There are a few different forms of Iris unguicularis ‘Alba’. About thirty years ago I raised a really good clone from seed, which should perhaps be given a clonal name as it is so much better than the older, thin petalled, rather pinched looking white selections.
One of the best plants for difficult, dry spots even in shade, this Iris makes evergreen clumps of narrow arching leaves. During winter and early spring, large, creamy white flowers with lovely yellow markings are produced.