Osmunda claytoniana L.

Interrupted fern

About plant names...

Interrupted? How can a fern be interrupted? The answer seems a little silly to me: brown fertile leaflets "interrupt" the green sterile leaflets on larger fronds. These ferns are natives of eastern Asia and North America.

Identification: Fern fronds are up to 35" (90 cm) long and 8" (20 cm) wide. Spore-bearing leaflets are brown, appearing in the middle of the sterile green fronds, the most obvious identifying characteristic. The leaf stalk has a round cross-section.

Interrupted fern, Osmunda claytoniana, in Lac-Mégantic, Quebec, by Circeus, 7/30/2005.

Online References:

Earl J.S. Rook's Flora, Fauna, Earth, and Sky ... The Natural History of the Northwoods

The Connecticut Botanical Society's Connecticut wildflowers site

KgNaturePhotography.com

The Hardy Fern Library

Wikipedia

References:

Cobb, Boughton, Farnsworth, Elizabeth & Lowe, Cheryl, Peterson Field Guides: Ferns of Northeastern and Central North America, Houghton Mifflin Company, 2005, p. 174

5/11/2013 · Townsend Wildlife Management Area, Townsend, Mass­a­chu­setts
≈ 7 × 9" (17 × 23 cm)

5/31/2010 · Mt. Lebanon St., Pepperell, Mass­a­chu­setts
≈ 31 × 39" (78 × 100 cm)

5/13/2012 · Lowell-Dracut-Tyngsboro State Forest, Lowell, Mass­a­chu­setts
≈ 14 × 21" (34 × 52 cm)

5/25/2023 · Maquoit Bay Conservation Land, Brunswick, Maine

9/13/2020 · Hidden Valley Nature Center, Jefferson, Maine
≈ 7 × 4½" (18 × 12 cm)

5/11/2013 · Townsend Wildlife Management Area, Townsend, Mass­a­chu­setts
≈ 9 × 12" (24 × 30 cm)

5/14/2013 · Beaver Brook Assn Conservation Lands, Rte. 130, Hollis, New Hamp­shire
≈ 4½ × 7" (12 × 18 cm)

5/18/2021 · Cathance River Nature Preserve, Topsham, Maine
≈ 4½ × 7" (11 × 17 cm)

5/18/2012 · Mine Falls Park, Nashua, New Hamp­shire
≈ 8 × 12" (20 × 31 cm)

5/15/2010 · Garden in the Woods, Framingham, Mass­a­chu­setts
≈ 21 × 14" (52 × 34 cm)

9/13/2020 · Hidden Valley Nature Center, Jefferson, Maine
≈ 8 × 12" (20 × 31 cm)

6/9/2016 · Monhegan Island, Maine

6/20/2021 · Maquoit Bay Preserve, Brunswick, Maine
≈ 3 × 5" (8.4 × 12 cm)

9/20/2009 · Wild Gardens of Acadia, Acadia National Park, Bar Harbor, Maine
≈ 15 × 10" (39 × 26 cm)

8/22/2020 · Crossbill Trail, Hidden Valley Nature Center, Jefferson, Maine
≈ 6 × 10" (16 × 24 cm)

Osmunda claytoniana description by Thomas H. Kent, last updated 11 Jul 2023.

© FloraFinder.org. All rights reserved.

Once the spore-bearing fertile portions are no longer needed, they wither and disappear, leaving the “interruption.” · 6/17/2016 · Blue Trail, Willard Brook State, Ashby, Mass­a­chu­setts

5/14/2013 · Beaver Brook Assn Conservation Lands, Rte. 130, Hollis, New Hamp­shire
≈ 19 × 23" (47 × 57 cm)

5/20/2023 · Knight’s Pond Preserve, Cumberland, Maine

9/20/2009 · Wild Gardens of Acadia, Acadia National Park, Bar Harbor, Maine
≈ 21 × 31" (52 × 78 cm)

8/28/2020 · Jack’s and Litchfield Trails, Chase Reserve, Brunswick, Maine
≈ 10 × 6" (24 × 16 cm)

9/20/2009 · Wild Gardens of Acadia, Acadia National Park, Bar Harbor, Maine
≈ 21 × 14" (52 × 34 cm)

5/13/2012 · Lowell-Dracut-Tyngsboro State Forest, Lowell, Mass­a­chu­setts
≈ 9 × 14" (23 × 35 cm)

6/20/2021 · Maquoit Bay Preserve, Brunswick, Maine
≈ 10 × 7" (25 × 16 cm)

5/14/2013 · Beaver Brook Assn Conservation Lands, Rte. 130, Hollis, New Hamp­shire
≈ 6 × 9" (16 × 23 cm)

6/9/2016 · Monhegan Island, Maine

5/15/2010 · Garden in the Woods, Framingham, Mass­a­chu­setts
≈ 24 × 16" (62 × 41 cm)

6/9/2016 · Monhegan Island, Maine

6/12/2023 · Viles Arboretum, Augusta, Maine

6/9/2016 · Monhegan Island, Maine

5/13/2012 · Lowell-Dracut-Tyngsboro State Forest, Lowell, Mass­a­chu­setts
≈ 12 × 17" (29 × 44 cm)

5/13/2012 · Lowell-Dracut-Tyngsboro State Forest, Lowell, Mass­a­chu­setts
≈ 9 × 12" (23 × 29 cm)

6/9/2016 · Monhegan Island, Maine

5/18/2021 · Cathance River Nature Preserve, Topsham, Maine
≈ 7 × 8" (16 × 20 cm)

Range: Zones 3-8:

About this map...