Carlina acanthifolia - Carline Thistle

Carlina acanthifolia, the acanthus-leaved carline, is one of the most beautiful plants for dry rock gardens for enthusiasts of graphic flowers on poor soil. Its spiny rosette, pressed flat to the ground, produces in summer a large, straw-yellow to golden head adorned with silvery bracts. Sometimes called cardabelle or sun-thistle, this beautiful species from the southern mountains is both very hardy and drought-tolerant.

This wild plant belongs to the Asteraceae family. Its most commonly used vernacular names are acanthus-leaved carline, cardabelle, sun-thistle, chardousse and shepherd's barometer. Its main botanical synonyms are Carlina acanthifolia var. argentea, Carlina chardousse and Chromatolepis magna. It is a short-lived perennial, more or less semelparous: it can devote one or more seasons to forming its rosette, flower, then disappear after producing its seeds. In a suitable soil, a few seedlings can ensure its continuity. It grows naturally in dry lawns, rocky meadows, the Causses, open slopes and calcareous soils of mountains or mid-altitude. It is found in Europe, particularly in France, Spain, Italy and further east to the Balkans and Ukraine. This plant does not exceed 5 to 10 cm in height, but its rosette can spread 30 to 40 cm. The leaves are large, deeply cut, tough, spiny on the lobes, of a grey-green to whitish colour, lighter on the underside. They are arranged in a circle, pressed flat to the ground, and remain decorative for a good part of the year. Flowering occurs from July to September. The inflorescence is a solitary head, stemless, measuring 10 to 15 cm in diameter. What one first takes for petals corresponds to the inner bracts of the involucre, long, radiating, pale yellow, straw-yellow or golden. In the centre, the small tubular flowers form a dense disc, visited by bees and butterflies. The fruits are achenes with an egret that will be dispersed by the wind. The carline develops a taproot well adapted to drought, but which tolerates transplanting poorly.
The cardabelle is linked to a well-known tradition of the Causses: its dry head was fixed on doors, both as a good luck charm and as a natural barometer, because it closes when the air becomes humid. Plants observed in the wild should not be picked: this species is protected or regulated in several French regions.

In the garden, plant this carline in full sun, among stones, in a stony, calcareous soil that dries quickly after rain. It is used alone or in small groups, as its rosette cannot tolerate competition from overly spreading perennials. You can pair it with other dry-ground plants such as the low-growing Teucrium ackermannii , the Festuca glauca ‘Elijah Blue’ which forms small blue tufts around it, the Santolina ‘Lemon Fizz’ , and thistles from Echinops (azure balls).