In the last few hundred years, the story of the people of Scotland has been one of emigration. As roughly estimated by a Scottish sociologist, if no one had emigrated from Scotland in the last 25 years, the population would more like 8 million, than the 5 million currently living there (Scottish Census 2001). Scottish people had a habit of leaving their homeland, and going…. Everywhere. And wherever they went, they took their national symbol with them.
The plant known as the Scottish thistle today, Onopordum acanthium, is an impressive member of the sunflower family by many standards. Native to Europe and Western Asia, its leaves are wooly and edged in sharp spines, as are its globe shaped, artichoke-like purple flower heads. Even the stems, up to 8 ft tall, are lined with spiny wings. It’s not what you might call a cuddly plant. Reportedly, this quality is what so endeared it to the Scottish; bands of marauding Vikings lost the element of surprise when they stumbled into these monsters. An appropriate common name for this plant, in Portuguese, is cardo-bastardo.
With willing human-born transportation and the toehold provided by the eager gardens of Scottish emigrants, Scottish thistle has been able to spread across the globe, with significant invasions in North and South America, Australia, and New Zealand. Invading dry rangelands, this national symbol of a distant land can grow densely, smothering less well defended natives. This is especially problematic along waterways, where the spiny stands create a barrier between the water and the dry lands other inhabitants.
By the way, national symbols can be tasty too. The flower heads can be eaten just like artichokes, and the stems peeled and steamed, like asparagus.