For Oron's note on looking after
Iris unguicularis click
here. This Mediterranean iris is extremely adaptable, and as well as flowering in deep shade also flowers happily in full sun on a hot south-facing slope in our Greek garden. (As John has pointed out, if you divide the clumps the time for this is autumn.)
Another dependable iris for unwatered mediterranean-climate gardens, also happy in full sun and in partial shade, is
Iris x
germanica.