The plant family that takes its name from the buttercup contains some of our best-loved garden flowers. The cheering anemones, marsh marigolds like golden chalices, intricately pleated and spurred columbines, soaring delphinium, mysterious cowl-shaped monkshoods - as well as the clematis in all its glorious forms - are all close relations. There are links, too, between the vine-like leaves of Japanese anemones, the fennel strands of love-in-a-mist and the ferny foliage of thalictrums.