It is native to southwestern Washington, western Oregon, and northwestern California.

It occurs along roadsides and in grasslands and forest openings at low to middle elevations.

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.