Ken Shannik wrote in our local rock garden site on Iris 'Grey Mist': I'm not sure how this came to be know as Iris sibirica but in a recent discussion I learned that the late Don Armstrong collected this in the mountains of Washington or Oregon. As such it wouldn't be Iris sibirica. Possibly Iris missouriensis - the Western Flag Iris? Any Iris experts care to chime in? I'm told it comes true from seed. I suppose it could be possible Iris sibirica has naturalized but... Iris 'Grey Mist' - a better representation of it's colour in sun. It only grows to about a 20" tall.
Don Armstrong was a great and generous plantsman friend who gardened in Vancouver, BC. he always seemed to have the best form of everything. Gtown in the some shade it can be an iff white which is magnifient in foggy weather. We assumed it was a siberica for years never knowing the full story and never having see I. missouriensis!
In need of a confirmation. Appologies for the photo sizes but I like many others own an Apple, a 50 minute post.
johnw