Cirsium vulgare, commonly known as spear thistle, bull thistle, or common thistle, is a species of the Asteraceae genus Cirsium, native throughout most of Europe (north to 66°N, locally 68°N), Western Asia (east to the Yenisei Valley), and northwestern Africa (Atlas Mountains). It is also naturalised in North America, Africa, and Australia and is an invasive weed in several regions. It is the national flower of Scotland.
The plant provides a great deal of nectar for pollinators. It was rated in the top 10 for most nectar production (nectar per unit cover per year) in a UK plants survey conducted by the AgriLand project which is supported by the UK Insect Pollinators Initiative. Marsh thistle, Cirsium palustre, was ranked in first place while this thistle was ranked in sixth place. It also was a top producer of nectar sugar in another study in Britain, ranked third with a production per floral unit of (2300 ± 400 μg).
Description
It is a tall biennial or short-lived monocarpic thistle, forming a rosette of leaves and a taproot up to 70 cm (28 in) long in the first year, and a flowering stem 1–1.5 m (3 ft 4 in – 4 ft 11 in) tall in the second (rarely third or fourth) year. It can grow up to tall.
Ecology
Spear thistle is often a ruderal species, colonising bare disturbed ground, but also persists well on heavily grazed land as it is unpalatable to most grazing animals. The flowers are a rich nectar source used by numerous pollinating insects, including honey bees, wool-carder bees, and many butterflies. The seeds are eaten by goldfinches, linnets and greenfinches. The seeds are dispersed by wind, mud, water, and possibly also by ants; they do not show significant long-term dormancy, most germinating soon after dispersal and only a few lasting up to four years in the soil seed bank. Seed is also often spread by human activity such as hay bales. and a noxious weed in Australia and in nine US states. Spread is only by seed, not by root fragments as in the related creeping thistle C. arvense. It is best cleared from land by hoeing and deep cutting of the taproot before seeds mature; regular cultivation also prevents its establishment. Scots, Scottish, or Scotch thistle, and common thistle. They are often pickled in cajun cuisine. The tap roots can be eaten raw or cooked, but are only palatable on young thistles that have not yet flowered. The dried florets steeped in water are used in rural Italy for curdling goats' milk in preparation for making cheese. In Iran, cleaned stems are used in the dish Khoresh-e-Kangar (thistle stem stew).
In culture
The plant features in some Scottish ceremonies such as the "Riding of the Marches", held annually in Langholm in July. The 1992 specimen measured six feet in length.
Spear thistle is also the emblem of Newton Regis in England.
- Purple Flower – 'Independence, Strictness, Austerity, Do Not Touch'
- Pink Flower – 'Dignity, Strictness, Friendship, Joy, Romance'
- White Flower – 'Purity, Spirituality, New Beginning'
- Blue Flower – 'Rarity, Originality'