Carlina is a genus of thistles found in North Africa, parts of Asia, and Europe. These plants are widely distributed in the Mediterranean region, where they have historically been used for food and in the preparation of herbal medicines. These plants can be observed growing in the wild in many regions and they can also be deliberately cultivated as ornamentals and in herb gardens. Garden supplies and nurseries may stock seedlings and seeds, and can order them by special request.
Like other thistles, plants in the genus Carlina have numerous thorns covering their leaves, flowerheads, and stems. The flowers are white to pink and purple, and close up for protection in inclement weather. When open, the flowers are heavily tufted and have a fluffy or puffy appearance. Grown ornamentally, these thistles can be suitable for decorative borders and backdrops. It is advisable to keep them well clear of paths to minimize injuries caused by the thorns and to be alert to the spread of thistles to other areas of the garden, as the seeds will travel in the air.
There are approximately 30 thistle species in the Carlina genus, with the most abundant being C. vulgaris, the common carline thistle. Other species include the so-called “stemless carline thistle,” known for producing flowers directly in the middle of rosettes of leaves, with no stems to separate the flowers from the leaves. These thistles are hardy to USDA zone four and thrive in a variety of soil conditions, including poor soil. They readily reseed if the flowers are allowed to mature and can also be grown from seed.
Flower heads can be eaten while immature, like globe thistles. Thistles in the Carlina genus are not an abundant source of nutrition and they can be challenging to eat, as they tend to be long on prickles and short on edible flesh. In traditional medicine, carline thistles are used as diuretics and in the treatment of infection. The plants have antibacterial compounds, making them very suitable in the treatment of some infectious diseases.
In some regions, Carlina thistles can become invasive and may displace native species. Before planting a non-native species, it is advisable to check a local plant listing to see if it can be grown safely. Such listings usually discuss alternatives to invasive plant species to allow gardeners to make a more sound environmental choice. Advice can also be obtained through a local agricultural extension or gardening society, and nurseries often have advice on invasive species and alternatives as well.