Iris x robusta 'Gerald Darby'

The purple-blue flowers that white towards the base of the slender petals, sit on long, arching very darm purple stems that rise from a broad clump of long, shiny deep green leaves. Each stem produces 4 or 5 flowers. In spring the leaves are particularly handsome as they emerge heavily tinged with purple. I find that in a shady spot it can be in bloom for a month. Can flowers from mid June into July.