Dougl. ex Lindl.
Iris tenax is a species of Iris native to southwestern Washington and western Oregon. It is known as the tough-leaved iris, the Oregon iris or more colloquially, Flag. It occurs along roadsides and in grasslands and forest openings at low to middle elevations. One subspecies is also known from northern California.
Like most irises, it has large and showy flowers. The flowers bloom in mid to late spring and are usually lavender-blue to purple, but blooms in white, yellow, pink, and orchid shades are known to sometimes occur. The leaves are very slender for an iris, seldom over 5 mm broad; the plant is often mistaken for a type of grass when not in bloom. Its rhizomes spread slowly, causing the plant to grow in a tight clump.
Its species name (tenax) means "tough" or "tenacious" and is in reference to the strong, fibrous leaves of the plant, which were used by indigenous peoples for braiding into snares and other cordage.
- Hitchcock, Charles Leo and Cronquist, Arthur. Flora of the Pacific Northwest. University of Washington Press, ISBN 0-295-95273-3.
- Kozloff, Eugene N. Plants and Animals of the Pacific Northwest. ISBN 0-295-95597-X.
- Pojar, Jim and MacKinnon, Andy. Plants of Coastal British Columbia. Lone Pine Publishing, ISBN 1-55105-042-0.