Western maidenhair fern is one of the easiest ferns in the forest to recognize. A thin, shiny stalk, dark reddish brown to nearly black, forks near the top and spreads the blade into a wide fan or horseshoe of small, oblong leaflets. Fronds can be well over a foot long, and plants often grow in dense clusters that arch or droop over wet rock.
It needs steady moisture and shade. You find it on stream banks, in moist, humus-rich woods, on wet cliffs and in the spray zones of waterfalls, which makes it a familiar companion on waterfall hikes. It grows from the lowlands to the middle slopes of the mountains and becomes scarcer the higher you go.
Turn over a fertile leaflet and you will see that its outer edge folds under to cover the spore cases, instead of the spores sitting in exposed dots as on many ferns.
For years this fern was lumped with the eastern maidenhair fern, and many older books still use that name. Botanists recognized it as a separate species in 1991. Look for it on shaded, dripping rock faces along lower-elevation creek and waterfall trails.
How to identify it
Shiny, wiry stalks, dark reddish brown to purplish black, fork at the top into a fan- or horseshoe-shaped blade about 2 to 18 inches across. The many small leaflets are oblong, smooth along the lower edge and cut into small lobes along the upper edge. On fertile leaflets the outer margin rolls under to cover the spores.
Habitat
Moist, shady woods, stream banks, wet cliffs and the spray zones of waterfalls, from the lowlands to middle mountain elevations. It grows throughout western Oregon and Washington and becomes less common as elevation increases.
Sightings in the forest
693 research-grade sightings in Mt. Hood National Forest on iNaturalist, most recently on October 28, 2026. See them on iNaturalist →