Was leafing through a 1939 Carl A. Hansen Nursery catalog from Brookings,
South Dakota, and noticed the offer of "Hansen's new Shilka everblooming
orchid Iris. The offer was derived from collections made by Carl A.
Hansen near the town of Shilka, in the wilds of Siberia.

Description says it bloomed 6-8 weeks after all other irises were gone.
Wide spreading blooms, single or double, in delicate tones of orchid and
blue, mingled with creamy white. Delicately fragrant.

What Iris species is this?

Fred Boutin