Cells on pinnule margins regular in shape, margins appearing entire; adaxial epidermal cells averaging less than 120 µm. Spores averaging 39--45 µm. 2 n = 76.

Sporulating summer--fall. Cliffs and rocky slopes; usually on granitic or volcanic substrates; 100--2800 m; Alta., B.C., Sask.; Calif., Idaho, Mont., Nev., Oreg., Utah, Wash., Wyo.

The leaves of Woodsia oregana subsp. oregana tend to be narrower and less glandular than those of subsp. cathcartiana . The two subspecies hybridize in the narrow region of sympatry; hybrids are sterile triploids with malformed spores.