Cirsium is a genus of perennial and biennial flowering plants in the Asteraceae, one of several genera known commonly as Thistles. They are more precisely known as Plume Thistles. Thistles are mostly native to Eurasia and northern Africa. The word "Cirsium" derives from the Greek word "kirsos," meaning "swollen vein."
Thistles are known for their effusive flower heads, usually purple, rose, or pink, also yellow or white. The radially symmetrical disc flowers are at the end of the branches and are visited by many kinds of insects, featuring a generalized pollination syndrome. They have erect stems and prickly leaves, with a characteristic enlarged base of the flower, which is commonly spiny. The leaves are alternate, and some species can be slightly hairy.
Certain species of Cirsium, like Cirsium monspessulanum, Cirsium pyrenaicum, and Cirsium vulgare, have been traditionally used as food in rural areas of southern Europe. Cirsium oleraceum is cultivated as a food source in Japan and India. Thistles were used as a remedy against swollen veins.
Growing Conditions and General Care
The seeds of Cirsium can be sown in either autumn or after the last frost of spring. They should be sown at a depth of 0.12 inches (3 mm). If grown indoors first, then Cirsium takes about 2 to 3 weeks to germinate at a temperature of 70 to 75 degrees Fahrenheit (21 to 24 degrees Celsius). The seedlings should be planted out in early spring when it is still possible to get a frost with a spacing of about 2 feet (60 cm).
Cirsium thrives in full sun and poor, average, or reaches soil that is moist but well-drained. Plants require little care, but deadheading limits their tendency to self-sow. They generally self-sow only in moderation, and unlike weedy thistles, the seedlings are easy to pull up. Use Thistles in mixed beds, herb gardens, or meadow-like plantings.
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