"This is probably the best all-round Pacific Coast native iris for cultivated gardens… [It] hybridizes readily with other Pacific Coast irises, and some natural hybrid populations have been given their own names, such as the "Marin Iris" of the Coast Ranges north of San Francisco. Douglas Iris is generous with its flowers, each branched stem bearing two or three blossom. Flowers are light blue-violet to dark purple, sometimes creamy white or pure white, rarely light yellow"
—Nora Harlow and Kristin Jakob,
Wild Lilies, Irises, and Grasses, 2003