Scales of stems and petiole bases usually concolored or with a few isolated, dark, occluded cells, scales ovate-lanceolate. Pinnae with longest hairs composed of 2--5 cells. Indusial segments narrow, often filamentous distally. Spores averaging 42--50 µm. 2 n = 76. Sporulating summer--fall. Cliffs and rocky slopes; found on variety of substrates including both granite and limestone; 100--4000 m; Alta., B.C., Sask., Yukon; Alaska, Calif., Colo., Idaho, Mont., Nev., Oreg., Utah, Wash., Wyo. Woodsia scopulina subsp. scopulina is known to hybridize with subsp. laurentiana at localities where the two grow in close proximity. The resultant triploids have malformed spores and appear to be sterile.