This is the Red Valerian or Pretty Betsy of Britain. It flourishes in chalky soils in plenty of sunshine, and is an effective border plant 2-3 ft. high, its dense clusters of crimson-purple flowers being also useful for cutting from June to September. There is also a pretty white-flowered variety. Both may be raised from seeds and division.

C. macrosiphon is another species, 2-3 ft. high, with very bright crimson flowers. There is also a white variety and a dwarf dense-growing one called nana. They must be raised from seeds as they are annuals.