Introduced Plants and Animals of Victoria

A common weed

Cirsium vulgare (Spear Thistle) is a robust thistle with spiny leaves and large, almost globular, purple flowers heads, which is found throughout Victoria with the exception of the low-rainfall areas of the north-west. It is native to Europe, including Britain, and was probably introduced to Victoria by accident amongst seeds of pasture grasses at the time of European settlement. By the 1850s Cirsium was found throughout the pasture country of Victoria and was considered to be such a problem to graziers that it was one of only five species that were targeted in the Thistle Bill of 1856 - the forerunner to the Vermin and Noxious Weed Act (now covered under the Catchment and Land Protection Act 1994).

When the term noxious weed was coined it referred to plants that were problems in agricultural land and for the most part these species didn't invade native vegetation to any great extent. Of the original five species covered by the Thistle Bill three are still more or less confined to pasture country and roadsides while one is no longer found in Victoria. Cirsium vulgare, on the other hand, is now the most widespread of all Victorian plant species and it grows in a large range of native vegetation communities - it is considered to be a characteristic species of 30% of the described Ecological Vegetation Classes (EVCs) in Victoria.

Cirsium vulgare - Spear Thistle

There has been some confusion in Victoria over what common name should apply to Cirsium vulgare. Many people call it Scotch Thistle but botanists will point out that this name has been applied most often to another weed species Onopordum acanthium. Indeed the introduction of Onopordum to Victoria was as a horticultural plant associated with Scottish heraldry, that is, it was grown in the gardens of a number of graziers (many of whom were Scots) as a representative of the thistle emblem of Scotland.

The history of the thistle in Scotland dates back to a 13^th century legend when a Viking force attempted to surprise the Scots by coming ashore at night and removing their footwear so that they could approach the coastal garrison quietly. The legend states that one or more of the Vikings stepped on thistles and cried out in pain thus warning the clansmen of the invasion. From that time on the thistle was the emblem of Scotland and in 1470 King James III formalised this by ordering silver coins to be embossed with the thistle as a royal symbol. There appears to be nothing in the historical literature that suggests which species of thistle was responsible for the warning but at some point Onopordum acanthium seemed to become accepted as the best candidate. The problem with this is that Onopordum isn't native to Britain, isn't very common in Scotland, and may not have been introduced to the country until the 20th century. Joseph Hooker, the director of the Kew Botanic Gardens, alluded to this anomaly when he wrote, in 1892, that Onopordum was '...Now found in several parts of England, but certainly not wild in Scotland...'

Cirsium vulgare is a native of Scotland, has always been common across the British Isles and is currently the most abundant Scottish thistle. It has been suggested by a number of Scottish authors that this is the species that best fits the legend and that Onopordum, with its pale blue-green leaves and stems. is simply a more attractive looking alternative. These same authors also make it clear that Scots don't use the word Scotch to describe anything. In Britain Onopordum is called Cotton Thistle, sometimes Heraldic Thistle, but never Scotch.

There is an irony in this story. Now there is a reasonable argument that Scotch Thistle is a suitable common name for Cirsium vulgare, it is also clear that the Scots themselves regard the name as wholly inappropriate. There is also a second irony concerning Onopordum acanthium. It was one of the first species to be classified as a noxious weed, in 1856, but there is no compelling evidence that it was a serious weed at the time. This leads inexorably to the suggestion that perhaps those who drafted the early legislation were also confused about the abundance and identity of Scotch Thistle. This should be no surprise as there are many records for Onopordum acanthium, that have been submitted to the Victorian Illustrated Flora Information System over the years, which were actually Cirsium vulgare. This no doubt happened because the observers saw Cirsium, which they knew as Scotch Thistle, then later, incorrectly, assigned the accepted scientific name of Onopordum. This problem is not unique to Victorian observers either, as a quick browse through the Web shows many pages with information about Onopordum accompanied by images of Cirsium.