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Saturday, 14 November 2015

Scotching the thistle

Thistles are a serious menace in Australia, introduced weeds that run wild. I plan here to discuss the past history of the plant in Australia, and then discuss what is involved in reducing the scourge.

I am sufficiently separated from my Scots forebears to share none of their love of the thistle, but in a time when Scots in Australia were all first-generation and sick for the lack of pibrochs, bonnie braes, and haggis and neeps, the thistle was an essential adornment for their St Andrew’s Day, Hogmanay and Burns’ Night celebrations. The thistle was also the Antipodean Scots' symbol, and as early as 1817, one James Chisholm kept a house called the ‘Crown and Thistle’ in Sydney.

In 1823, Donald M’Lean was publican at the ‘Scotch Thistle’ in Hobart. Now a word on terms: my forebears would say you could scotch a snake not kill it, and that one could drink Scotch whisky. A later generation added Scotch tape as a trade mark, but otherwise, they said, the correct descriptor was Scots. Well Onopordum acanthium, usually taken to be THE Scotch thistle, is always called Scotch. Mind you, what is meant by "Scotch thistle" is often Silybum marianum. No matter, they are all pests.

Which plant it is matters little to the Scots, who revere the thistle in a general way, because in legend, a Norseman, part of a sneak attack, yelled out in pain when he ran into a thistle, giving the alarm and saving the Scots. If it prickles a Viking, it’s a thistle. Oh, and just to confuse the issue, 19th century laymen often called it Carduus.

We are happy to observe that Mr. Gordon of Forcett, has received by one of the last ships which arrived from England at Launceston, a few seeds of a magnificent variety of the real Scotch thistle. It has been not inaptly called Carduus Burniensis, from being found originally within the iron railing which surrounds the grave of the poet Burns at Dumfries. On the 1st of June last, which is scarcely half the growing season in England, the leaves were upwards of a yard in length.

The Hobart Town Courier, Saturday 8 March 1828, 3, http://trove.nla.gov.au/ndp/del/article/4223780
Still, the Scots’ celebration of St Andrew in Hobart in 1829 (appropriately, at the Macquarie Hotel), lacked any real thistles. By 1832, the Scotch thistle was a pest in Hobart, and the fault lay, not with a Scot, but with that carousing clergyman and magistrate, Robert Knopwood (who was born in Norfolk, in case you were wondering):
A few years ago when the Rev. Mr. Knopwood lived at Cottage Green, he happened to have a Scotch thistle in his garden; the seeds of which disseminated themselves along the shore at the Battery, and the plants springing from them were admired and religiously protected by emigrating patriots of old Scotia who approached them.
 Since that time however they have become so numerous and have spread themselves so widely that almost every field and garden for miles around is more or less infested with them and the purpose of our remark at this time when the winged seeds are on the point of quitting their native pedestals, is to entreat those who have any interest in fields or gardens to use some diligence in destroying them.

The Hobart Town Courier, 28 January 1832, 2, http://trove.nla.gov.au/ndp/del/article/4200297

Two months later, a correspondent to the same paper called for urgent action to eradicate the “Scotch thistle”:
Let the Government order such a number of prisoners as may be necessary, under proper superintendence, to destroy every plant of it to be found in the neighbourhood… It is not as yet in seed, and close attention for 2 or 3 years in this manner, would, I trust, save the whole island from certain evil, the extent and injury of which is scarcely to be calculated.

The Hobart Town Courier, 3 March 1832, 2, http://trove.nla.gov.au/ndp/del/article/4200099

Well, that didn’t happen, and in 1841, the Hobart Town Advertiser suggested a new tool to its readers:
… we recommend those of our readers who intend to wage war against that most formidable pest, the Scotch thistle, to adopt the kind of hoe or spud used by Mr. Gordon, and well adapted for the purpose, as it serves also as a walking stick. It is about three inches wide, made strong, and with a staff made conveniently heavy. It is a good weapon also for snakes, or rather against these intruding reptiles.

— Quoted in The Courier (Hobart), 8 January 1841, 2, http://trove.nla.gov.au/ndp/del/article/2957324


Thistles are good at travelling, and in 1846, people were getting alarmed in Geelong, and some of them wrote to the papers about the thistles, lurking and massing, just across the Bass Strait:the invasion was coming, they warned.
… the Scotch Thistle. It is only a few years since the seed was imported, and it is already beyond the art of man to eradicate this most pernicious and useless weed. There is scarce a doubt, if the thistle is allowed to spread as it has done, that in the space of a few years it will completely destroy the pasturage, and then farewell to our wool growing prosperity. In the interior on the rich soils, the thistle grows much more vigorously than on the strong hills in the vicinity of the metropolis; some plants have a circumference of several, feet, six feet or more, and will produce some thousands of seeds; indeed the fecundity of the thistle is beyond belief.

