Round, faintly prickly heads of tiny, soft green flowers are borne on much branched, stiff stems that rise from a dense rosette of long, slightly spiky leaves. In time the flowers turn entirely white. As these are grown from seed, sometimes the flowers can be soft blue-grey, at other times pure white. Great for 'modern' style planting or adding an upright accent to a border, especially one that is dry. However this has proved to be perennial in our clay-loam soil too.