[Woodferns: The Genus Dryopteris in the Cascade Mountains of Oregon and Washington]

Spreading Woodfern, Spreading Wood Fern, Northern Woodfern

Dryopteris expansa

Synonyms: Dryopteris assimilis, Dryopteris dilatata, Dryopteris dilitata var. americana, Nephrodium expansum

Spreading Woodfern, Spreading Wood Fern, Northern Woodfern: Dryopteris expansa (Synonyms: Dryopteris assimilis, Dryopteris dilatata, Dryopteris dilitata var. americana, Nephrodium expansum) - Spreading Woodfern, Spreading Wood Fern, Northern Woodfern: Dryopteris expansa (Synonyms: Dryopteris assimilis, Dryopteris dilatata, Dryopteris dilitata var. americana, Nephrodium expansum)

Spreading woodfern as seen along trails just east of Kalama Falls, WDFW lands west of FS Road 81 and about 2 miles southwest of Kalama Horse Camp (southwest of the Mt. St. Helens National Volcanic Monument boundary)..........December 6, 2017.

Close-up of sporecases of Dryopteris expansa

This photo shows a close-up of the underside of the frond of spreading woodfern as seen along trail #3385 in meadows about one-quarter mile north of Moon Point in the Willamette National Forest.........July 12, 2008.

Underside of frond of Dryopteris expansa

This photo shows another close-up of the underside of the frond of spreading woodfern as seen along trail #3385 in meadows about one-quarter mile north of Moon Point in the Willamette National Forest.........July 12, 2008.

Frond of spreading woodfern: Dryopteris expansa - Frond of Dryopteris expansa

This photo shows the frond of spreading woodfern as seen along trail #3385 in meadows about one-quarter mile north of Moon Point in the Willamette National Forest........July 12, 2008.

Spreading Woodfern, Spreading Wood Fern, Northern Woodfern: Dryopteris expansa (Synonyms: Dryopteris assimilis, Dryopteris dilatata, Dryopteris dilitata var. americana, Nephrodium expansum) - Spreading Woodfern, Spreading Wood Fern, Northern Woodfern: Dryopteris expansa (Synonyms: Dryopteris assimilis, Dryopteris dilatata, Dryopteris dilitata var. americana, Nephrodium expansum)

Spreading woodfern as seen at left along trails near Kalama Falls, Merrill Lake Conservation Area (Washington Department of Natural Resources)...........December 5, 2017. The image at right shows a spreading woodfern as seen along the Dry Creek Trail #194, Gifford Pinchot National Forest.....September 27, 2025..

Spreading Woodfern, Spreading Wood Fern, Northern Woodfern: Dryopteris expansa (Synonyms: Dryopteris assimilis, Dryopteris dilatata, Dryopteris dilitata var. americana, Nephrodium expansum) - Spreading Woodfern, Spreading Wood Fern, Northern Woodfern: Dryopteris expansa (Synonyms: Dryopteris assimilis, Dryopteris dilatata, Dryopteris dilitata var. americana, Nephrodium expansum)

Spreading Woodfern, Spreading Wood Fern, Northern Woodfern: Dryopteris expansa (Synonyms: Dryopteris assimilis, Dryopteris dilatata, Dryopteris dilitata var. americana, Nephrodium expansum)

Spreading woodferns observed along the Dry Creek Trail #194, Gifford Pinchot Nationl Forest.....December 1, 2021.

Spreading Woodfern, Spreading Wood Fern, Northern Woodfern: Dryopteris expansa (Synonyms: Dryopteris assimilis, Dryopteris dilatata, Dryopteris dilitata var. americana, Nephrodium expansum) - Spreading Woodfern, Spreading Wood Fern, Northern Woodfern: Dryopteris expansa (Synonyms: Dryopteris assimilis, Dryopteris dilatata, Dryopteris dilitata var. americana, Nephrodium expansum)

Spreading woodfern observed along the Lewis River Trail #31 about one-quarter mile upstream from the bridge over the Lewis River at Forest Road #9039, Gifford Pinchot National Forest......June 18, 2024.
Paul Slichter