Geelong Advertiser and Squatters’ Advocate, 25 April 1846, 4, http://trove.nla.gov.au/ndp/del/article/94444658
I have to say that when I was young, "fecund" sounded like a really rude word. The youngster within me likes to think that any word applied to thistles should be rude.  The aged hunter of the thistle that is me now, says "Fecund, fecund, fecund!".

Anyhow, in spite of what the paper said, nothing happened, and the inevitable followed, as the same paper reported in 1848:
THISTLES.-Within the last few days, the discovery has been made that this insidious weed has sprung up in several places near Geelong. Its identity with the Scotch thistle of Van Diemen’s Land has been doubted by some, but we are afraid that it will be found to be too truly so.


Geelong Advertiser, Nov. 21, http://trove.nla.gov.au/ndp/del/article/93137604
In 1849, the same paper returned to the attack:
… the rapid propagation of the Scotch thistle has been productive of incalculable injury in the neighbouring colonies, yet our colonists appear totally indifferent to the matter, although year after year rich pasture lands have become over-run with these vegetable plagues, and have been suffered to spread over the country without any efficient means being adopted for their extermination The thistle was probably imported in the shipments of hay once so frequent from Van Diemen’s Land, and made its appearance first in the neighbourhood of the flag-staff hill, Melbourne, from whence it soon spread to Keilor, but may now be found so far up as the Wardy Yallock, and unless the settlers set to work in earnest and speedily check their progress, thousands of acres of our most valuable lands will soon be rendered totally unfit for either pastoral or agricultural purposes.


Geelong Advertiser, 12 July 1849, 2, http://trove.nla.gov.au/ndp/del/article/93135028
The Argus (a Melbourne paper, printed some 70 km from Geelong) had a different view of how the thistle arrived, a few days later:
This is certainly not the true origin of the introduction of the thistle, for we well recollect it first grew on the green knoll, a little to the south of Liardet’s Inn, on the Beach, about where the residence of the Custom’s Officer is now built, and it has gradually radiated from that centre with the course of the prevailing winds. In all probability it was introduced as a garden flower, as it is said to have been in Van Diemen’s Land, by an enthusiastic Scotchman, who sent home for a supply of the thistle seed, and on its receipt took his seat on the top of the stage coach from Hobart Town to Launceston, and scattered the seeds right and left the whole way. At all events, we well recollect that when it first appeared at the spot we speak of, a “brother Scot,” we wot of, was at great pains to procure healthy specimens of “the emblem dear,” for transplantation into his garden in Melbourne.


The Argus, 16 July 1849, 2, http://trove.nla.gov.au/ndp/del/article/4775150
The Geelong Advertiser returned to the topic of thistles again later in the year, through a correspondent at Devils River, north-west of Melbourne, and now the Scots were the target:
… the Scotch Thistle … this noxious plant is now firmly rooted, and has propagated itself extensively, even in this district, one hundred and fifty miles from Melbourne and Geelong, is but too true, and threatens to overrun the soil in all directions. Last year it was noticed in some parts of this locality, but so scarce and unconnected as to create no serious apprehension; but this year however bears ample and fearful testimony of its propagating quality; thick and stubborn clumps being found, where not a vestige of its existence could be perceived before. This is particularly the case along the banks of creeks and water-courses…

The Introduction of the Scotch Thistle into the Devils’ River district was by a Scotch gentleman, who, before the dissolution of the Company, superintended the stations of the Messrs Watson and Hunter, and who it would appear, enamoured of every or anything from the ‘land o’ cakes,’ no matter how pungent or repellant, in the full bloom of his patriotism transplanted the emblem of Caledonia into the very heart of Australia Felix?

Such is patriotism! But the patriot did not stop here, he caused one of his subordinates, an unfortunate overseer, who is now a settler on this River, and who sorely repents the patriotic enthusiasm of his former superior, to plant some of the ornamental but noxious thistle in his garden. The overseer, who would not be outstripped in amor patriƦ, gave some seed to others, and thus their darling thistle was nourished, nurtured, and propagated, and in due time has become to be no very great rarity…


Geelong Advertiser, 9 August 1849, 1, http://trove.nla.gov.au/ndp/del/article/93138358
 But was he right? In 1886, J. A, Froude described another way that weeds could spread, after a discussion with Captain (later Professor) Ellery at the Melbourne Observatory:
The Observatory was but a quarter of a mile distant, but in the forenoon, and under a Victorian sun, we had a mauvais quart d’heure in getting there. On the way, amidst some coarse grass, I beheld a scarlet pimpernel, the veritable ‘poor man’s weatherglass’ of northern Europe, basking wide open in the rays. If I had been studying the language of the New Hebrides, and had found imbedded in it a Greek verb, perfect in all its inflexions, I could not have been more surprised. How in the wide world came a highly organised plant of this kind to be growing wild in Australia? Had the seed been brought by some ship’s crew, or in a bird’s stomach, or been wafted over in the chambers of the air? To what far-off connection did it point of Australia with the old world? I gathered my marvel, and carried it to Mr. Ellery to be explained. How idly we let our imagination wander! He laughed as he said, ‘Many weeds and wild flowers from the old country make their first appearance in this garden. Our instruments are sent out packed in hay.’


