Species at Risk
Mingan Thistle with identification tag. © Parks Canada / MANPRC/ A.Boudreau/ 2005
What is the Mingan Thistle?
The Mingan thistle (Cirsium scariosum) aka meadow thistle is a rare plant from the Aster family (Asteracea).
It is hard to distinguish from other species until it flowers because for most of its lifespan, it is made up of basal leaves only. It grows generally from one summer to the next until basal leaves reach a diameter between 0.7 and 111 cm. Then, between the ages of 4 and 19 years old, the Mingan thistle flowers only once around mid-July and dies. At this stage, it has a stem (between 2.6 and 99.5 cm) ending with pale purple to pink capitulums.
Each “flower” is actually a capitulum made of many tiny flowers.
At maturity, the seeds are topped by aigrettes or feathery crowns and fall near the plant. Seeds are their only mean of spreading.
Where is Mingan Thistle found?
The most likely hypothesis to explain the Mingan thistle’s geographic distribution is that it could be a remnant of Western flora that established itself in the area following the last ice age.
In Quebec, the Mingan thistle is only found in the Mingan Archipelago National Park Reserve where it grows mainly along the coast of four of the islands of the park reserve. Elsewhere in Canada, the species can be found in a small area south of Alberta and British-Columbia; it can especially be found in Waterton Lakes National Park. The two distribution areas are 3,500 km apart.