There are about 200 species of biennials and perennials, in this genus. They occur in a variety of habitats in Northern temperate regions, including grassy mountain slopes, stream sides or moorland meadows, and dry or moist alpine and subalpine meadows. They have spiny leaves and bear heads of tubular, purple, red, yellow or sometimes white flowers. Many are invasive, spreading by means of rhizomes, or self seeding. Those listed here are useful border plants or suitable for damp meadows in a wild garden.
Grow in moist but well drained soil in full sun. Dead head to prevent self seeding. Divide perennial from autumn to spring.
Prone to powdery mildew and rust.
C. rivulare ‘Atropurpureum’– This clump forming, spreading perennial from Central and Southwestern Europe into Russia grows 4′ feet tall and half as wide. It produces narrowly elliptic to oblong-lance shaped, smooth edged to pinnatifid, prickly, dark green leaves, to 18″ long, softly hairy beneath. In early and mid summers atop of erect stems it carries spherical, pincushion like, deep crimson flowers, 1 1/4″ across.