— J. A. Froude, Oceana, 1886. 
At the end of the 19th century, an Irish-Australian politician was sure he knew which race was responsible:
A Scot introduced their charming thistle, and we will have to put a sum on the estimates to extirpate it. Edward Wilson introduced the sparrow, and the sparrow is playing havoc with our vineyards. Some busybody introduced the rabbit, and the income of Ballarat would not save us from the consequences.


— Sir Charles Gavan Duffy, My Life in Two Hemispheres, 1898.
And now, scotching the thistle

Just a note here: you can see most of these pics full-size, if you click on them.

This diatribe was brought about by my Big Game Hunt today. I am a volunteer gardener and things in the Nursery Group at the North Head Sanctuary, and one of my aims is to wipe out what we call Scotch thistle, and I am fairly sure it is Onopordum acanthium. This morning, I found two large plants, about to set seed, so I get out the Big Game Hunter's Tool Kit.

Some background: I have been working over this infested area for maybe 18 months now, mainly digging up young plants, but digging disturbs the soil and gets other weeds going, so it is preferable to use topical weedkiller. I use a benign one that requires no protective clothing.

The problem seems to have begin with one seed that grew to maturity. At some point, some idiot chopped the first plant down and left it there.  The seeds continued to escape, and we came across the infestation as the second generation was springing up.  I removed the old plant, but now we have a large seedbed to contend with, because some of the second generation reached maturity. If we stay on it, sooner or later, we will win.

The only way to wipe out thistles is to remove all the flowering and seeding heads with the small secateurs, then cut off the flowerless stems which can be left to rot, while the flowering heads are destroyed. Then the main stem, and on some of my prey today, that stem was 3 cm across, is cut with the big loppers, and the stem is then poisoned. Because there are people out there who know nothing about poisons, but have opinions, I'm not saying what it is. Suffice it to say that I know quite a bit about poisons, and I see no need for protective gear. or to argue with the ignorant, so they will get no traction here.

Now here is how the operation proceeds:

The Big Game Hunter has to infiltrate, because the plants often lie in concealment, as you can see here on the left. The Hunter has to sneak up on them, and while they quiver with rage. To get close you cut back the dead wattle bushes they are hiding in.

The flowering heads (right, above) are snipped off, wearing a raincoat and gauntlets, then the branches are taken off and inspected, working down to the base. It's slow work: it took me the best part of an hour to take out six plants — it had looked like two plants, but they were growing in a small space.

Then all that remains is for the Great Hunter to return to base, with the flowering heads of his prey in a basket, for the obligatory trophy shot, posing with one's foot on their heads, exhibiting his weapons. Thanks to Jenny Wilson for the last shot: the rest were All My Own Work.

Why kill the thistles? Simple: we have the now rare Eastern Suburbs Banksia Scrub growing on North Head, and thistles just don't belong in that.  Not only that, if the thistles got away, I suspect that the animals we are trying to protect would also face problems.

What you see in the basket, above left, is just the flowering heads and many, many seeds or potential seeds. Back to the Geelong Advertiser again:
The following is the calculation of a naturalist: “Another species of thistle called the Aranthum Vulgare, produces about 100 heads, each containing from 300 to 400 seeds. Suppose we say that these thistles produce at a medium only 80 heads; and that each contains only 300 seeds, the first crop from, these would amount to 24,000. Let these be sown, and their produce will amount to 546 millions. Sow these, and their produce, will be 13,824,000,000,000, or thirteen billions eight hundred. and twenty-four thousand millions, and a single crop from these, which is only the third years’ growth, would amount to 331,776,000,000.000,000. or three hundred and thirty-one thousand seven hundred and seventy-six billions; and the fourth years’ growth will amount 7,962,624,000,000,000,000, or seven thousand nine hundred and sixty-two trillions six hundred and twenty four thousand billions — a progeny more than sufficient to stock not only the surface of the whole earth, but all the planets in the solar system, so that no other plant or vegetable could grow, allowing but the space of one square foot for each plant.”

Geelong Advertiser and Squatters’ Advocate, 25 April 1846, 4, http://trove.nla.gov.au/ndp/del/article/94444658
I do not question the sums, and that's why we seek to scotch the thistles!




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