Perennial Sowthistle (Sonchus arvensis)

Dear Readers, my friend A sent me the photo above. 

‘What’s this triffid?’ she asked (the plant looks as if it’s about the height of a primary-school child).

Well, it turns out that it’s a Perennial Sow-thistle, also known as a ‘dindle’, though why I have not yet been able to ascertain. To dindle meant ‘to vibrate or tingle’ . When I Google the word it keeps presenting me with ‘dirndl’, which is one of those Tyrolean long skirts, worn with a lacy apron, and is not at all the same thing. Like all members of the Sowthistle genus, the milky sap was believed to improve lactation when eaten by domestic animals, particularly pigs.

It’s certainly an impressive plant, and it’s one of the ‘yellow Asteraceae’ that we were told not to try to identify when I went on a field course about twenty years ago – what with all the hawkbits and hawksbeards and nippleworts and dandelions it’s a very tricky family. But this one is pretty clear – it has nice shiny leaves, several large yellow flowers on each stem, and while it produces white latex like so many plants in the family, it doesn’t turn orange, which that of the Prickly Sowthistle and Smooth Sowthistle does.

Leaves of Perennial Sowthistle

Perennial Sow-thistle (Illustration Public Domain)

The Botanical Society of Britain and Ireland (BSBI) describe Perennial Sowthistle thus:

‘This patch-forming, horizontally spreading perennial, with its stems up to 150 cm tall, is very conspicuous and unmistakable as it waves to the passing motorist from the roadside verge from late July through to October as it bears its large, bright yellow, dandelion-like flowerheads.’

I very much like the description, although ‘our’ plant is clearly a bit early. The BSBI go on to say that although the plant  is classed as a dangerous weed in many countries, in the UK many of the seeds are eaten, particularly by beetle larvae, and of the rest only about 40% are viable. However, as each plant can produce 13,000 seeds per season, and as the plant can also reproduce via rhizomes, it can quickly grow into a clump if the conditions are correct. On the other hand, it looks to me to be rather more attractive than most of the other sow-thistles, which often look very knocked-about by the time all the leaf-borers and mildews have had a go at them. Plus, all manner of pollinators love the flowers.

Photo by Phillippe Juillerat at https://www.infoflora.ch/en/flora/sonchus-arvensis-subsp-arvensis.html

My friend A, an inveterate forager, was also curious as to whether the plant was edible. My initial reaction was ‘no’ because of the white sap, but then  dandelion leaves are perfectly safe to eat (if not grown where they can be contaminated by dogs or pollution), and indeed the leaves of this plant, too, are said to be bitter but fine in a salad, particularly when young. You can find a few recipes here. One legend has it that Theseus feasted on sow-thistle before he entered the labyrinth to do battle with the minotaur.

On the other hand, while many creatures eat the leaves of the Perennial Sow-thistle, one of the rarest and most spectacular is the caterpillar of the Striped Hawkmoth (Hyles livornica). The adult moth is an immigrant which lays its eggs on a variety of plants, but particularly Perennial Sow-thistle. The caterpillars don’t often survive the winter (yet) but are well worth looking out for, with their black and yellow livery and natty red ‘feet’.

Striped Hawkmoth(Hyles livornica) – Photo by By Hectonichus – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=12673640

Caterpillar of the Striped Hawk Moth (Photo By picture taken by Paolo Mazei – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=6346422)

Like many plants that produce milky latex, Perennial Sow-thistle also has a reputation for curing warts if the sap is applied to the area in question. In Wales, it was believed that carrying a sow-thistle leaf in the hat or belt would protect the person from ‘the devil, witches and hags of the night’. On the other hand, a person wearing a leaf could walk and never tire, although anyone walking alongside would tire more quickly and eventually die, which seems like a bit of a rum bargain if you ask me.

And here is a poem by Irish poet Annemarie Ní Churreáin. I rather loved it. See what you think.

Sow-thistle by Annemarie Ní Churreáin

at St Joseph’s Industrial School, Dundalk, Co Louth (1881-1983)

Here, in the aftermath of the orphanage,
I watch the local schoolgirls gathering
along the street’s chipped, black railings
and, two by two, link slender arms to troop
uptown against the sun, all high heads
and clear temples, all grit and burning,
all clean hair flashing ponies.
Who knows the earth more than a girl?
Who knows the auguries of stone?
We were often told, you are the lowest of the low,
we cupped our hands to the grass to see how low.
What cannot be written is rising up
through the cracks. I kneel to a sowthistle,
leaf-starred and gold between my fingers,
the stalk throbbing light. I encounter
its living testimony, as closely as I
would encounter the expert findings
of any state report.

Photo by Françoise Alsaker at https://www.infoflora.ch/en/flora/sonchus-arvensis-subsp-arvensis.html