Iris lazica is blooming freely now, and the big blue flowers are certainly welcome at this time of year. It's very similar to, and related to, Iris unguicularis. To tell the truth, I'm not sure how to tell them apart. Iris lazica has the reputation of being hardier than I. unguicularis, and for garden purposes it might be a better choice because hardier or not it generally blooms later. This year the two were in bloom for several weeks together.
The plant of Iris lazica growing here is in a cold frame, but I've seen it in the open garden in other local gardens.