Iris lacustris (also known as dwarf lake iris), is a rhizomatous, beardless perennial plant, native to the Great Lakes region of eastern North America. It has lavender blue or violet-blue flowers, a very short stem and long fan-like green leaves. It is cultivated as an ornamental plant in temperate regions. It is closely related to Iris cristata (another North American crested iris). It grows on the Great Lakes shorelines in cool, moist lake shore air.
It is tolerant of a range of soils, but prefers moist, slightly acidic neutral soils.
It flowers mostly in semi-open habitats with partial sun. Although it can tolerate sunny sites.