Iris x histrioides 'Katharine Hodgkin'

Wer kennt sich aus mit diesen Iris? Die Katharina taucht auch auf als I. reticulata Sorte. Wie ist´s nun botanisch richtig?

Who can tell me if this kind of Iris is a kind of I. reticulata or a hybrid of I.reticulata and I. histrioides?

Anyway.... I always wanted to have these bulbs and happened to get three of them on a market last year in Berlin. I am a bit disappointed to see only one blossom coming up. The colours are absolutly unusual, it´s a light greenish blue with white stripes. In one of the alpine forums I have seen wonderful photos , one blossom next to the other like a carpet if iris. What do I have to do, to persuade thes bulbs to stay and prosper...?