppuzha.JPG (in https://en.wikipedia.org/wiki/Kerala_backwaters)
Tonlé Sap: http://lh3.ggpht.com/-KcgJUhcsvQU/UE2G1p3L3GI/AAAAAAAAJl8/0bHMUxxUTAg/IMG_3439_thumb2.jpg?imgmax=800 (in http://jemamum.blogspot.com/2012/09/chong-kneas-floating-village-lake-tonle.html)
Julia Roberts snow queen: http://i.dailymail.co.uk/i/pix/2011/10/07/article-2046339-0E455A1E00000578-532_634x832.jpg (in daily mail; exact site is blocked by the Thai Ministry of Information)
Edward Cullen in Twilight: http://celebspics.org/wp-content/uploads/2012/11/05-Twilight%E2%80%99s-Breaking-Dawn-Part-2-The-Complete-Character-Gallery.jpg (in http://celebspics.org/twilights-breaking-dawn-part-2-the-complete-character-gallery/)
Kudzu: http://41.media.tumblr.com/d6bc26739854ba64e2b54c06a1993889/tumblr_ns2cl4QrQZ1r8vrhxo1_500.png (in http://sleepy-times.tumblr.com/)
Brown tree snake: http://islandarks.com.au/files/2013/03/Brown-Tree-Snake-.jpg (in http://islandarks.com.au/tag/brown-tree-snake/)
Batrachochytrium dendrobatidis: http://www.diark.org/img/species_pict/large/Batrachochytrium_dendrobatidis_JAM81/ (in http://www.diark.org/diark/species_list/Batrachochytrium_dendrobatidis_JAM81)
John Constable Salisbury Cathedral: https://en.m.wikipedia.org/wiki/Dutch_elm_disease#/media/File%3ASalisburyCathedral.jpg (in https://en.m.wikipedia.org/wiki/Dutch_elm_disease#Disease_range)
Cat: http://i1251.photobucket.com/albums/hh554/lemabang2008/Desktop%20Wallpaper/Cats%20Wallpaper%202/wildcat.jpg (in https://lemabang.wordpress.com/2012/08/19/desktop-wallpapers-2/)
Cannibal snail: https://en.m.wikipedia.org/wiki/Euglandina_rosea#/media/File%3AEuglandina_rosea.jpg (in https://en.m.wikipedia.org/wiki/Euglandina_rosea)
Cedar tree: https://en.m.wikipedia.org/wiki/Tamarix_ramosissima#/media/File%3ATamarix_ramosissima_a2.jpg (in https://en.m.wikipedia.org/wiki/Tamarix_ramosissima)
Human family: http://thumbs.dreamstime.com/z/family-sitting-garden-together-15588689.jpg (in http://www.dreamstime.com/royalty-free-stock-images-family-sitting-garden-together-image15588689)