[Holly Ferns and Sword Ferns: The Genus Polystichum in the Columbia River Gorge of Oregon and Washington]

Imbricate sword fern growing from a horizontal crack in a rock on open slopes at the Labyrinth in the mid-Columbia River Gorge..........February 28, 2010.

Ventral and dorsal leaflet surfaces of imbricate sword fern. Note the spine-tipped teeth which are more outwards pointing than those of the similar western sword fern (Polystichum munitum) which is found in the forest in this region. Found growing in a horizontal crack in a rock on open slopes at the Labyrinth in the mid-Columbia River Gorge..........February 28, 2010.

Imbricate sword fern growing in shade along the Lyle Cherry Orchard Trail on a basalt outcrop above the SR 14 highway tunnel east of Lyle, WA..........March 16, 2017.