Actaea simplex Carbonella

Cimicifuga or Actaea simplex 'Carbonella' is one of the darkest varieties of bugbane. Resembling the cultivar 'Brunette', it is distinguished by its more compact habit, smaller size, and very late flowering. It develops shiny, deeply divided foliage that is very dark, ranging from chocolate to purple. This very hardy perennial forms a beautiful clump from which tall, arching, and flexible stems emerge in autumn, densely covered in pink buds that open into lightly scented white flowers. It establishes slowly in rather moist soil, forming bushy tufts with an interesting architectural appearance, particularly in partially shaded borders, at a time when flowers are scarce.

Actaea simplex, also known as Cimicifuga simplex, is a deciduous herbaceous plant of the buttercup family native to forests in Japan and deep eastern Siberia, from Mongolia to the Russian Far East, as far as Sakhalin and Kamchatka.

'Carbonella' is the dark purple form of this extremely hardy perennial. Growing from a knotty rhizome with fibrous roots arranged in compact masses, this plant slowly forms bushy tufts reaching 90 cm (35in) high when in flower, with a minimum spread of 40 cm (16in). Its stems are covered in large, compound leaves that are highly dissected, with toothed leaflets as elegant as those of astilbes. They take on a very dark purple colour, appearing chocolatey in shade. Flowering occurs in autumn with large, erect or arching terminal inflorescences in purple spikes measuring 10 to 20 cm (4 to 8in) in length covered in pink buds that open into small, lightly scented star-shaped flowers smelling of vanilla. This flowering is very attractive to butterflies and provides a good source of nectar.

Bugbane 'Carbonella' will thrive in partial shade, in the dappled light of a clear understory or at the edge of a forest, in deep soil that retains moisture. This variety tolerates root competition quite well. At the back of borders, its architectural silhouette and bright flowers will create a beautiful background for perennials that have finished flowering at the end of summer. Its dark foliage pairs well with the pink and blue stars of asters, as well as with hardy hydrangeas, fuchsias, and ferns. This plant is very graceful in a slightly wild area and will also make a beautiful focal point when planted in a large pot on the terrace. Its flowers can be used to create lovely bouquets.